The objective of this paper is to develop a new design of a voltage controlled microwave oscillator by using the method of negative resistance in order to fabricate VCO with very good performance in terms of tuning rang, phase noise, output power and stability. The use of hybrid microwave integrated circuit technology’s (HMIC) offers a lot of advantage for our structure concerning size, cost, productivity, and Q factor. This VCO is designed at [480MHz; 1.4GHz] frequency for applications in the phase locked loop (PLL) for signal tracking, FM demodulation, frequency modulation, mobile communication, etc. The different steps of studied voltage controlled oscillator’s design are thoroughly described. Initially designed at a fixed frequency meanwhile the use of a varactor allow us to tune the frequency of the second design. It has been optimized especially regarding tuning bandwidth, power, phase noise, consumption and size of the whole circuit. The achieved results and proposed amendment are the product of theoretical study and predictive simulations with advanced design system microwave design software. A micro-strip VCO with low phase noise based on high gain ultra low noise RF transistor BFP 740 has been designed, fabricated, and characterized. The VCO delivers a sinusoidal signal at the frequency 480 MHz with tuning bandwidth 920 MHz, spectrum power of 12.62 dBm into 50 Ω load and phase noise of -108 dBc/Hz at 100 Hz offset. Measurement results and simulation are in good agreement. Circuit is designed on FR4 substrate which includes integrated resonators and passive components.
IRJET- Improved Transformerless Inverter with Common Mode Leakage Current Eli...IRJET Journal
This document describes an improved transformerless inverter that can be used in photovoltaic grid-connected power systems to eliminate common mode leakage currents. It proposes using additional switches and either unipolar or double frequency sinusoidal pulse width modulation to generate a three-level output from the inverter. Simulation results show reductions in total harmonic distortion of the grid current compared to standard designs. A prototype was also built using the double frequency control scheme to validate the approach experimentally.
A Novel Configuration of A Microstrip Power Amplifier based on GaAs-FET for I...IJECEIAES
Power Amplifiers (PA) are very indispensable components in the design of numerous types of communication transmitters employed in microwave technology. The methodology is exemplified through the design of a 2.45GHz microwave power Amplifier (PA) for the industrial, scientific and medical (ISM) applications using microstrip technology. The main design target is to get a maximum power gain while simultaneously achieving a maximum output power through presenting the optimum impedance which is characteristically carried out per adding a matching circuit between the source and the input of the power amplifier and between the load and the output of the power amplifier. A "T" matching technique is used at the input and the output sides of transistor for assure in band desired that this circuit without reflections and to obtain a maximum power gain. The proposed power amplifier for microwave ISM applications is designed, simulated and optimized by employing Advanced Design System (ADS) software by Agilent. The PA shows good performances in terms of return loss, output power, power gain and stability; the circuit has an input return loss of -38dB and an output return loss of -33.5dB. The 1-dB compression point is 8.69dBm and power gain of the PA is 19.4dBm. The Rollet's Stability measure B1 and the stability factor K of the amplifier is greater than 0 and 1 respectively, which shows that the circuit is unconditionally stable. The total chip size of the PA is 73.5× 36 mm 2 .
Design of Negative Resistance Oscillator with Rocord Low Phase NoiseTELKOMNIKA JOURNAL
The aim of this paper is to use a new design of a negative resistance microwave oscillator in order to fabricate oscillator with very good performance in terms of output power, efficiency, stability and phase noise. In this study the new concept of oscillator using distributed resonator and micro-strip circuit elements improve performances of our structure. A micro-strip microwave oscillator with low phase noise based on an NPN silicon planar epitaxial transistor has been designed, fabricated, and characterized. In this design, each step has been conducted by using Advanced Design System (ADS) and following a theoretical study which enable to optimize the different performances of the whole circuit. The oscillator produce a sinusoidal signal with spectrum power of 12.25 dBm at 2.45 GHz into 50 Ω load when polarized at Vcc=15V with DC to RF efficiency of 16. The obtained phase noise of -120 dBc/Hz at 100 Hz offset is the result of the use of high Q factor resonator and the depth study of the parameters of the oscillator. Simulation and measurement results are in good agreement.
IRJET- Fault Location using Discrete Wavelet Transform for Smart Grid Distrib...IRJET Journal
This document presents a method for locating faults in smart grid distribution systems using discrete wavelet transform (DWT). A faulted signal is generated by simulating components of a power system including a voltage source, transmission lines, transformer, and breaker. The faulted signal is extracted using both DWT and discrete Fourier transform (DFT) for comparison. DWT is shown to be better than DFT for fault location as it provides clear representation of the faulted signal in both time and frequency domains. The methodology is tested on a simulated three-phase power system and the results demonstrate the effectiveness of DWT for fault detection and location in smart grids.
DESIGN AND ANALYSIS OF PHASE-LOCKED LOOP AND PERFORMANCE PARAMETERSIJMEJournal1
This document summarizes the design and analysis of a phase locked loop (PLL) circuit simulated in 0.18μm CMOS technology. Key components of the PLL include a phase frequency detector, charge pump, current starved voltage controlled oscillator, and feedback divider. Simulation results show the PLL achieves locking within 100 clock cycles and successfully operates at 1.55GHz with very low jitter of 1.09ns and phase noise of -98.58dBc at 1MHz offset. The PLL circuit draws 6.92mW of power.
This paper relates the new topology and simulations of a fully differential CMOS active filter for mm wave band applications. The advantages of the differential topology over the single ended one are discussed and the quality factor is tuned to insure application requirements, including narrow bandwidth and high selectivity due to a differential negative resistance that reuses the filter’s current. Using this topology enables independent tuning of the quality factor and low power consumption while compensating the resistive loss of the filter. Very high filter performance was obtained with the simulated active inductor based active filter that was designed using CMOS 0.35 µm technology from AMS foundry and that resonates at 30 GHz with a high quality factor of Q > 500.
IRJET- Design and Analysis of Current Starved and Differential Pair VCO for L...IRJET Journal
This document compares the design and analysis of a current starved voltage controlled oscillator (CSVCO) and differential pair voltage controlled oscillator (DAVCO) for low power phase locked loop applications using 180nm CMOS technology. Both circuits were designed and simulated using SPICE simulation software. The CSVCO operates from 0.5V to 1V control voltage and has an average power dissipation of 42 microwatts, while the DAVCO operates from 0.5V to 1.3V control voltage and has an average power dissipation of 1.42 milliwatts. The DAVCO has a higher frequency gain and tuning range but higher power consumption compared to the CSVCO, making the CSVCO more suitable for low power applications
IRJET- Improved Transformerless Inverter with Common Mode Leakage Current Eli...IRJET Journal
This document describes an improved transformerless inverter that can be used in photovoltaic grid-connected power systems to eliminate common mode leakage currents. It proposes using additional switches and either unipolar or double frequency sinusoidal pulse width modulation to generate a three-level output from the inverter. Simulation results show reductions in total harmonic distortion of the grid current compared to standard designs. A prototype was also built using the double frequency control scheme to validate the approach experimentally.
A Novel Configuration of A Microstrip Power Amplifier based on GaAs-FET for I...IJECEIAES
Power Amplifiers (PA) are very indispensable components in the design of numerous types of communication transmitters employed in microwave technology. The methodology is exemplified through the design of a 2.45GHz microwave power Amplifier (PA) for the industrial, scientific and medical (ISM) applications using microstrip technology. The main design target is to get a maximum power gain while simultaneously achieving a maximum output power through presenting the optimum impedance which is characteristically carried out per adding a matching circuit between the source and the input of the power amplifier and between the load and the output of the power amplifier. A "T" matching technique is used at the input and the output sides of transistor for assure in band desired that this circuit without reflections and to obtain a maximum power gain. The proposed power amplifier for microwave ISM applications is designed, simulated and optimized by employing Advanced Design System (ADS) software by Agilent. The PA shows good performances in terms of return loss, output power, power gain and stability; the circuit has an input return loss of -38dB and an output return loss of -33.5dB. The 1-dB compression point is 8.69dBm and power gain of the PA is 19.4dBm. The Rollet's Stability measure B1 and the stability factor K of the amplifier is greater than 0 and 1 respectively, which shows that the circuit is unconditionally stable. The total chip size of the PA is 73.5× 36 mm 2 .
Design of Negative Resistance Oscillator with Rocord Low Phase NoiseTELKOMNIKA JOURNAL
The aim of this paper is to use a new design of a negative resistance microwave oscillator in order to fabricate oscillator with very good performance in terms of output power, efficiency, stability and phase noise. In this study the new concept of oscillator using distributed resonator and micro-strip circuit elements improve performances of our structure. A micro-strip microwave oscillator with low phase noise based on an NPN silicon planar epitaxial transistor has been designed, fabricated, and characterized. In this design, each step has been conducted by using Advanced Design System (ADS) and following a theoretical study which enable to optimize the different performances of the whole circuit. The oscillator produce a sinusoidal signal with spectrum power of 12.25 dBm at 2.45 GHz into 50 Ω load when polarized at Vcc=15V with DC to RF efficiency of 16. The obtained phase noise of -120 dBc/Hz at 100 Hz offset is the result of the use of high Q factor resonator and the depth study of the parameters of the oscillator. Simulation and measurement results are in good agreement.
IRJET- Fault Location using Discrete Wavelet Transform for Smart Grid Distrib...IRJET Journal
This document presents a method for locating faults in smart grid distribution systems using discrete wavelet transform (DWT). A faulted signal is generated by simulating components of a power system including a voltage source, transmission lines, transformer, and breaker. The faulted signal is extracted using both DWT and discrete Fourier transform (DFT) for comparison. DWT is shown to be better than DFT for fault location as it provides clear representation of the faulted signal in both time and frequency domains. The methodology is tested on a simulated three-phase power system and the results demonstrate the effectiveness of DWT for fault detection and location in smart grids.
DESIGN AND ANALYSIS OF PHASE-LOCKED LOOP AND PERFORMANCE PARAMETERSIJMEJournal1
This document summarizes the design and analysis of a phase locked loop (PLL) circuit simulated in 0.18μm CMOS technology. Key components of the PLL include a phase frequency detector, charge pump, current starved voltage controlled oscillator, and feedback divider. Simulation results show the PLL achieves locking within 100 clock cycles and successfully operates at 1.55GHz with very low jitter of 1.09ns and phase noise of -98.58dBc at 1MHz offset. The PLL circuit draws 6.92mW of power.
This paper relates the new topology and simulations of a fully differential CMOS active filter for mm wave band applications. The advantages of the differential topology over the single ended one are discussed and the quality factor is tuned to insure application requirements, including narrow bandwidth and high selectivity due to a differential negative resistance that reuses the filter’s current. Using this topology enables independent tuning of the quality factor and low power consumption while compensating the resistive loss of the filter. Very high filter performance was obtained with the simulated active inductor based active filter that was designed using CMOS 0.35 µm technology from AMS foundry and that resonates at 30 GHz with a high quality factor of Q > 500.
IRJET- Design and Analysis of Current Starved and Differential Pair VCO for L...IRJET Journal
This document compares the design and analysis of a current starved voltage controlled oscillator (CSVCO) and differential pair voltage controlled oscillator (DAVCO) for low power phase locked loop applications using 180nm CMOS technology. Both circuits were designed and simulated using SPICE simulation software. The CSVCO operates from 0.5V to 1V control voltage and has an average power dissipation of 42 microwatts, while the DAVCO operates from 0.5V to 1.3V control voltage and has an average power dissipation of 1.42 milliwatts. The DAVCO has a higher frequency gain and tuning range but higher power consumption compared to the CSVCO, making the CSVCO more suitable for low power applications
This document summarizes the design, simulation, and measurement of a class A power amplifier operating from 2.5GHz to 4.5GHz for use in satellite transponders. The power amplifier was designed using a SZA3044Z BJT transistor in Agilent ADS. Stability and impedance matching networks were designed to maximize gain and minimize reflections. Measurements showed a gain of 26.4dB, input return loss better than -39.8dB, and output return loss better than -49.3dB, meeting most but not all specifications. While improvements are needed, the design process provided insight into challenges in high power amplifier design.
An inverter system applied with the PV source typically has a problem of lower input voltage due to constraint in the PV strings connection. As a countermeasure a DC-DC boost converter is placed in between to achieve a higher voltage at the inverter DC link for connection to the grid and to realize the MPPT operation. This additional stage contributes to losses and complexity in control thus reducing the overall system efficiency. This work discussed on the design and development of a grid-connected quasi-Z-source PV inverter which has different topology and control method compared to the conventional voltage source inverter and able to overcome the above disadvantages. Modelling and performance analysis of the voltage and current controller to achieve a good power transfer from the PV source, as well sycnchronization with the grid are presented in detail. Results from both simulation and experimental verification demonstrate the designed and developed grid-connected qZSI PV inverter works successfully equivalent to the conventional voltage source inverter system.
IRJET- Modified Cascaded H - Bridge Multilevel Inverter for Household AppliancesIRJET Journal
This document describes a study on a modified cascaded H-bridge multilevel inverter for household appliances. The researchers developed a 9-level single phase inverter using 4 H-bridge cells. They used sinusoidal pulse width modulation to generate switching signals and reduce harmonic distortion. Simulations in MATLAB/Simulink showed the output voltage waveform and total harmonic distortion of 9.12%. A hardware prototype was built and tested to verify the design, demonstrating a 53.9V output voltage with 8.22% total harmonic distortion. The modified topology reduces switching losses and improves output capability compared to other multilevel inverter configurations.
This document provides instructions for an experiment on generating a pulse amplitude modulation (PAM) wave using a simple circuit. The experiment aims to modulate the amplitude of a 45 kHz square wave pulse train using a 1 kHz sine wave as the modulating signal. Students will construct three circuits - a sine wave generator, square wave generator, and a PAM modulator using a N-channel field effect transistor and resistors. The PAM modulator circuit diagram is provided. Students are asked to write a laboratory report explaining the theory of PAM modulation, discussing the results obtained for different time periods in relation to circuit component values and signal variations.
A low dropout (LDO) voltage regulator with high power supply rejection ratio (PSRR) and low
temperature coefficient (TC) is presented in this paper. Large 1μF off-chip load capacitor is used to
achieve the high PSRR. However, this decreases the gain and pushes the LDO’s output pole to lower
frequency causing the circuit to become unstable. The proposed LDO uses rail-to-rail folded cascode
amplifier to compensate the gain and stability problems. 2nd order curvature characteristic is used in
bandgap voltage reference circuit that is applied at the input of the amplifier to minimize the TC.
The characteristic is achieved by implementing MOSFET transistors operate in weak and strong
inversions. The LDO is designed using 0.18 μm CMOS technology and achieves a constant 1.8 V output
voltage for input voltages from 3.2 V to 5 V and load current up to a 128mA at temperature between -40 °C
to 125 °C. The proposed LDO is targeted for RF application which has stringent requirement on noise
rejection over a broad range of frequency.
Anything we transmit without protection is being raid by the intruders. Hence it is necessary to impart
security to the signal transmitted. In this paper we present the concept of giving security to the transmitted
power signal which is to be received by a receiver in a wireless medium. The present techniques of wireless
power transmission consists of a pair of strongly magnetically coupled resonators that allow power
transmission of tens of watts over a few meters, but anything without security becomes unreliable. With the
goal in achieving security to the power signal, we introduce the concept of encryption decryption algorithm
using RF module.
Harmonic current reduction by using the super lift boost converter for two st...IJSRED
The document discusses using a super lift boost converter to reduce harmonic current in a two-stage single-phase inverter. A super lift boost converter has faster performance than a standard DC-DC converter and can boost input voltage. It allows for increased voltage loop gain compared to a cascade boost converter with no conversion losses. The paper experimentally verifies this approach using a PIC microcontroller and other hardware components like MOSFETs and voltage regulators. Firefly optimization algorithms are also used in the simulation to reduce complexity and oscillations for maximum power point tracking. The conclusion is that the super lift boost converter reduces harmonics compared to a standard DC-DC converter with fast performance and reduced conversion time.
A 60 GHz CMOS Power Amplifier for Wireless CommunicationsIJECEIAES
This paper presents a 60 GHz power amplifier (PA) suitable for wireless communications. The two-stage wideband PA is fabricated in 55 nm CMOS. Measurement results show that the PA obtains a peak gain of 16 dB over a -3 dB bandwidth from 57 GHz to 67 GHz. It archives an output 1 dB compression point (OP1dB) of 4 dBm and a peak power added efficiency (PAE) of 12.6%. The PA consumes a total DC power of 38.3 mW from a 1.2 V supply voltage while its core occupies a chip area of 0.45 mm 2 .
Microwave couplers are passive devices that divide and distribute power between transmission lines. There are different types of couplers including directional couplers, hybrid couplers, and Lange couplers. Key specifications for couplers include coupling factor, isolation factor, directivity, and losses. Recent developments aim to reduce size and increase bandwidth, such as using novel phase inverter designs in hybrid couplers.
Effect of DC voltage source on the voltage and current of transmitter and rec...journalBEEI
A solenoid supplied by alternating current (AC) voltage generates electromagnetic which has a field area depends on the level of supplied voltage and current flows through the solenoid. The electromagnetic filed can be captured by the other solenoid in the field area. This concept can be applied in a wireless power transfer (WPT) as presented in this paper. The WPT has transmitter coil and receiver coil which each has form of solenoid. The transmitter coil is connected a half bridge circuit to generate AC voltage on the transmitter coil which transferred to the receiver coil. In the experimental set up, the receiver coil is supplied by DC voltage source and it is changed to observe its effect on the voltage and current on the transmitter and receiver coil of the WPT system.
Design of 2MHz OOK transmitter/receiver for inductive power and data transmis...IJECEIAES
In this work a 2 MHz on-off keying (OOK) transmitter/receiver for inductive power and data transmission for biomedical implant system is presented. Inductive link, driven by a Class E power amplifier (PA) is the most PA used to transfer data and power to the internal part of biomedical implant system. Proposed transmitter consists of a digital control oscillator (DCO) and a class E PA which uses OOK modulation to transfer both data and power to a biomedical implant. In proposing OOK transmitter when the transmitter sends binary value “0” the DCO and PA are turned off. With this architecture and 2 MHz carrier wave we have implemented a wireless data and power transfer link which can transmit data with data rate 1Mbps and bit error rate (BER) of 10-5. The efficiency of power transfer is 42% with a 12.7 uH transmitter coil and a 2.4 uH receiver coil and the power delivered to the load is about 104.7 mW. Proposed transmitter is designed for output power 4.1V. OOK receiver consists of an OOK demodulator, powered by rectified and regulated 5V p-p RF signal across the receiver coil. The supply voltage of proposed voltage regulator is 5 V with 9mV/V line regulation of. All circuits proposed in this paper were designed and simulated using Cadence in 0.18 um CMOS process.
Reconfigurable ultra wideband to narrowband antenna for cognitive radio appli...TELKOMNIKA JOURNAL
Frequency reconfigurable antennas are very attractive for many wireless applications.They offer many advantages such as simplicity and compactness. In this electronicpaper, we propose a reconfigurable antenna operating in the S and C bands. Theproposed antenna uses a BAP65-02 RF diode to switch between the ultra widebandfrom 2.92 to 6.19 GHz to the narrowband from 2.92 to 3.93 GHz. The ultra widebandis obtained by a partial rectangular ground plane with a symmetrical rectangular slotand the narrowband is obtained by adding a parasitic element electrically connectedto the ground plane by the PIN diode when it is positively biased. This patch antennaoperates in the Federal Communications Commission band (FCC) and can be used forbiomedical applications such as radiometry imaging. The numerical simulation resultsbased on the finite element method and the finite integral method show a very goodagreement between them.
This document summarizes a 60 GHz distributed active transformer (DAT) implemented in a 130nm silicon-germanium process that achieves a record output power of 23 dBm (200 mW). Key points:
1) The DAT utilizes stacked coupled wires to achieve a high coupling factor of 0.8 at 60 GHz, enabling efficient power combining and impedance transformation.
2) A two-stage power amplifier combines the power of eight cascode amplifiers using the DAT into a 100 ohm differential load, achieving 13 dB of gain and 6.4% power-added efficiency.
3) The small-area 160x160 micron DAT demonstrates the feasibility of efficient millimeter-wave power combining
IRJET- Reliability Enhancement of Low-Power Sequential Circuits using Power G...IRJET Journal
This document discusses techniques to improve the reliability of low-power sequential circuits using power gating technology. It presents a study on how process, voltage, and temperature variations affect traditional transmission gate pulsed latch circuits. It proposes a new circuit architecture that uses a stack technique with header and footer switches to reduce power leakage during inactive modes. Simulation results show the proposed design has lower power consumption compared to traditional pulsed latch designs in different technologies. The analysis considers the effects on both the pulser and latch to evaluate reliability under variations, and power gating is shown to provide benefits.
DESIGN OF HIGH EFFICIENCY TWO STAGE POWER AMPLIFIER IN 0.13UM RF CMOS TECHNOL...VLSICS Design
This two-stage power amplifier was designed in 0.13um RF CMOS technology for 2.4GHz WLAN applications. It consists of a driver stage using a cascode topology and a power stage using a basic topology. At 1dB compression, it delivers 20.028dBm of output power with 44.669% power added efficiency. Maximum output power is 22.002dBm with 70.196% efficiency. Input and output return losses are -11.132dB and -12.467dB respectively, with a gain of 43.745dB at 1dB compression.
Design Modeling and Simulation of Fuzzy Controlled Svc for Long Over Head Tra...IOSRJEEE
The basic control objectives of a power system are system voltage control, system frequency control, protection and economic operation. Reactive power control is a subset of overall system control and stability. A power system is said to be well designed if it gives a good quality of reliable supply. By good quality is said meant the voltage levels are maintained within the reasonable limits. If the voltage variation is more than a pre specified value, the performance of the equipment suffers and the life of most of the equipment is sacrificed. When power is supplied to a load through transmission line keeping sending end voltage constant, the load voltage undergoes variations depending upon the magnitude of the load. The higher the load greater is the voltage variation. The transmission line distributed parameters through out the line, on light loads or at no loads become predominant and consequently the line supplies charging VAR (generates reactive power). In order to maintain the terminal voltage at the load bus adequate, reactive reserves are needed. FACTS devices like SVC can supply or absorb the reactive power at receiving end bus or at load end bus in transmission system, which helps in achieving better economy in power transfer. The fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory. Fuzzy control is based on fuzzy logic – a logical system which is much closer in sprit to human thinking and nature language than traditional logical system. The fuzzy logic controller (FLC) provides a means of converting a linguistic control strategy based on an expert knowledge into an automatic control strategy. Knowledge acquisition in FLC application plays an important role in determining the level of performance of a fuzzy control system. FLC based on the fuzzy model of a process is needed when higher accuracy and reliability are required. Only small efforts have been expended in applying fuzzy
Mini Project 1 - Amplitude Shift Keying (ASK) ModulatorAIMST University
This document provides instructions for a student laboratory project to build an Amplitude Shift Keying (ASK) modulator circuit. The objectives are to generate a 1 kHz square wave pulse and use it to modulate a 100 kHz carrier signal to produce an ASK modulated output. The circuit uses two Timer IC 555 chips - one configured as an astable multivibrator to generate the pulse signal, and the other as an astable multivibrator modulated by the pulse input to produce the ASK output. Students are asked to construct the circuit on a printed circuit board, test it, and write a laboratory report explaining the theory, design, testing, and results of the project.
The document discusses different types of phase shifters, including ferrite and semiconductor phase shifters. Ferrite phase shifters work by changing the permeability of ferrite material with a magnetic field, thus changing the guided wavelength and phase delay. Semiconductor phase shifters include switched line, loaded line, and switched path designs using PIN diodes or FETs. Digital phase shifters provide precise phase shifts in discrete increments. Phase shifters have applications in communication systems, radar systems, and industrial instrumentation due to their ability to electronically control the phase of RF signals.
Multi-power rail FLR configurable for Digital CircuitsIRJET Journal
This document proposes a multi-power rail configurable fast load regulator (FLR) for digital circuits. The FLR uses dual 1.8V and 3.3V power rails to improve power efficiency by 40% compared to a single 3.3V rail, especially at lower output voltages of 1.0V. The architecture is optimized so that 80% of the current comes from the 1.8V rail at 1.0V output, decreasing as the output voltage increases toward 1.5V. Protection transistors are added to prevent latch-up by ensuring only one power rail is active at a time. Simulation results show the schematic and layout of the proposed FLR.
28 GHz balanced pHEMT VCO with low phase noise and high output power performa...IJECEIAES
This paper presents the study and design of a balanced voltage controlled oscillator VCO for 5G wireless communication systems. This circuit is designed in monolithic microwave integrated circuit (MMIC) technology using PH15 process from UMS foundry. The VCO ensures an adequate tuning range by a single-ended pHEMT varactors configuration. The simulation results show that this circuit delivers a sinusoidal signal of output power around 9 dBm with a second harmonic rejection between 25.87 and 33.83 dB, the oscillation frequency varies between 26.46 and 28.90 GHz, the phase noise is -113.155 and -133.167 dBc/Hz respectively at 1 MHz and 10 MHz offset and the Figure of Merit is -181.06 dBc/Hz. The power consumed by the VCO is 122 mW. The oscillator layout with bias and RF output pads occupies an area of 0.515 mm 2 .
The document describes the design of a low power preamplifier integrated circuit for cochlear implants using a split folded cascode technique. This technique splits the input transistors into two branches with equal aspect ratios, increasing the overall transconductance by 1.414 times compared to a normal folded cascode. Simulations of the proposed preamplifier design in Cadence Virtuoso using a 180nm process show a mid-band gain of 43.7 dB, bandwidth of 18-20 kHz, and input-referred noise of 473.47 nV/√Hz at 4 kHz, while consuming 4.47 μW from a 1.8V supply. The split folded cascode technique enhances performance over normal cascode
The pulse generator which has been implemented in the pulse electric field (PEF) treatment system for food processing is worth to be highlighted and improved. It is parallel with the advancement in semiconductor technology, which offers robust and accurate devices. This research is an effort to produce a low cost, compact and reliable pulse generator as well as equipped with a pulse width modulation (PWM) method for wide selection of frequency and duty cycle. The result shows that the simulation process has proven the theoretical concept to be right and yields the desired outcome based on the designed values. Then, the actual printed circuit board (PCB) has been fabricated to obtain practical results which intended to be compared with the simulation outcomes. Concerning the frequency and its duty cycle, both parameters can be altered without affecting each other. It means by changing the frequency, duty cycle remains the same and vice versa. Thus, this proposed pulse generator achieves its objective and fits to be implemented in PEF treatment technology. It also can replace the conventional pulse forming network (PFN) which is bulky and costly.
This document summarizes the design, simulation, and measurement of a class A power amplifier operating from 2.5GHz to 4.5GHz for use in satellite transponders. The power amplifier was designed using a SZA3044Z BJT transistor in Agilent ADS. Stability and impedance matching networks were designed to maximize gain and minimize reflections. Measurements showed a gain of 26.4dB, input return loss better than -39.8dB, and output return loss better than -49.3dB, meeting most but not all specifications. While improvements are needed, the design process provided insight into challenges in high power amplifier design.
An inverter system applied with the PV source typically has a problem of lower input voltage due to constraint in the PV strings connection. As a countermeasure a DC-DC boost converter is placed in between to achieve a higher voltage at the inverter DC link for connection to the grid and to realize the MPPT operation. This additional stage contributes to losses and complexity in control thus reducing the overall system efficiency. This work discussed on the design and development of a grid-connected quasi-Z-source PV inverter which has different topology and control method compared to the conventional voltage source inverter and able to overcome the above disadvantages. Modelling and performance analysis of the voltage and current controller to achieve a good power transfer from the PV source, as well sycnchronization with the grid are presented in detail. Results from both simulation and experimental verification demonstrate the designed and developed grid-connected qZSI PV inverter works successfully equivalent to the conventional voltage source inverter system.
IRJET- Modified Cascaded H - Bridge Multilevel Inverter for Household AppliancesIRJET Journal
This document describes a study on a modified cascaded H-bridge multilevel inverter for household appliances. The researchers developed a 9-level single phase inverter using 4 H-bridge cells. They used sinusoidal pulse width modulation to generate switching signals and reduce harmonic distortion. Simulations in MATLAB/Simulink showed the output voltage waveform and total harmonic distortion of 9.12%. A hardware prototype was built and tested to verify the design, demonstrating a 53.9V output voltage with 8.22% total harmonic distortion. The modified topology reduces switching losses and improves output capability compared to other multilevel inverter configurations.
This document provides instructions for an experiment on generating a pulse amplitude modulation (PAM) wave using a simple circuit. The experiment aims to modulate the amplitude of a 45 kHz square wave pulse train using a 1 kHz sine wave as the modulating signal. Students will construct three circuits - a sine wave generator, square wave generator, and a PAM modulator using a N-channel field effect transistor and resistors. The PAM modulator circuit diagram is provided. Students are asked to write a laboratory report explaining the theory of PAM modulation, discussing the results obtained for different time periods in relation to circuit component values and signal variations.
A low dropout (LDO) voltage regulator with high power supply rejection ratio (PSRR) and low
temperature coefficient (TC) is presented in this paper. Large 1μF off-chip load capacitor is used to
achieve the high PSRR. However, this decreases the gain and pushes the LDO’s output pole to lower
frequency causing the circuit to become unstable. The proposed LDO uses rail-to-rail folded cascode
amplifier to compensate the gain and stability problems. 2nd order curvature characteristic is used in
bandgap voltage reference circuit that is applied at the input of the amplifier to minimize the TC.
The characteristic is achieved by implementing MOSFET transistors operate in weak and strong
inversions. The LDO is designed using 0.18 μm CMOS technology and achieves a constant 1.8 V output
voltage for input voltages from 3.2 V to 5 V and load current up to a 128mA at temperature between -40 °C
to 125 °C. The proposed LDO is targeted for RF application which has stringent requirement on noise
rejection over a broad range of frequency.
Anything we transmit without protection is being raid by the intruders. Hence it is necessary to impart
security to the signal transmitted. In this paper we present the concept of giving security to the transmitted
power signal which is to be received by a receiver in a wireless medium. The present techniques of wireless
power transmission consists of a pair of strongly magnetically coupled resonators that allow power
transmission of tens of watts over a few meters, but anything without security becomes unreliable. With the
goal in achieving security to the power signal, we introduce the concept of encryption decryption algorithm
using RF module.
Harmonic current reduction by using the super lift boost converter for two st...IJSRED
The document discusses using a super lift boost converter to reduce harmonic current in a two-stage single-phase inverter. A super lift boost converter has faster performance than a standard DC-DC converter and can boost input voltage. It allows for increased voltage loop gain compared to a cascade boost converter with no conversion losses. The paper experimentally verifies this approach using a PIC microcontroller and other hardware components like MOSFETs and voltage regulators. Firefly optimization algorithms are also used in the simulation to reduce complexity and oscillations for maximum power point tracking. The conclusion is that the super lift boost converter reduces harmonics compared to a standard DC-DC converter with fast performance and reduced conversion time.
A 60 GHz CMOS Power Amplifier for Wireless CommunicationsIJECEIAES
This paper presents a 60 GHz power amplifier (PA) suitable for wireless communications. The two-stage wideband PA is fabricated in 55 nm CMOS. Measurement results show that the PA obtains a peak gain of 16 dB over a -3 dB bandwidth from 57 GHz to 67 GHz. It archives an output 1 dB compression point (OP1dB) of 4 dBm and a peak power added efficiency (PAE) of 12.6%. The PA consumes a total DC power of 38.3 mW from a 1.2 V supply voltage while its core occupies a chip area of 0.45 mm 2 .
Microwave couplers are passive devices that divide and distribute power between transmission lines. There are different types of couplers including directional couplers, hybrid couplers, and Lange couplers. Key specifications for couplers include coupling factor, isolation factor, directivity, and losses. Recent developments aim to reduce size and increase bandwidth, such as using novel phase inverter designs in hybrid couplers.
Effect of DC voltage source on the voltage and current of transmitter and rec...journalBEEI
A solenoid supplied by alternating current (AC) voltage generates electromagnetic which has a field area depends on the level of supplied voltage and current flows through the solenoid. The electromagnetic filed can be captured by the other solenoid in the field area. This concept can be applied in a wireless power transfer (WPT) as presented in this paper. The WPT has transmitter coil and receiver coil which each has form of solenoid. The transmitter coil is connected a half bridge circuit to generate AC voltage on the transmitter coil which transferred to the receiver coil. In the experimental set up, the receiver coil is supplied by DC voltage source and it is changed to observe its effect on the voltage and current on the transmitter and receiver coil of the WPT system.
Design of 2MHz OOK transmitter/receiver for inductive power and data transmis...IJECEIAES
In this work a 2 MHz on-off keying (OOK) transmitter/receiver for inductive power and data transmission for biomedical implant system is presented. Inductive link, driven by a Class E power amplifier (PA) is the most PA used to transfer data and power to the internal part of biomedical implant system. Proposed transmitter consists of a digital control oscillator (DCO) and a class E PA which uses OOK modulation to transfer both data and power to a biomedical implant. In proposing OOK transmitter when the transmitter sends binary value “0” the DCO and PA are turned off. With this architecture and 2 MHz carrier wave we have implemented a wireless data and power transfer link which can transmit data with data rate 1Mbps and bit error rate (BER) of 10-5. The efficiency of power transfer is 42% with a 12.7 uH transmitter coil and a 2.4 uH receiver coil and the power delivered to the load is about 104.7 mW. Proposed transmitter is designed for output power 4.1V. OOK receiver consists of an OOK demodulator, powered by rectified and regulated 5V p-p RF signal across the receiver coil. The supply voltage of proposed voltage regulator is 5 V with 9mV/V line regulation of. All circuits proposed in this paper were designed and simulated using Cadence in 0.18 um CMOS process.
Reconfigurable ultra wideband to narrowband antenna for cognitive radio appli...TELKOMNIKA JOURNAL
Frequency reconfigurable antennas are very attractive for many wireless applications.They offer many advantages such as simplicity and compactness. In this electronicpaper, we propose a reconfigurable antenna operating in the S and C bands. Theproposed antenna uses a BAP65-02 RF diode to switch between the ultra widebandfrom 2.92 to 6.19 GHz to the narrowband from 2.92 to 3.93 GHz. The ultra widebandis obtained by a partial rectangular ground plane with a symmetrical rectangular slotand the narrowband is obtained by adding a parasitic element electrically connectedto the ground plane by the PIN diode when it is positively biased. This patch antennaoperates in the Federal Communications Commission band (FCC) and can be used forbiomedical applications such as radiometry imaging. The numerical simulation resultsbased on the finite element method and the finite integral method show a very goodagreement between them.
This document summarizes a 60 GHz distributed active transformer (DAT) implemented in a 130nm silicon-germanium process that achieves a record output power of 23 dBm (200 mW). Key points:
1) The DAT utilizes stacked coupled wires to achieve a high coupling factor of 0.8 at 60 GHz, enabling efficient power combining and impedance transformation.
2) A two-stage power amplifier combines the power of eight cascode amplifiers using the DAT into a 100 ohm differential load, achieving 13 dB of gain and 6.4% power-added efficiency.
3) The small-area 160x160 micron DAT demonstrates the feasibility of efficient millimeter-wave power combining
IRJET- Reliability Enhancement of Low-Power Sequential Circuits using Power G...IRJET Journal
This document discusses techniques to improve the reliability of low-power sequential circuits using power gating technology. It presents a study on how process, voltage, and temperature variations affect traditional transmission gate pulsed latch circuits. It proposes a new circuit architecture that uses a stack technique with header and footer switches to reduce power leakage during inactive modes. Simulation results show the proposed design has lower power consumption compared to traditional pulsed latch designs in different technologies. The analysis considers the effects on both the pulser and latch to evaluate reliability under variations, and power gating is shown to provide benefits.
DESIGN OF HIGH EFFICIENCY TWO STAGE POWER AMPLIFIER IN 0.13UM RF CMOS TECHNOL...VLSICS Design
This two-stage power amplifier was designed in 0.13um RF CMOS technology for 2.4GHz WLAN applications. It consists of a driver stage using a cascode topology and a power stage using a basic topology. At 1dB compression, it delivers 20.028dBm of output power with 44.669% power added efficiency. Maximum output power is 22.002dBm with 70.196% efficiency. Input and output return losses are -11.132dB and -12.467dB respectively, with a gain of 43.745dB at 1dB compression.
Design Modeling and Simulation of Fuzzy Controlled Svc for Long Over Head Tra...IOSRJEEE
The basic control objectives of a power system are system voltage control, system frequency control, protection and economic operation. Reactive power control is a subset of overall system control and stability. A power system is said to be well designed if it gives a good quality of reliable supply. By good quality is said meant the voltage levels are maintained within the reasonable limits. If the voltage variation is more than a pre specified value, the performance of the equipment suffers and the life of most of the equipment is sacrificed. When power is supplied to a load through transmission line keeping sending end voltage constant, the load voltage undergoes variations depending upon the magnitude of the load. The higher the load greater is the voltage variation. The transmission line distributed parameters through out the line, on light loads or at no loads become predominant and consequently the line supplies charging VAR (generates reactive power). In order to maintain the terminal voltage at the load bus adequate, reactive reserves are needed. FACTS devices like SVC can supply or absorb the reactive power at receiving end bus or at load end bus in transmission system, which helps in achieving better economy in power transfer. The fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory. Fuzzy control is based on fuzzy logic – a logical system which is much closer in sprit to human thinking and nature language than traditional logical system. The fuzzy logic controller (FLC) provides a means of converting a linguistic control strategy based on an expert knowledge into an automatic control strategy. Knowledge acquisition in FLC application plays an important role in determining the level of performance of a fuzzy control system. FLC based on the fuzzy model of a process is needed when higher accuracy and reliability are required. Only small efforts have been expended in applying fuzzy
Mini Project 1 - Amplitude Shift Keying (ASK) ModulatorAIMST University
This document provides instructions for a student laboratory project to build an Amplitude Shift Keying (ASK) modulator circuit. The objectives are to generate a 1 kHz square wave pulse and use it to modulate a 100 kHz carrier signal to produce an ASK modulated output. The circuit uses two Timer IC 555 chips - one configured as an astable multivibrator to generate the pulse signal, and the other as an astable multivibrator modulated by the pulse input to produce the ASK output. Students are asked to construct the circuit on a printed circuit board, test it, and write a laboratory report explaining the theory, design, testing, and results of the project.
The document discusses different types of phase shifters, including ferrite and semiconductor phase shifters. Ferrite phase shifters work by changing the permeability of ferrite material with a magnetic field, thus changing the guided wavelength and phase delay. Semiconductor phase shifters include switched line, loaded line, and switched path designs using PIN diodes or FETs. Digital phase shifters provide precise phase shifts in discrete increments. Phase shifters have applications in communication systems, radar systems, and industrial instrumentation due to their ability to electronically control the phase of RF signals.
Multi-power rail FLR configurable for Digital CircuitsIRJET Journal
This document proposes a multi-power rail configurable fast load regulator (FLR) for digital circuits. The FLR uses dual 1.8V and 3.3V power rails to improve power efficiency by 40% compared to a single 3.3V rail, especially at lower output voltages of 1.0V. The architecture is optimized so that 80% of the current comes from the 1.8V rail at 1.0V output, decreasing as the output voltage increases toward 1.5V. Protection transistors are added to prevent latch-up by ensuring only one power rail is active at a time. Simulation results show the schematic and layout of the proposed FLR.
28 GHz balanced pHEMT VCO with low phase noise and high output power performa...IJECEIAES
This paper presents the study and design of a balanced voltage controlled oscillator VCO for 5G wireless communication systems. This circuit is designed in monolithic microwave integrated circuit (MMIC) technology using PH15 process from UMS foundry. The VCO ensures an adequate tuning range by a single-ended pHEMT varactors configuration. The simulation results show that this circuit delivers a sinusoidal signal of output power around 9 dBm with a second harmonic rejection between 25.87 and 33.83 dB, the oscillation frequency varies between 26.46 and 28.90 GHz, the phase noise is -113.155 and -133.167 dBc/Hz respectively at 1 MHz and 10 MHz offset and the Figure of Merit is -181.06 dBc/Hz. The power consumed by the VCO is 122 mW. The oscillator layout with bias and RF output pads occupies an area of 0.515 mm 2 .
The document describes the design of a low power preamplifier integrated circuit for cochlear implants using a split folded cascode technique. This technique splits the input transistors into two branches with equal aspect ratios, increasing the overall transconductance by 1.414 times compared to a normal folded cascode. Simulations of the proposed preamplifier design in Cadence Virtuoso using a 180nm process show a mid-band gain of 43.7 dB, bandwidth of 18-20 kHz, and input-referred noise of 473.47 nV/√Hz at 4 kHz, while consuming 4.47 μW from a 1.8V supply. The split folded cascode technique enhances performance over normal cascode
The pulse generator which has been implemented in the pulse electric field (PEF) treatment system for food processing is worth to be highlighted and improved. It is parallel with the advancement in semiconductor technology, which offers robust and accurate devices. This research is an effort to produce a low cost, compact and reliable pulse generator as well as equipped with a pulse width modulation (PWM) method for wide selection of frequency and duty cycle. The result shows that the simulation process has proven the theoretical concept to be right and yields the desired outcome based on the designed values. Then, the actual printed circuit board (PCB) has been fabricated to obtain practical results which intended to be compared with the simulation outcomes. Concerning the frequency and its duty cycle, both parameters can be altered without affecting each other. It means by changing the frequency, duty cycle remains the same and vice versa. Thus, this proposed pulse generator achieves its objective and fits to be implemented in PEF treatment technology. It also can replace the conventional pulse forming network (PFN) which is bulky and costly.
In this research, we present a low phase noise (PN) and wide tuning range 175 GHz inductors and capacitors (LC) voltage-controlled oscillator (VCO) based on a differential Colpitts oscillator that was designed using a 0.13 μm bipolar complementary metal oxide semiconductor (BiCMOS) and simulated. The square of the tank Q-factor and the square of the oscillation amplitude were both maximized to reduce PN. With an extensive examination of parasitic, mathematical analysis of load impedances, and implementation of differential design, the PN was reduced, and the output power was enhanced. Using a supply voltage of 1.6 V, the VCO consumes 41.9 mA, resulting in a total power usage of 67 mW to prevent undesirable PN deterioration, an inter-stage LC filter at the VCO-buffer interface increases the swing at the buffer input. To make a better output, a buffer is used to isolate the load from the VCO core. In addition, the VCO has a high linearity and the overall, the VCO presented in this study demonstrates excellent performance and has the potential to be used in a wide range of applications that require a high-performance, low-power VCO.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document summarizes a research paper that presents the design of a novel 5-stage Inductor-less Current Controlled Oscillator (ICCO) using 180nm CMOS technology. The ICCO achieves a peak oscillation frequency of 6.0 GHz with a low phase noise of -115.67 dBc/Hz at a 1MHz offset. This is accomplished through the use of active inductors to replace passive inductors, improving performance while reducing complexity and cost. Simulation results show the ICCO achieves a tuning range of 2.89 GHz. Compared to prior work, the proposed ICCO offers superior phase noise and frequency performance in a smaller layout size.
A Status Data Transmitting System for Vessel MonitoringIJECEIAES
This paper presents a status data transmitting system suitable for vessel monitoring. The system consists of four main parts, which are a frequency synthesizer, a horn antenna, a status data module and a power amplifier. The proposed frequency synthesizer can flexibly change the frequency in a wide range (from 600 MHz to 4.2 GHz) and the output power (from -6 dBm to -3 dBm). By using the phase-locked loop, the synthesizer’s stability over temperature and tolerance are comparable to temperature compensated crystal oscillators (TCXO) that is about +/- 3 ppm. Moreover, phase noise performance of the synthesizer is less than -90 dBc/Hz at 1 KHz and -100 dBc/Hz at 100 KHz. The impedance bandwidth of the horn antenna can be controlled by using the beveling technique. The status data module packs information of the identification, longitude, latitude, and state of the vessel into data frames. FSK/MSK/GMSK schemes were used to modulate the data. The power amplifier provides 130 W output power at S-band. The fundamental characteristics of the implemented transmitter have been measured and verified.
Design of Wide-band Power Amplifier Based on Power Combiner Technique with Lo...IJECEIAES
This document summarizes the design of a wide-band power amplifier with low intermodulation distortion for S-band applications. The amplifier was designed using a power combining technique that divides the wide 2-4 GHz band into two narrow bands that are then recombined. Class A topology and single section quarter wave transformer matching networks were used. Simulation results showed input return loss below -10 dB, gain above 10 dB across the band, stability over the bandwidth, and intermodulation distortion below -50 dBc, meeting design specifications. The amplifier could potentially be used in applications such as satellite communications and wireless networks.
This document describes the VLSI implementation of a fractional-N phase locked loop (PLL) frequency synthesizer using 45nm technology. It discusses the design and simulation of the key PLL components including the phase detector, loop filter, voltage controlled oscillator, and sigma-delta modulator. The layout of the overall fractional-N PLL integrated circuit is presented, which consists of 23 NMOS and 23 PMOS transistors. Simulation results show the PLL locks onto an output frequency of 2.5GHz while consuming only 53.239μwatts of power.
A Novel Design of a Microstrip Microwave Power Amplifier for DCS Application ...IJECEIAES
This paper presents a 1.80GHz class-A Microwave power amplifier (PA). The proposed power amplifier is designed with single-stage architecture. This power amplifier consists of a bipolar transistor and improved by Collector-Feedback Biasing fed with a single power supply. The aim of this work is to improve the performance of this amplifier by using simple stubs with 50Ω microstrip transmissions lines. The proposed PA is investigated and optimized by utilizing Advanced Design System (ADS) software. The simulation results show that the amplifier achieves a high power gain of 13dB, output power rise up to 21dBm and good impedances matching ;For the input reflection coefficient (S11) is below than - 46.39dB. Regarding the output reflection coefficient (S22) is below than -29.898dB, with an overall size of about 93 x 59mm². By the end; we find that this power amplifier offers an excellent performance for DCS applications.
Design and implementation of pll frequency synthesizer using pe3336 ic for ir...elelijjournal
The design and experimental verification of a low phase noise phase locked loop (PLL) frequency synthesizer using Peregrine’s PE83336 IC is presented. This PLL is used as frequency synthesizer which generates stable and low phase noise signal for space applications. A stable reference frequency of 22.8MHz is provided to the PLL through a temperature compensated crystal oscillator (TCXO). Experimental results of the PLL frequency synthesizer shows the excellent performance achieved at Xband. The PLL model implemented with frequency resolution of 5.8MHz, and phase noise better than -
81dBc/Hz @ 1 kHz offset at X-band. The complete model is fabricated on RT-duroid 6010 substrate
Design of 5.1 GHz ultra-low power and wide tuning range hybrid oscillatorIJECEIAES
The objective of the proposed work is to demonstrate the use of a hybrid approach for the design of a voltage-controlled oscillator (VCO) which can lead to higher performance. The performance is improved in terms of the tuning range, frequency of oscillation, voltage swing, and power consumption. The proposed hybrid VCO is designed using an active load common source amplifier and current starved inverter that are cascaded alternatively to achieve low power consumption. The proposed VCO achieves a measured phase noise of -74 dBc/Hz and a figure of merit (FOM) of -152.6 dBc/Hz at a 1 MHz offset when running at 5.1 GHz frequency. The hybrid current starved-current starved VCO (CS-CS VCO) consumes a power of 289 µW using a 1.8 V supply and attains a wide tuning range of 96.98%. Hybrid VCO is designed using 0.09 µm complementary metal– oxide–semiconductor (CMOS) technology. To justify the robustness, reliability, and scalability of the circuit different corner analysis is performed through 500 runs of Monte-Carlo simulation.
A miniature tunable quadrature shadow oscillator with orthogonal control IJECEIAES
This article presents a new design of a quadrature shadow oscillator. The oscillator is realized using one input and two outputs of a second-order filter cell together with external amplifiers in a feedback configuration. The oscillation characteristics are controlled via the external gain without disturbing the internal filter cell, following the concept of the shadow oscillator. The proposed circuit configuration is simple with a small component-count. It consists of, two voltage-different transconductance amplifiers (VDTAs) along with a couple of passive elements. The frequency of oscillation (FO) and the condition of oscillation (CO) are controlled orthogonally via the dc bias current and external gain. Moreover, with the addition of the external gain, the frequency range of oscillation can be further extended. The proposed work is verified by computer simulation with the use of 180 nm complementary metal–oxide–semiconductor (CMOS) model parameters. The simulation gives satisfactory results of two sinusoidal output signals in quadrature with some small total harmonic distortions (THD). In addition, a circuit experiment is performed using the commercial operational transconductance amplifiers LM13700 as the active components. The circuit experiment also demonstrates satisfactory outcome which confirms the validity of the proposed circuit.
This document presents the design of a high performance folded cascade OTA and sample and hold circuit. The OTA is designed to achieve 10-bit resolution while operating at a 28 MHz sampling frequency. Simulation results show the OTA achieves a high open loop gain of 72 dB and bandwidth of 112 MHz, with a phase margin of 73 degrees. A low resistance transmission gate switch is designed to reduce charge injection and clock feedthrough effects during sampling. The circuit is implemented in a 130 nm CMOS technology.
This study analyzed optimization of wireless power transfer using a half-bridge flyback converter. The researchers designed a protection circuit to maintain the resonant frequency as the load changed. Experiments showed wireless power transfer of over 3.4W and 61% efficiency to a variable LED load. Adding the protection circuit produced more stable output than without it by preventing changes in resonant frequency from load variations.
Designing an Antenna System That Can Perform Conditional RF to DC Harnessing ...IOSRJECE
Electromagnetic energy or RF energy will play a pivotal role in wireless technology and wireless communication in the impending future. The paper proposes a concept for a patch antenna based system that can harness RF energy upon triggering and can convert the harnessed RF to DC from the radio frequency of 1 GHz to 3 GHz, the design frequency is 2.4GHz. The patch antenna system contains a high gain patch antenna along with a wireless communicating module and a conversion circuit. The return loss of the antenna is approximately 27.1dB. The power gain is 30.1 dBm .The converter circuit is designed in), Multi-Sim to get an output voltage of around 5V that can be used to power a mobile-device or maybe stored in a battery. The triggering part is done with the help of a T-mote which is simulated in a network simulator, Cooja. The patch antenna is simulated in High Frequency Structural Simulator
Development of Class D Inverter for Acoustics Energy Transfer Implantable Dev...IJPEDS-IAES
The working principle of half-bridge Class D Parallel-Resonant Inverter
(PRI) as power amplifier is presented in this paper. Simulation of the model
is carried out using Proteus. In order to verify the simulation results, an
experimental verification is done. This inverter used to excite PZT
transducers at suggested resonant frequency of 416 kHz with power level
transferred through Acoustics Energy Transfer (AET) concept at about 80
mW. As experimental outcome result, the system managed to transfer energyof 66 mW to the receiver side.
Integrated sub-harmonically pumped up-converter antenna for spatial power com...fanfan he
This document describes the design and measurement of an integrated sub-harmonically pumped up-converter antenna array for spatial power combining. Key points:
1) A Ka-band up-converter using a substrate integrated waveguide bandpass filter is designed with a conversion loss of around 7 dB.
2) An integrated up-converter antenna element is designed by combining the up-converter with a substrate integrated waveguide fed antipodal linearly tapered slot antenna.
3) A 2x2 array of the integrated up-converter antennas is fabricated and measured to have a power combining efficiency above 90% and third order intercept point EIRP of 16 dBm, showing its potential as a low-cost transmitter.
IRJET- Wireless RF Energy Harvesting using Inverted F AntennaIRJET Journal
This document describes a project to develop a wireless RF energy harvesting system using an inverted F antenna. Key points:
- An array of 20 inverted F antennas will be used to harvest RF energy from surrounding wireless devices like mobile phones and WiFi routers.
- The antennas will capture RF signals and convert them to AC which will then be rectified to DC using Schottky diodes.
- The DC output will be stored in a supercapacitor and can then be used to charge batteries for low-power applications.
- Simulation software HFSS was used to design and optimize the inverted F antenna, achieving a maximum gain of 3.1 dB. PCB design software KiCad was used to lay
LOW POWER SI CLASS E POWER AMPLIFIER AND RF SWITCH FOR HEALTH CAREieijjournal1
This research was to design a 2.4 GHz class E Power Amplifier (PA) for health care, with 0.18um
Semiconductor Manufacturing International Corporation CMOS technology by using Cadence software.
And also RF switch was designed at cadence software with power Jazz 180nm SOI process. The ultimate
goal for such application is to reach high performance and low cost, and between high performance and
low power consumption design. This paper introduces the design of a 2.4GHz class E power amplifier and
RF switch design. PA consists of cascade stage with negative capacitance. This power amplifier can
transmit 16dBm output power to a 50Ω load. The performance of the power amplifier and switch meet the
specification requirements of the desired.
Similar to A Novel Design of Voltage Controlled Oscillator by Using the Method of Negative Resistance (20)
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Neural network optimizer of proportional-integral-differential controller par...IJECEIAES
Wide application of proportional-integral-differential (PID)-regulator in industry requires constant improvement of methods of its parameters adjustment. The paper deals with the issues of optimization of PID-regulator parameters with the use of neural network technology methods. A methodology for choosing the architecture (structure) of neural network optimizer is proposed, which consists in determining the number of layers, the number of neurons in each layer, as well as the form and type of activation function. Algorithms of neural network training based on the application of the method of minimizing the mismatch between the regulated value and the target value are developed. The method of back propagation of gradients is proposed to select the optimal training rate of neurons of the neural network. The neural network optimizer, which is a superstructure of the linear PID controller, allows increasing the regulation accuracy from 0.23 to 0.09, thus reducing the power consumption from 65% to 53%. The results of the conducted experiments allow us to conclude that the created neural superstructure may well become a prototype of an automatic voltage regulator (AVR)-type industrial controller for tuning the parameters of the PID controller.
An improved modulation technique suitable for a three level flying capacitor ...IJECEIAES
This research paper introduces an innovative modulation technique for controlling a 3-level flying capacitor multilevel inverter (FCMLI), aiming to streamline the modulation process in contrast to conventional methods. The proposed
simplified modulation technique paves the way for more straightforward and
efficient control of multilevel inverters, enabling their widespread adoption and
integration into modern power electronic systems. Through the amalgamation of
sinusoidal pulse width modulation (SPWM) with a high-frequency square wave
pulse, this controlling technique attains energy equilibrium across the coupling
capacitor. The modulation scheme incorporates a simplified switching pattern
and a decreased count of voltage references, thereby simplifying the control
algorithm.
A review on features and methods of potential fishing zoneIJECEIAES
This review focuses on the importance of identifying potential fishing zones in seawater for sustainable fishing practices. It explores features like sea surface temperature (SST) and sea surface height (SSH), along with classification methods such as classifiers. The features like SST, SSH, and different classifiers used to classify the data, have been figured out in this review study. This study underscores the importance of examining potential fishing zones using advanced analytical techniques. It thoroughly explores the methodologies employed by researchers, covering both past and current approaches. The examination centers on data characteristics and the application of classification algorithms for classification of potential fishing zones. Furthermore, the prediction of potential fishing zones relies significantly on the effectiveness of classification algorithms. Previous research has assessed the performance of models like support vector machines, naïve Bayes, and artificial neural networks (ANN). In the previous result, the results of support vector machine (SVM) were 97.6% more accurate than naive Bayes's 94.2% to classify test data for fisheries classification. By considering the recent works in this area, several recommendations for future works are presented to further improve the performance of the potential fishing zone models, which is important to the fisheries community.
Electrical signal interference minimization using appropriate core material f...IJECEIAES
As demand for smaller, quicker, and more powerful devices rises, Moore's law is strictly followed. The industry has worked hard to make little devices that boost productivity. The goal is to optimize device density. Scientists are reducing connection delays to improve circuit performance. This helped them understand three-dimensional integrated circuit (3D IC) concepts, which stack active devices and create vertical connections to diminish latency and lower interconnects. Electrical involvement is a big worry with 3D integrates circuits. Researchers have developed and tested through silicon via (TSV) and substrates to decrease electrical wave involvement. This study illustrates a novel noise coupling reduction method using several electrical involvement models. A 22% drop in electrical involvement from wave-carrying to victim TSVs introduces this new paradigm and improves system performance even at higher THz frequencies.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Bibliometric analysis highlighting the role of women in addressing climate ch...IJECEIAES
Fossil fuel consumption increased quickly, contributing to climate change
that is evident in unusual flooding and draughts, and global warming. Over
the past ten years, women's involvement in society has grown dramatically,
and they succeeded in playing a noticeable role in reducing climate change.
A bibliometric analysis of data from the last ten years has been carried out to
examine the role of women in addressing the climate change. The analysis's
findings discussed the relevant to the sustainable development goals (SDGs),
particularly SDG 7 and SDG 13. The results considered contributions made
by women in the various sectors while taking geographic dispersion into
account. The bibliometric analysis delves into topics including women's
leadership in environmental groups, their involvement in policymaking, their
contributions to sustainable development projects, and the influence of
gender diversity on attempts to mitigate climate change. This study's results
highlight how women have influenced policies and actions related to climate
change, point out areas of research deficiency and recommendations on how
to increase role of the women in addressing the climate change and
achieving sustainability. To achieve more successful results, this initiative
aims to highlight the significance of gender equality and encourage
inclusivity in climate change decision-making processes.
Voltage and frequency control of microgrid in presence of micro-turbine inter...IJECEIAES
The active and reactive load changes have a significant impact on voltage
and frequency. In this paper, in order to stabilize the microgrid (MG) against
load variations in islanding mode, the active and reactive power of all
distributed generators (DGs), including energy storage (battery), diesel
generator, and micro-turbine, are controlled. The micro-turbine generator is
connected to MG through a three-phase to three-phase matrix converter, and
the droop control method is applied for controlling the voltage and
frequency of MG. In addition, a method is introduced for voltage and
frequency control of micro-turbines in the transition state from gridconnected mode to islanding mode. A novel switching strategy of the matrix
converter is used for converting the high-frequency output voltage of the
micro-turbine to the grid-side frequency of the utility system. Moreover,
using the switching strategy, the low-order harmonics in the output current
and voltage are not produced, and consequently, the size of the output filter
would be reduced. In fact, the suggested control strategy is load-independent
and has no frequency conversion restrictions. The proposed approach for
voltage and frequency regulation demonstrates exceptional performance and
favorable response across various load alteration scenarios. The suggested
strategy is examined in several scenarios in the MG test systems, and the
simulation results are addressed.
Enhancing battery system identification: nonlinear autoregressive modeling fo...IJECEIAES
Precisely characterizing Li-ion batteries is essential for optimizing their
performance, enhancing safety, and prolonging their lifespan across various
applications, such as electric vehicles and renewable energy systems. This
article introduces an innovative nonlinear methodology for system
identification of a Li-ion battery, employing a nonlinear autoregressive with
exogenous inputs (NARX) model. The proposed approach integrates the
benefits of nonlinear modeling with the adaptability of the NARX structure,
facilitating a more comprehensive representation of the intricate
electrochemical processes within the battery. Experimental data collected
from a Li-ion battery operating under diverse scenarios are employed to
validate the effectiveness of the proposed methodology. The identified
NARX model exhibits superior accuracy in predicting the battery's behavior
compared to traditional linear models. This study underscores the
importance of accounting for nonlinearities in battery modeling, providing
insights into the intricate relationships between state-of-charge, voltage, and
current under dynamic conditions.
Smart grid deployment: from a bibliometric analysis to a surveyIJECEIAES
Smart grids are one of the last decades' innovations in electrical energy.
They bring relevant advantages compared to the traditional grid and
significant interest from the research community. Assessing the field's
evolution is essential to propose guidelines for facing new and future smart
grid challenges. In addition, knowing the main technologies involved in the
deployment of smart grids (SGs) is important to highlight possible
shortcomings that can be mitigated by developing new tools. This paper
contributes to the research trends mentioned above by focusing on two
objectives. First, a bibliometric analysis is presented to give an overview of
the current research level about smart grid deployment. Second, a survey of
the main technological approaches used for smart grid implementation and
their contributions are highlighted. To that effect, we searched the Web of
Science (WoS), and the Scopus databases. We obtained 5,663 documents
from WoS and 7,215 from Scopus on smart grid implementation or
deployment. With the extraction limitation in the Scopus database, 5,872 of
the 7,215 documents were extracted using a multi-step process. These two
datasets have been analyzed using a bibliometric tool called bibliometrix.
The main outputs are presented with some recommendations for future
research.
Use of analytical hierarchy process for selecting and prioritizing islanding ...IJECEIAES
One of the problems that are associated to power systems is islanding
condition, which must be rapidly and properly detected to prevent any
negative consequences on the system's protection, stability, and security.
This paper offers a thorough overview of several islanding detection
strategies, which are divided into two categories: classic approaches,
including local and remote approaches, and modern techniques, including
techniques based on signal processing and computational intelligence.
Additionally, each approach is compared and assessed based on several
factors, including implementation costs, non-detected zones, declining
power quality, and response times using the analytical hierarchy process
(AHP). The multi-criteria decision-making analysis shows that the overall
weight of passive methods (24.7%), active methods (7.8%), hybrid methods
(5.6%), remote methods (14.5%), signal processing-based methods (26.6%),
and computational intelligent-based methods (20.8%) based on the
comparison of all criteria together. Thus, it can be seen from the total weight
that hybrid approaches are the least suitable to be chosen, while signal
processing-based methods are the most appropriate islanding detection
method to be selected and implemented in power system with respect to the
aforementioned factors. Using Expert Choice software, the proposed
hierarchy model is studied and examined.
Enhancing of single-stage grid-connected photovoltaic system using fuzzy logi...IJECEIAES
The power generated by photovoltaic (PV) systems is influenced by
environmental factors. This variability hampers the control and utilization of
solar cells' peak output. In this study, a single-stage grid-connected PV
system is designed to enhance power quality. Our approach employs fuzzy
logic in the direct power control (DPC) of a three-phase voltage source
inverter (VSI), enabling seamless integration of the PV connected to the
grid. Additionally, a fuzzy logic-based maximum power point tracking
(MPPT) controller is adopted, which outperforms traditional methods like
incremental conductance (INC) in enhancing solar cell efficiency and
minimizing the response time. Moreover, the inverter's real-time active and
reactive power is directly managed to achieve a unity power factor (UPF).
The system's performance is assessed through MATLAB/Simulink
implementation, showing marked improvement over conventional methods,
particularly in steady-state and varying weather conditions. For solar
irradiances of 500 and 1,000 W/m2
, the results show that the proposed
method reduces the total harmonic distortion (THD) of the injected current
to the grid by approximately 46% and 38% compared to conventional
methods, respectively. Furthermore, we compare the simulation results with
IEEE standards to evaluate the system's grid compatibility.
Enhancing photovoltaic system maximum power point tracking with fuzzy logic-b...IJECEIAES
Photovoltaic systems have emerged as a promising energy resource that
caters to the future needs of society, owing to their renewable, inexhaustible,
and cost-free nature. The power output of these systems relies on solar cell
radiation and temperature. In order to mitigate the dependence on
atmospheric conditions and enhance power tracking, a conventional
approach has been improved by integrating various methods. To optimize
the generation of electricity from solar systems, the maximum power point
tracking (MPPT) technique is employed. To overcome limitations such as
steady-state voltage oscillations and improve transient response, two
traditional MPPT methods, namely fuzzy logic controller (FLC) and perturb
and observe (P&O), have been modified. This research paper aims to
simulate and validate the step size of the proposed modified P&O and FLC
techniques within the MPPT algorithm using MATLAB/Simulink for
efficient power tracking in photovoltaic systems.
Adaptive synchronous sliding control for a robot manipulator based on neural ...IJECEIAES
Robot manipulators have become important equipment in production lines, medical fields, and transportation. Improving the quality of trajectory tracking for
robot hands is always an attractive topic in the research community. This is a
challenging problem because robot manipulators are complex nonlinear systems
and are often subject to fluctuations in loads and external disturbances. This
article proposes an adaptive synchronous sliding control scheme to improve trajectory tracking performance for a robot manipulator. The proposed controller
ensures that the positions of the joints track the desired trajectory, synchronize
the errors, and significantly reduces chattering. First, the synchronous tracking
errors and synchronous sliding surfaces are presented. Second, the synchronous
tracking error dynamics are determined. Third, a robust adaptive control law is
designed,the unknown components of the model are estimated online by the neural network, and the parameters of the switching elements are selected by fuzzy
logic. The built algorithm ensures that the tracking and approximation errors
are ultimately uniformly bounded (UUB). Finally, the effectiveness of the constructed algorithm is demonstrated through simulation and experimental results.
Simulation and experimental results show that the proposed controller is effective with small synchronous tracking errors, and the chattering phenomenon is
significantly reduced.
Remote field-programmable gate array laboratory for signal acquisition and de...IJECEIAES
A remote laboratory utilizing field-programmable gate array (FPGA) technologies enhances students’ learning experience anywhere and anytime in embedded system design. Existing remote laboratories prioritize hardware access and visual feedback for observing board behavior after programming, neglecting comprehensive debugging tools to resolve errors that require internal signal acquisition. This paper proposes a novel remote embeddedsystem design approach targeting FPGA technologies that are fully interactive via a web-based platform. Our solution provides FPGA board access and debugging capabilities beyond the visual feedback provided by existing remote laboratories. We implemented a lab module that allows users to seamlessly incorporate into their FPGA design. The module minimizes hardware resource utilization while enabling the acquisition of a large number of data samples from the signal during the experiments by adaptively compressing the signal prior to data transmission. The results demonstrate an average compression ratio of 2.90 across three benchmark signals, indicating efficient signal acquisition and effective debugging and analysis. This method allows users to acquire more data samples than conventional methods. The proposed lab allows students to remotely test and debug their designs, bridging the gap between theory and practice in embedded system design.
Detecting and resolving feature envy through automated machine learning and m...IJECEIAES
Efficiently identifying and resolving code smells enhances software project quality. This paper presents a novel solution, utilizing automated machine learning (AutoML) techniques, to detect code smells and apply move method refactoring. By evaluating code metrics before and after refactoring, we assessed its impact on coupling, complexity, and cohesion. Key contributions of this research include a unique dataset for code smell classification and the development of models using AutoGluon for optimal performance. Furthermore, the study identifies the top 20 influential features in classifying feature envy, a well-known code smell, stemming from excessive reliance on external classes. We also explored how move method refactoring addresses feature envy, revealing reduced coupling and complexity, and improved cohesion, ultimately enhancing code quality. In summary, this research offers an empirical, data-driven approach, integrating AutoML and move method refactoring to optimize software project quality. Insights gained shed light on the benefits of refactoring on code quality and the significance of specific features in detecting feature envy. Future research can expand to explore additional refactoring techniques and a broader range of code metrics, advancing software engineering practices and standards.
Smart monitoring technique for solar cell systems using internet of things ba...IJECEIAES
Rapidly and remotely monitoring and receiving the solar cell systems status parameters, solar irradiance, temperature, and humidity, are critical issues in enhancement their efficiency. Hence, in the present article an improved smart prototype of internet of things (IoT) technique based on embedded system through NodeMCU ESP8266 (ESP-12E) was carried out experimentally. Three different regions at Egypt; Luxor, Cairo, and El-Beheira cities were chosen to study their solar irradiance profile, temperature, and humidity by the proposed IoT system. The monitoring data of solar irradiance, temperature, and humidity were live visualized directly by Ubidots through hypertext transfer protocol (HTTP) protocol. The measured solar power radiation in Luxor, Cairo, and El-Beheira ranged between 216-1000, 245-958, and 187-692 W/m 2 respectively during the solar day. The accuracy and rapidity of obtaining monitoring results using the proposed IoT system made it a strong candidate for application in monitoring solar cell systems. On the other hand, the obtained solar power radiation results of the three considered regions strongly candidate Luxor and Cairo as suitable places to build up a solar cells system station rather than El-Beheira.
An efficient security framework for intrusion detection and prevention in int...IJECEIAES
Over the past few years, the internet of things (IoT) has advanced to connect billions of smart devices to improve quality of life. However, anomalies or malicious intrusions pose several security loopholes, leading to performance degradation and threat to data security in IoT operations. Thereby, IoT security systems must keep an eye on and restrict unwanted events from occurring in the IoT network. Recently, various technical solutions based on machine learning (ML) models have been derived towards identifying and restricting unwanted events in IoT. However, most ML-based approaches are prone to miss-classification due to inappropriate feature selection. Additionally, most ML approaches applied to intrusion detection and prevention consider supervised learning, which requires a large amount of labeled data to be trained. Consequently, such complex datasets are impossible to source in a large network like IoT. To address this problem, this proposed study introduces an efficient learning mechanism to strengthen the IoT security aspects. The proposed algorithm incorporates supervised and unsupervised approaches to improve the learning models for intrusion detection and mitigation. Compared with the related works, the experimental outcome shows that the model performs well in a benchmark dataset. It accomplishes an improved detection accuracy of approximately 99.21%.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEMHODECEDSIET
Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
2. Int J Elec & Comp Eng ISSN: 2088-8708
A Novel Design of Voltage Controlled Oscillator By using the Method of Negative Resistance (Ayoub Malki)
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Voltage controlled oscillator are actually very important and indispensable module in the design of
communication system employing in microwave technology. The objective’s design is to get very stable
output signal controlled in frequency with very low phase noise, power management (consumption, output
power), pulling, matching impedance and the rejection of unwanted frequency bands. The role of the VCO is
to provide approximately very perfect signal to the antenna to avoid the use of very high gain amplifier and
the use of filters to bloc undesirable frequencies. Also the noise generates into the output signal of the VCO
is susceptible strongly to degrade the sensitivity of the communication system. This noise called phase noise
is distributed around the main frequency. In the other hand, in addition to the difficulty of VCO designs , the
technological tendency, the requirements of the regulations and the speed of development of the
telecommunications have increasingly forced to fabricate voltage controlled oscillator with very precise
performances in term of size, consumption, phase noise, stability and output power. For that we present in
this work, the study and complete design of a low phase noise voltage controlled oscillator, operating at
[480MHz; 1.4GHz] on epoxy FR4 with performances more better than founded in the literature.
We begin by presenting the oscillator theory including the fundamental oscillations conditions, the
negative resistance structures and the hybrid integrated voltage controlled oscillator specifications. The
choice of the topology is then argued. The last part of this work relates to the design process up to the
fabrication and testing of our VCO. The importance of the layout realization step is widely developed. It
allowed to proose an optimized and original architecture. The presentation and analysis of the obtained
results with the published results in the literature positively end this work [3].
2. FIXED FREQUENCY OSCILLATOR DESIGN
In this paper, before to design voltage controlled oscillator with known tuning bandwidth we
propose firstly to design an oscillator at fixed frequency to acquire the high performance of our oscillator.
Secondly we replace the resonator of the fixed frequency oscillator by model of varactor based on diode to
allow us to control the frequency of the voltage controlled oscillator.
An oscillator consist generally of four independent parts: matching network, active element
(amplifier), resonator and bias network feedback element. During the procedure design, to improve the
characteristic of the proposed model each component must be analyzed separately (choice of transistor,
choice of positioning of tuning element, bias design and the architecture of the resonator). Finally the study
of the interactive behaviors between the different components of oscillator is very important during the
procedure design because this step allow us to get very precise performance of our structure [4].
The theory of oscillators can be firstly approached by the modeling of a counter-reacted system
which is none other than the transmission approach shown in Figure 1(a). A non-linear amplifier with
transfer function G is responsible for supplying the power to the load, it is then associated in the oscillator
loop with a selective transfer function filter β (f). It is therefore a positive feedback that reinjects part of the
output signal at the input of the amplifier to build the oscillation [5]-[6].
(a) (b)
Figure 1. Oscillator as (a) feedback loop (b) negative resistance.
A sustained oscillation in steady state, requires that two conditions, known as the Barkhausen
criterion, be simultaneously satisfied. Such a looped system reaches its stable oscillation state when the
closed loop transfer function is exactly equal to 1 [7]. This implies that the total phase shift on a loop turn is
zero. Mathematically the Barkhausen criterion can be written as follows:
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║β(f0)*G║=1 (1)
Φ(β(f0)*G)=0 (2)
Although the model shown in Figure 1 (a) can be used to analyze and determine the necessary and
sufficient conditions for oscillation, it is more judicious in the case of the design of VCO, to use the model
shown in Figure 1 (b) whose analysis is performed using the concept of negative resistance. This concept
explains that the tuned circuit, once it is supplied with voltage, will oscillate continuously if there is active
device to compensate the resistance that absorb energy. The function of the amplifier therefore has the role of
producing the negative resistance necessary to maintain the oscillation, ensuring a quantity of energy equal to
that absorbed [8].
The energy in an oscillator is inevitably dissipated due to the non-ideality of the circuit elements.
Therefore, energy must be used to maintain the oscillation. This can be achieved with the resulting negative
resistance of transistor created by the transconductance g of transistor. For this study, an ultra-low noise SiGe
transistor from Infineon, the BFP740, was chosen. Infineon BFP740 is a general purpose transistor that offers
excellent performance at high frequency. The BFP740 is housed in a low cost low parasitic 3 lead F59. This
transistor is recommended by Infineon to fabricate low-noise microwave oscillators or amplifiers and it
delivers outstanding performance for a wide range of wireless application up to frequencies of 12 GHz. Its
transition frequency is given at 150 GHz and it has a ultra-low noise figure.
At the start of an oscillator the noise existing inside each electrical component must be excited to
produce output signal. This excitation is the result of the negative energy created by the transistor. For the
transistor deliver a sufficient amount of negative energy, it must be sufficiently unstable when the power
source is connected to the system. This instability is translated by the module of return loss greater than the
unit in the input port (|S11|˃) and the stability factor less than the unit (|K|˂1). It’s necessary that both ports of
the amplifier are unstable because both sides of the amplifier serve a particular purpose in the built up of
oscillation.
𝑲 =
𝟏−|𝑺 𝟏𝟏| 𝟐−|𝑺 𝟐𝟐| 𝟐+|𝑺 𝟏𝟏 𝑺 𝟐𝟐−𝑺 𝟏𝟐 𝑺 𝟐𝟏| 𝟐
𝟐|𝑺 𝟐𝟏 𝑺 𝟏𝟐|
Based on the scattering parameters of BFP740 at common base given by the manufacturer Infineon
at 1 GHz, we can conclude that the transistor operates at the stable area. In order to make it unstable we have
added a feedback element. So by optimization of these feedback elements parameters and the adjustments of
polarization parameters the transistor is becoming unstable.
The study of the active device stability in the common base configuration can be discussed using the
ADS simulation specially the tool Stabfact to get the stability factor k. This method consist to change the
frequency around the frequency of oscillation sitting in the S-parameters component (start=0.4 GHz and
stop= 1.4 GHz). The resulting k factor versus frequency is shown in Table.1. The active device in a common
base configuration with the feedback element are potentially unstable at [480MHz; 1.4GHz] [9].
Table 1. K Factor for Tte Active Device
Frequency Sabfact:K
400MHz -0.81
700 MHz -0.82
900MHz -0.84
1.1GHz -0.82
1.4GHz -0.79
The bias of the transistor is provided by a resistor bridge R1, R2 and a collector supply voltage of 5v.
A very detailed study is brought to see the different bias parameters because it plays a very important role to
achieve the performances of our oscillator in term of power, efficient and phase noise. In this study we tried
to have a stable transistor operation point and to minimize the power consummation because the
characteristics of our transistor depend directly on its polarization [10].
An important issue in the design of a high performance oscillator is the design of a high quality
resonator. As we have indicated, the quality factor has a significant impact on the performance of phase
noise. It is therefore important to choose the high quality resonator in order to meet the best specifications.
The chosen resonator is a micro strip resonator of length λ/2. The circuit being in hybrid technology, the
surface stress is much less than with an integrated circuit. The use of this type of resonator improves
4. Int J Elec & Comp Eng ISSN: 2088-8708
A Novel Design of Voltage Controlled Oscillator By using the Method of Negative Resistance (Ayoub Malki)
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oscillator specifications better than LC resonator in terms of size and noise. The aim is to have inductance
and capacitance where one can store energy without loss and at the same time the ability to integrate with a
varactor. The quality factor of this micro strip resonator can be defined as follows:
Q =
w0
∆w
(4)
Q = 2π
Energie stokée
Energie liberée par cycle
(5)
At frequencies near of resonance frequency, the microstrip line can be replaced by an RLC series circuit
whose values can be estimated using the following relationship:
Ls =
Q Rs
w0
(6)
Cs =
1
Q Rsw0
(7)
RS the series resistance determined by the actual part of the input impedance of the resonator at
resonance, W0 is the pulsation at resonance, Ls inductance component of the resonator and CS capacitance
component of the resonator. To reduce the series resistance of the resonator we tried the maximum possible
to reduce the width of micro strip lines. So a minimum characteristic impedance chosen is 25.
The last step in this work is to design matching impedance. Impedance matching is a technique used
in electricity to optimize the transfer of electrical power between a transmitter (source) and an electrical
receiver (load) 1 and optimize the transmission of telecommunications signals.the theory of maximum power
determines that the impedance of the load must be the conjugate complex of the impedance of the generator;
Now the whole circuit including the active device with its polarization, resonator and matching impedance is
as in Figure 2.
Figure 2. The schematic of the negative resistance microwave oscillator.
For the simulating of the obtained oscillator we can use the harmonic balance used for nonlinear
structure which is frequency domain analysis tool. The frequency spectrum, the steady state and the phase
noise results are shown successively in Figure 3 (a), Figure 3 (b) and Figure 3(c).
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(a) (b)
(c)
Figure 3. Simulated result of fixed oscillator in (a) time domaine (b) frequency domaine (c) phase noise.
It is seen from Figure 3 (a) that the waveform of the output signal is purely sinusoidal at 1 GHz.
The output power at the fundamental frequency is 14.909 dBm as shown in Figure 3 (b). We can also observe
that the power of the harmonics is very negligible compared to the fundamental we can also observe that the
power of the harmonics is very negligible compared to the fundamental one. Which further improves the
distortion of the oscillator. In the author hand the phase noise prediction of the microwave oscillator is 117.6
dBc/Hz.
The proposed voltage controlled oscillator performances were compared to some existing works in
the literature in terms of phase noise, output power and distortion, the comparison results conducts to the best
results. Generally, in the literature, the best results are about -110dBc/hz from 100 Hz of the carrier in term of
phase noise and 7dBm in term of output power. If we compare theses values with reached values in our work
(phase noise: -117.6 dBc at 100 Hz from carrier; output power: 14.909 dBm and the harmonic about -8.42
dBm), we can conclude that the proposed VCO has excellent performances compared to the reported works.
3. VOLTAGE CONTROLLED OSCILLATOR DESIGN
In the following section the design of voltage controlled oscillator is given. This design example
will use the same structure used in the fixed frequency version but we try to replace the resonator by varactor.
The objective of this step is the frequency variation of the fixed frequency oscillator. This is allowed when
the resonator parameters can be modified, namely its inductance and capacitance. There are many methods,
each has their advantages and disadvantages. An integration of varicap based on diode is very adequate to our
structure. The varactor diode, also called varicap diode, reverse polarized will have a variable capacitance
between these two terminals.
In order to choose a suitable varactor for the design, we have to decide on the tuning bandwidth.
This particular requirement is for a tuning bandwidth 45 MHz/V over the tuning range of 1 to 20V. To give
6. Int J Elec & Comp Eng ISSN: 2088-8708
A Novel Design of Voltage Controlled Oscillator By using the Method of Negative Resistance (Ayoub Malki)
4501
us some margin to cover the external parasite effects we choose a bandwidth of 50MHz/V. The varactor
should have a minimum of parasitism, so we opt for a SMT device. The simulation of the complete circuit
with the varactor was run and re-run for each value of the voltage from 1V to 20V. The results of variation
voltage versus frequency and output power are given in Table 2.
Table 2. Tuning Frequency of VCO in Function of Voltage
Voltage Frequency
0.5V 500MHz
5V 700 MHz
10V 900MHz
15V 1.1GHz
20V 1.4GHz
4. EXPERIMENTAL RESULTS AND DISCUSSION
Good isolation between components as well as satisfactory decoupling between the DC ports and
the RF lines are critical considerations for achieving an RF or microwave design. To avoid introducing
asymmetry into the oscillation waveforms and to induce additional phase noise on the output signal,
particular attention must be given to the symmetry of the complete layout. The voltage controlled oscillator
was fabricated on the epoxy substrate with the dielectric constant of 4.4, the metal thickness of 0.035 mm,
and height is 1.60 mm; as hybrid microwave integrated circuit structure. All the circuit components are in
SMD (Surface Mount Device) package. Figure 4 illustrates the photograph of the completed fabricated
voltage controlled oscillator. It occupies a surface of 28*30mm2
integrating the pads of power supplies.
Before the realization of the circuit, the electrical diagram extracted from the final layout, was simulated for
the last time taking into account the given minimum and maximum values of the critical components
(inductance, varactor, capacitances).
Figure 4. Photograph of the fabricated voltage controlled oscillator
The fabriquated voltage controlled oscillator is characterized succevelly in time domaine, frequency
domain and phase noise using Tektronix DPO 7245 digital phosphor oscilloscope, Agilent E4440A PSA
spectrum analyzer and Agilent 5505A. Figure 5 (b) shows that The VCO delivers 12.62dbm at 1 GHz,
Figure5(c) shows that phase noise levels of output signal is -108 dBc/Hz at 100 Hz at an oscillation
frequency of 1 GHz and from Figure 5 (a) The output voltage has ideal sinusoidal shape with peak to peak
voltage swing of 2.6V.
The measured and simulated parameters of our voltage controlled oscillator present approximately
the same results in term of tuning bandwidth, frequency and output power and some offset in phase noise
(9dBc). This offset between measured and simulated phase noise is normal due to the fabrication,
approximations taken by ADS especially phase noise, the quality of components and the integration of the
varicap.
If we compared the obtained results of this work (phase noise -108 dBc/hz , tuning bandwith 920
MHz) with the published results of some scientific reports on microwave oscillator designs [11]-[17], we can
conclude that this voltage controlled oscillator has good results in term of tuning bandwith, phase noise, good
output power and frequency accuracy. These results were the product of deep study of each parameter of the
voltage controlled oscillator and especially the interaction between these parametres.
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(a) (b)
(c)
Figure 5. Measurement result of VCO in (a) time domaine (b) frequency domaine (c) phase noise.
5. CONCLUSION
As a conclusion, we can deduce that we have developed a novel structure negative resistance
voltage controlled oscillator at 480 MHz with tuning bandwith 920 MHz. The fabricated voltage controlled
oscillator produces sinusoidal signal in frequency range [480MHz; 1.4GHz] with start frequency of 480MHz,
output power at 1GHz equal to 12.62dBm, phase noise of the output signal around -108dBc/Hz at 100 Hz.
This work has been designed and adjusted by using a theoretical step and optimization tools applied on active
device, Bias networks, matching impedance and resonator with its varicap,. The comparative study of this
voltage controlled oscillator design with some summary of some scientific reports on voltage controlled
microwave oscillator designs shows that we got better results.
REFERENCES
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A Novel Design of Voltage Controlled Oscillator By using the Method of Negative Resistance (Ayoub Malki)
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BIOGRAPHIES OF AUTHORS
Ayoub Malki was born in Settat, Morocco, In january 1988. He received the master degree in
aeronautic and telecommunications from Air royal scool, University of kadi Aayad Marrakech,
Morocco. He is currently working toward the Ph.D. degree in physics and engineering sciences
at Faculty of Sciences and Technologies, Settat, Morocco. His research interests include the
analysis and design of hybrid, monolithic active and passive microwave electronic circuits.
Larbi El Abdellaoui was born in Tiflet, Morocco, in 1961. He received the Ph.D. degree in
electronics from the University of Metz, in 1994, France. He is currently an associate Professor
of Electronics in Faculty of sciences and techniques, University Hassan 1st, Settat, Morocco. He
is involved in the design of hybrid, monolithic active and passive microwave electronic circuits.
Jamal Zbitou was born in Fes, Morocco, in June 1976. He received the Ph.D. degree in
electronics from Polytech of Nantes, the University of Nantes, Nantes, France, in 2005. He is
currently an associate Professor of Electronics in FST, University Hassan 1st, Settat, Morocco
and the head of Computing Networks and telecommunication in LMEET Laboratory in FSTS.
He is involved in the design of hybrid, monolithic active and passive microwave electronic
circuits.
Ahmed Errkik was born in July 1960 in Morocco. He received the Ph.D. degree in physics from
the University of Technology Compie`gne (UTC), Compie`gne, France. He is currently an
associate Professor of physics in FST University Hassan 1st, Settat, Morocco. He is involved in
the design of hybrid, monolithic active and passive microwave electronic circuits.
9. ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 8, No. 6, December 2018 : 4496 - 4504
4504
Abdelali Tajmouati was born in, Morocco, in 1962. He received the Ph.D. degree in science
engineering from the University of Perpignan, France, in 1992. He is currently an associate
Professor of Electronics, thermal transfer and thermodynamic in Faculty of sciences and
techniques University Hassan 1st, Settat, Morocco. He is involved in the design of hybrid,
monolithic active and passive microwave electronic circuits.
Mohamed Latrach (IEEE member) received the Ph.D. degree in electronics from the University
of Limoges, Limoges, France, in 1990. He is currently Professor of microwave engineering with
the Ecole Supérieure d’Electronique de l’Ouest (ESEO), Angers, France, where he is head of the
Radio-Frequency & Microwave research group. His research interests include: design of hybrid
& monolithic active and passive microwave circuits, metamaterials, LH materials, antennas,
rectennas and their applications in wireless communications, and wireless power transmission
(WPT).