There is a mainly two types of waveguide which are mainly used in microwave transmission. A Rectangular waveguide and a circular waveguide. Microwave Propagation is being through these waveguides via different modes at different frequencies. But in practical implementation many problems arise like an ascetic excitation method, efficiency of particular mode, complex calculation etc., and an alternation is used. It is called a waveguide converter. In this paper different types of methods are analyzed and describe an output of these methods.
Waveguides are hollow conductive tubes that propagate electromagnetic waves within their interior. They serve as boundaries that confine EM energy through reflection off their walls. Common waveguide types include rectangular, circular, and helical waveguides. Key characteristics of waveguides include their cutoff frequency minimum operating frequency and modes of propagation within the guide.
The document provides an overview of microwave engineering and rectangular waveguides. It defines microwave frequencies as ranging from 1 GHz to 300 GHz. Rectangular waveguides transmit electromagnetic waves through successive reflections from inner walls. Modes in waveguides include transverse electric (TE) and transverse magnetic (TM) modes. The document analyzes the TM and TE modes in rectangular waveguides through solving Maxwell's equations with boundary conditions. Cut-off frequencies above which modes can propagate are determined. Examples demonstrate calculating waveguide parameters and resonant frequencies of cavity resonators.
1) Rectangular waveguides are commonly used to transmit microwave signals and their dimensions are based on the transmission frequency. Common waveguide shapes include rectangular, circular, and ridged.
2) Multiple electromagnetic modes can propagate within a waveguide depending on the frequency relative to the cutoff frequency for each mode. The dominant mode for rectangular waveguides is the TE10 mode.
3) Double ridge waveguides increase bandwidth at the cost of higher attenuation by lowering the cutoff frequency of the TE10 mode relative to an unloaded rectangular waveguide.
This document discusses different types of waveguides, including rectangular waveguides, circular waveguides, coaxial lines, optical waveguides, and parallel-plate waveguides. It describes the different modes of wave propagation including TEM, TE, TM, and HE modes. Cutoff frequencies and wavelengths are defined for rectangular and parallel-plate waveguides. Dominant TE10 mode is described for rectangular waveguides.
The document discusses the transverse electromagnetic (TEM) mode, which can exist in transmission lines but not hollow waveguides. The TEM mode is characterized by the electric and magnetic fields being completely transverse to the direction of wave propagation. Analysis of the TEM mode illustrates the relationship between circuit theory and field theory. The properties of TEM modes in a lossless medium include having a cutoff frequency of zero, requiring a two-conductor transmission line system, and having a wave impedance equal to the impedance in an unbounded dielectric medium with a phase velocity equal to the speed of light in that medium.
The cutoff frequency for the TE10 mode is given by fc = c/(2m) = 1.5×109 Hz.
The frequencies for TE01 and TE11 modes are higher than that of TE10 mode.
Since the operating frequency f = 109 rad/s = 1.5×109 Hz is greater than the cutoff frequency of TE10 mode, the TE10 mode will propagate. The other modes that can propagate are TE01 and TE11.
The correct option is C.
Waveguides are hollow conductive tubes that propagate electromagnetic waves within their interior. They serve as boundaries that confine EM energy through reflection off their walls. Common waveguide types include rectangular, circular, and helical waveguides. Key characteristics of waveguides include their cutoff frequency minimum operating frequency and modes of propagation within the guide.
The document provides an overview of microwave engineering and rectangular waveguides. It defines microwave frequencies as ranging from 1 GHz to 300 GHz. Rectangular waveguides transmit electromagnetic waves through successive reflections from inner walls. Modes in waveguides include transverse electric (TE) and transverse magnetic (TM) modes. The document analyzes the TM and TE modes in rectangular waveguides through solving Maxwell's equations with boundary conditions. Cut-off frequencies above which modes can propagate are determined. Examples demonstrate calculating waveguide parameters and resonant frequencies of cavity resonators.
1) Rectangular waveguides are commonly used to transmit microwave signals and their dimensions are based on the transmission frequency. Common waveguide shapes include rectangular, circular, and ridged.
2) Multiple electromagnetic modes can propagate within a waveguide depending on the frequency relative to the cutoff frequency for each mode. The dominant mode for rectangular waveguides is the TE10 mode.
3) Double ridge waveguides increase bandwidth at the cost of higher attenuation by lowering the cutoff frequency of the TE10 mode relative to an unloaded rectangular waveguide.
This document discusses different types of waveguides, including rectangular waveguides, circular waveguides, coaxial lines, optical waveguides, and parallel-plate waveguides. It describes the different modes of wave propagation including TEM, TE, TM, and HE modes. Cutoff frequencies and wavelengths are defined for rectangular and parallel-plate waveguides. Dominant TE10 mode is described for rectangular waveguides.
The document discusses the transverse electromagnetic (TEM) mode, which can exist in transmission lines but not hollow waveguides. The TEM mode is characterized by the electric and magnetic fields being completely transverse to the direction of wave propagation. Analysis of the TEM mode illustrates the relationship between circuit theory and field theory. The properties of TEM modes in a lossless medium include having a cutoff frequency of zero, requiring a two-conductor transmission line system, and having a wave impedance equal to the impedance in an unbounded dielectric medium with a phase velocity equal to the speed of light in that medium.
The cutoff frequency for the TE10 mode is given by fc = c/(2m) = 1.5×109 Hz.
The frequencies for TE01 and TE11 modes are higher than that of TE10 mode.
Since the operating frequency f = 109 rad/s = 1.5×109 Hz is greater than the cutoff frequency of TE10 mode, the TE10 mode will propagate. The other modes that can propagate are TE01 and TE11.
The correct option is C.
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Polarization insensitive switchable metamaterial absorber/reflector for X-ban...journalBEEI
A unit cell of squared shaped polarization-insensitive switchable metamaterial absorber/reflector is presented. The structure operates at 10.20 GHz under both absorber mode and reflector mode configurations. Copper wire bridging the gaps to form a circular shape structure were used as switches for operation mode selections. The structure was designed on an FR4 substrate, and the incidental wave angles were varied from 0 to 50 degrees. The structure demonstrated almost 100% absorption at resonance, 3.314 GHz percentage bandwidth at 80% as an absorber. On the other hand, as reflector, it demonstrated almost a 90% reflection and a usable bandwidth of 3.327 GHz.
1. Hollow waveguides present an alternative to transmission lines at microwave frequencies, as electromagnetic waves reflect from the walls of the waveguide as it travels its length.
2. A waveguide operates most efficiently within modal boundaries, where below a cutoff frequency a signal will not propagate, acting as a filter.
3. Multimode propagation results in different modes traveling at different velocities, causing pulse spreading and interference between closely following pulses.
This document discusses a Spatially Modulated Metamaterial Array for Transmit (SMMArT) concept for radar systems. SMMArT uses a slow-wave transmission line composed of a slotted Clarricoats-Waldron waveguide to enable spatial modulation of the transmit beam during each pulse without complex element-level waveform generation. Full-wave simulations examine the radiation patterns and performance of SMMArT under various excitation waveforms. A parametric study identifies design constraints for the waveguide slots to suppress undesired coupling between the forward and backward waveguide modes for single-mode operation.
1. Cut-off frequency is the frequency above which waves can propagate through a waveguide. Cut-off wavelength is the wavelength corresponding to the cut-off frequency.
2. TE modes have a transverse electric field and longitudinal magnetic field. TM modes have a transverse magnetic field and longitudinal electric field.
3. Circular waveguides have advantages over rectangular waveguides like being easier to manufacture and join, and allowing propagation of both vertically and horizontally polarized waves. They are used in applications requiring microwave transmission over long distances or high power handling like radar.
This document summarizes a study investigating the design and characteristics of directional coupler-based optical filters using coupled mode theory. The study examines a directional coupler consisting of two non-identical slab waveguides and analyzes power transfer between the waveguides. It is found that complete power exchange can occur when the waveguide modes are phase matched. The effects of structure parameters on filter response, crosstalk and bandwidth are also analyzed. A novel cascaded coupler structure is introduced to overcome limitations in conventional designs such as decreased coupling efficiency from non-identical waveguides.
This document provides an overview of transmission line theory and microwave transmission lines. It discusses the lumped element circuit model used to model transmission lines and the concept of wave propagation in transmission lines. It also covers different types of transmission lines including microstrip lines, waveguides, and coaxial cables. Key transmission line parameters are defined, such as characteristic impedance, cut-off frequency, and electromagnetic mode. Specific modes and characteristics are described for microstrip lines and rectangular waveguides.
Microwave transmission lines include coaxial cables, waveguides, and strip lines. Strip lines have configurations like microstrip lines, parallel strip lines, coplanar strip lines, and shielded strip lines. Microstrip lines use a conducting strip separated from a ground plane by a dielectric substrate. They have quasi-TEM mode transmission and characteristic impedances typically between 50-150 ohms. Power losses in microstrip lines include ohmic, dielectric, and radiation losses. The document derives equations for microstrip line characteristic impedance and propagation properties, and discusses sources of loss and quality factors.
Waveguides are hollow metal pipes that carry electromagnetic waves for microwave signals. The choice of waveguide structure depends on the operating frequency, power level, and acceptable transmission losses. Common waveguide structures include circular and rectangular waveguides. Waveguide couplers divert a fraction of the signal power from one transmission line to another. Waveguide impedance matching and devices like irises are used to reduce reflections at interfaces. Common components are bends, tees, and terminations.
IRJET- Design of a Slow Light Propagating Waveguide based on Electromagnetica...IRJET Journal
1. The document proposes a metal-insulator-metal (MIM) plasmonic waveguide system that can function as a subwavelength filter and exhibit slow light propagation based on electromagnetically induced transparency (EIT).
2. The MIM waveguide with stub structures is modeled and simulations show the system can function as a wavelength selective filter with transmission windows in the submicron range.
3. Transmission spectra are presented showing an EIT-like transparency window that can be tuned by changing the distance between stubs in the waveguide. The maximum transmittance wavelength increases linearly with stub depth.
Planar waveguides are an important type of waveguide that can be used in integrated circuits to connect microwave circuit elements. Examples include strip lines, microstrip lines, coplanar waveguides, and slotted lines. When designing a planar waveguide circuit, its characteristic impedance, dispersion, phase velocity, attenuation, and other parameters must be determined. Commercial software tools can help with designing waveguides to meet specifications for impedance and phase shift. Planar waveguides find applications in microwave integrated circuits, filters, phase shifters, and feeding energy from generators to antennas.
1. The document introduces microwave engineering concepts over 4 weeks, covering Maxwell's equations, plane wave solutions, propagation in lossy media, and S-parameters.
2. It describes applications of microwave engineering like wireless devices, 5G networks, satellite links, and direct broadcast. Maxwell's equations describe macroscopic electric and magnetic phenomena.
3. Plane waves have electric and magnetic fields perpendicular to the direction of propagation. The wave equation relates wavelength, frequency, and speed of waves. Plane waves in lossy media have complex propagation constants that cause amplitude changes over distance.
1) Researchers measured the lift, drag, and guidance forces on a permanent magnet passing over different arrays of figure-eight coils. The experimental results matched well with predictions from dynamic circuit theory.
2) In experiments, a magnet passed over single coils and arrays with 2, 4, or 8 coils while forces were measured. Lift forces pushed towards the coil center, while drag and guidance forces had impulse patterns that varied with coil number.
3) Dynamic circuit theory models the magnet and coils as circuits and calculates induced currents and magnetic forces. The calculated force waveforms matched the measured results well. Analysis of coil designs can optimize forces for maglev applications.
This paper investigates a novel dual-rotor permanent magnet synchronous motor (DRPMSM) through modeling and simulation. The model of the DRPMSM is constructed in MATLAB/Simulink. Vector control and space vector PWM control strategies are used to simulate the motor model. The simulation results show the model operates correctly under both control strategies. The responses of torque, speed and current are analyzed and compared under the different control strategies. Key characteristics of the DRPMSM such as the relationship between the speeds of the inner and outer rotors are also analyzed.
Rectangular waveguides are the most commonly used form and carry signals above a certain cutoff frequency. They propagate electromagnetic waves in different modes depending on whether the electric or magnetic vector is perpendicular to the propagation direction. For rectangular waveguides, the width determines the lower cutoff frequency and the TE10 mode is the lowest supported. Circular waveguides are less common but used when a rotating element is attached; they support all TEmn and TMmn modes with the dominant mode being TE11.
This document describes the design and modeling of a linear switched reluctance motor (LSRM) to drive an infusion pump. Key points:
- LSRMs are being used more in industries due to advances in power electronics. They have robust builds and don't require transmission systems like gears.
- The authors designed an LSRM-driven infusion pump with improved resolution and power utilization over previous models. They modeled the LSRM and developed control algorithms to precisely control syringe movement and drug dosage.
- The LSRM design process involved first translating specifications to an equivalent rotating switched reluctance motor design. The rotary motor was designed and dimensions converted back to the linear design. Design equations and a procedure are provided
This document analyzes the modeling of overhead transmission lines for lightning studies. It summarizes guidelines for modeling transmission line components like towers, grounding impedance, and insulator strings. It then models a 400kV transmission line in Albania using these guidelines. Simulation results show that towers with higher characteristic impedance and grounding resistance experience lower peak lightning currents. Accurately modeling transmission line components is important for evaluating lightning performance and maintenance.
This paper presents the review of design variables optimization and control strategies of a Linear Switched Reluctance Actuator (LSRA). The introduction of various type of linear electromagnetic actuators (LEA) are compared and the advantages of LSRA over other LEA are discussed together with the type of actuator configurations and topologies. The SRA provides an overall efficiency similar to induction actuator of the similar rating, subsequently the friction and windage losses are comparable but force density is better. LSRA has the advantage of low cost, simple construction and high reliability compare to the actuator with permanent magnet. However, LSRA also has some obvious defects which will influence the performance of the actuator such as ripples and acoustic noise which are caused by the highly nonlinear characteristics of the actuator. By researching the design variables of the actuator, the influences of those design variables are introduced and the detail comparisons are analyzed in this paper. In addition, this paper also reviews on the control strategies in order to overcome the weaknesses of LSRA.
Modelling Optical Waveguide Bends by the Method of LinesTELKOMNIKA JOURNAL
A rigorous analytical and semi analytical method of lines has been used to calculate the
transverse-electric field attenuation coefficient of guided mode as it travels in waveguide bends structure.
Both approaches then were compared to get a better understanding on how the attenuation behaves along
single curve waveguides with constant radius of curvature. The Helmholtz Equation in polar coordinate
was transformed into a curvalinier coordinate to simulate the waveguide bends using the method of line
analysis. The simple absorption boundary conditions are used into the method of lines to demonstrate
evanescent field of the guided mode nature as its travels in waveguide bends structures. The results show
that a reasonable agreement between both theoretical approaches.
COUPLER, POWER DIVIDER AND CIRCULATOR IN V-BAND SUBSTRATE INTEGRATED WAVEGUID...ijcsa
The document summarizes the design and simulation of substrate integrated waveguide (SIW) components in V-band, including a coupler, power divider, and circulator. Key findings are:
1) A SIW coupler, power divider, and circulator were designed using HFSS software and optimized to operate in the 50-75 GHz V-band.
2) Simulation results showed the coupler achieved reflection and isolation below -15 dB across 26.43% of the band. The power divider achieved reflection below -15 dB across 19.82% of the band.
3) The circulator achieved reflection below -15 dB across 6% of the band, insertion loss of around -0
This document describes an electromagnetic wave radiator for radiating approximately circularly polarized waves. It comprises a horn with a rectangular cross-section and means to feed two orthogonal plane polarized waves of the same wavelength into the throat of the horn. The dimensions of the horn are such that one wave is delayed by nλ/4 relative to the other wave at the mouth, producing approximately circular polarization. Various arrangements are provided for feeding the two orthogonal waves into the throat, including using dielectric strips, metal fins, or an elliptical cross-section to induce a phase delay between the waves.
This document discusses different types of electromagnetic waves that can propagate in waveguides, including transverse electric (TE), transverse magnetic (TM), and transverse electromagnetic (TEM) modes. It focuses on analyzing TE and TM modes in rectangular waveguides. Only certain discrete modes are allowed to propagate depending on the waveguide dimensions and frequency. Both TE and TM modes have cutoff frequencies below which propagation does not occur. In an X-band rectangular waveguide, only the TE10 mode can propagate from 6.56 to 13.12 GHz, which is called the dominant mode.
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
Polarization insensitive switchable metamaterial absorber/reflector for X-ban...journalBEEI
A unit cell of squared shaped polarization-insensitive switchable metamaterial absorber/reflector is presented. The structure operates at 10.20 GHz under both absorber mode and reflector mode configurations. Copper wire bridging the gaps to form a circular shape structure were used as switches for operation mode selections. The structure was designed on an FR4 substrate, and the incidental wave angles were varied from 0 to 50 degrees. The structure demonstrated almost 100% absorption at resonance, 3.314 GHz percentage bandwidth at 80% as an absorber. On the other hand, as reflector, it demonstrated almost a 90% reflection and a usable bandwidth of 3.327 GHz.
1. Hollow waveguides present an alternative to transmission lines at microwave frequencies, as electromagnetic waves reflect from the walls of the waveguide as it travels its length.
2. A waveguide operates most efficiently within modal boundaries, where below a cutoff frequency a signal will not propagate, acting as a filter.
3. Multimode propagation results in different modes traveling at different velocities, causing pulse spreading and interference between closely following pulses.
This document discusses a Spatially Modulated Metamaterial Array for Transmit (SMMArT) concept for radar systems. SMMArT uses a slow-wave transmission line composed of a slotted Clarricoats-Waldron waveguide to enable spatial modulation of the transmit beam during each pulse without complex element-level waveform generation. Full-wave simulations examine the radiation patterns and performance of SMMArT under various excitation waveforms. A parametric study identifies design constraints for the waveguide slots to suppress undesired coupling between the forward and backward waveguide modes for single-mode operation.
1. Cut-off frequency is the frequency above which waves can propagate through a waveguide. Cut-off wavelength is the wavelength corresponding to the cut-off frequency.
2. TE modes have a transverse electric field and longitudinal magnetic field. TM modes have a transverse magnetic field and longitudinal electric field.
3. Circular waveguides have advantages over rectangular waveguides like being easier to manufacture and join, and allowing propagation of both vertically and horizontally polarized waves. They are used in applications requiring microwave transmission over long distances or high power handling like radar.
This document summarizes a study investigating the design and characteristics of directional coupler-based optical filters using coupled mode theory. The study examines a directional coupler consisting of two non-identical slab waveguides and analyzes power transfer between the waveguides. It is found that complete power exchange can occur when the waveguide modes are phase matched. The effects of structure parameters on filter response, crosstalk and bandwidth are also analyzed. A novel cascaded coupler structure is introduced to overcome limitations in conventional designs such as decreased coupling efficiency from non-identical waveguides.
This document provides an overview of transmission line theory and microwave transmission lines. It discusses the lumped element circuit model used to model transmission lines and the concept of wave propagation in transmission lines. It also covers different types of transmission lines including microstrip lines, waveguides, and coaxial cables. Key transmission line parameters are defined, such as characteristic impedance, cut-off frequency, and electromagnetic mode. Specific modes and characteristics are described for microstrip lines and rectangular waveguides.
Microwave transmission lines include coaxial cables, waveguides, and strip lines. Strip lines have configurations like microstrip lines, parallel strip lines, coplanar strip lines, and shielded strip lines. Microstrip lines use a conducting strip separated from a ground plane by a dielectric substrate. They have quasi-TEM mode transmission and characteristic impedances typically between 50-150 ohms. Power losses in microstrip lines include ohmic, dielectric, and radiation losses. The document derives equations for microstrip line characteristic impedance and propagation properties, and discusses sources of loss and quality factors.
Waveguides are hollow metal pipes that carry electromagnetic waves for microwave signals. The choice of waveguide structure depends on the operating frequency, power level, and acceptable transmission losses. Common waveguide structures include circular and rectangular waveguides. Waveguide couplers divert a fraction of the signal power from one transmission line to another. Waveguide impedance matching and devices like irises are used to reduce reflections at interfaces. Common components are bends, tees, and terminations.
IRJET- Design of a Slow Light Propagating Waveguide based on Electromagnetica...IRJET Journal
1. The document proposes a metal-insulator-metal (MIM) plasmonic waveguide system that can function as a subwavelength filter and exhibit slow light propagation based on electromagnetically induced transparency (EIT).
2. The MIM waveguide with stub structures is modeled and simulations show the system can function as a wavelength selective filter with transmission windows in the submicron range.
3. Transmission spectra are presented showing an EIT-like transparency window that can be tuned by changing the distance between stubs in the waveguide. The maximum transmittance wavelength increases linearly with stub depth.
Planar waveguides are an important type of waveguide that can be used in integrated circuits to connect microwave circuit elements. Examples include strip lines, microstrip lines, coplanar waveguides, and slotted lines. When designing a planar waveguide circuit, its characteristic impedance, dispersion, phase velocity, attenuation, and other parameters must be determined. Commercial software tools can help with designing waveguides to meet specifications for impedance and phase shift. Planar waveguides find applications in microwave integrated circuits, filters, phase shifters, and feeding energy from generators to antennas.
1. The document introduces microwave engineering concepts over 4 weeks, covering Maxwell's equations, plane wave solutions, propagation in lossy media, and S-parameters.
2. It describes applications of microwave engineering like wireless devices, 5G networks, satellite links, and direct broadcast. Maxwell's equations describe macroscopic electric and magnetic phenomena.
3. Plane waves have electric and magnetic fields perpendicular to the direction of propagation. The wave equation relates wavelength, frequency, and speed of waves. Plane waves in lossy media have complex propagation constants that cause amplitude changes over distance.
1) Researchers measured the lift, drag, and guidance forces on a permanent magnet passing over different arrays of figure-eight coils. The experimental results matched well with predictions from dynamic circuit theory.
2) In experiments, a magnet passed over single coils and arrays with 2, 4, or 8 coils while forces were measured. Lift forces pushed towards the coil center, while drag and guidance forces had impulse patterns that varied with coil number.
3) Dynamic circuit theory models the magnet and coils as circuits and calculates induced currents and magnetic forces. The calculated force waveforms matched the measured results well. Analysis of coil designs can optimize forces for maglev applications.
This paper investigates a novel dual-rotor permanent magnet synchronous motor (DRPMSM) through modeling and simulation. The model of the DRPMSM is constructed in MATLAB/Simulink. Vector control and space vector PWM control strategies are used to simulate the motor model. The simulation results show the model operates correctly under both control strategies. The responses of torque, speed and current are analyzed and compared under the different control strategies. Key characteristics of the DRPMSM such as the relationship between the speeds of the inner and outer rotors are also analyzed.
Rectangular waveguides are the most commonly used form and carry signals above a certain cutoff frequency. They propagate electromagnetic waves in different modes depending on whether the electric or magnetic vector is perpendicular to the propagation direction. For rectangular waveguides, the width determines the lower cutoff frequency and the TE10 mode is the lowest supported. Circular waveguides are less common but used when a rotating element is attached; they support all TEmn and TMmn modes with the dominant mode being TE11.
This document describes the design and modeling of a linear switched reluctance motor (LSRM) to drive an infusion pump. Key points:
- LSRMs are being used more in industries due to advances in power electronics. They have robust builds and don't require transmission systems like gears.
- The authors designed an LSRM-driven infusion pump with improved resolution and power utilization over previous models. They modeled the LSRM and developed control algorithms to precisely control syringe movement and drug dosage.
- The LSRM design process involved first translating specifications to an equivalent rotating switched reluctance motor design. The rotary motor was designed and dimensions converted back to the linear design. Design equations and a procedure are provided
This document analyzes the modeling of overhead transmission lines for lightning studies. It summarizes guidelines for modeling transmission line components like towers, grounding impedance, and insulator strings. It then models a 400kV transmission line in Albania using these guidelines. Simulation results show that towers with higher characteristic impedance and grounding resistance experience lower peak lightning currents. Accurately modeling transmission line components is important for evaluating lightning performance and maintenance.
This paper presents the review of design variables optimization and control strategies of a Linear Switched Reluctance Actuator (LSRA). The introduction of various type of linear electromagnetic actuators (LEA) are compared and the advantages of LSRA over other LEA are discussed together with the type of actuator configurations and topologies. The SRA provides an overall efficiency similar to induction actuator of the similar rating, subsequently the friction and windage losses are comparable but force density is better. LSRA has the advantage of low cost, simple construction and high reliability compare to the actuator with permanent magnet. However, LSRA also has some obvious defects which will influence the performance of the actuator such as ripples and acoustic noise which are caused by the highly nonlinear characteristics of the actuator. By researching the design variables of the actuator, the influences of those design variables are introduced and the detail comparisons are analyzed in this paper. In addition, this paper also reviews on the control strategies in order to overcome the weaknesses of LSRA.
Modelling Optical Waveguide Bends by the Method of LinesTELKOMNIKA JOURNAL
A rigorous analytical and semi analytical method of lines has been used to calculate the
transverse-electric field attenuation coefficient of guided mode as it travels in waveguide bends structure.
Both approaches then were compared to get a better understanding on how the attenuation behaves along
single curve waveguides with constant radius of curvature. The Helmholtz Equation in polar coordinate
was transformed into a curvalinier coordinate to simulate the waveguide bends using the method of line
analysis. The simple absorption boundary conditions are used into the method of lines to demonstrate
evanescent field of the guided mode nature as its travels in waveguide bends structures. The results show
that a reasonable agreement between both theoretical approaches.
COUPLER, POWER DIVIDER AND CIRCULATOR IN V-BAND SUBSTRATE INTEGRATED WAVEGUID...ijcsa
The document summarizes the design and simulation of substrate integrated waveguide (SIW) components in V-band, including a coupler, power divider, and circulator. Key findings are:
1) A SIW coupler, power divider, and circulator were designed using HFSS software and optimized to operate in the 50-75 GHz V-band.
2) Simulation results showed the coupler achieved reflection and isolation below -15 dB across 26.43% of the band. The power divider achieved reflection below -15 dB across 19.82% of the band.
3) The circulator achieved reflection below -15 dB across 6% of the band, insertion loss of around -0
This document describes an electromagnetic wave radiator for radiating approximately circularly polarized waves. It comprises a horn with a rectangular cross-section and means to feed two orthogonal plane polarized waves of the same wavelength into the throat of the horn. The dimensions of the horn are such that one wave is delayed by nλ/4 relative to the other wave at the mouth, producing approximately circular polarization. Various arrangements are provided for feeding the two orthogonal waves into the throat, including using dielectric strips, metal fins, or an elliptical cross-section to induce a phase delay between the waves.
This document discusses different types of electromagnetic waves that can propagate in waveguides, including transverse electric (TE), transverse magnetic (TM), and transverse electromagnetic (TEM) modes. It focuses on analyzing TE and TM modes in rectangular waveguides. Only certain discrete modes are allowed to propagate depending on the waveguide dimensions and frequency. Both TE and TM modes have cutoff frequencies below which propagation does not occur. In an X-band rectangular waveguide, only the TE10 mode can propagate from 6.56 to 13.12 GHz, which is called the dominant mode.
This document discusses models for predicting path loss of sky wave and ground wave propagation in the HF frequency range. It recommends using the ICEPAC program from the IONCAP family to predict sky wave propagation path loss, as it is the most advanced model and has been effectively used for frequency planning. For ground wave propagation prediction, it discusses different models available and the factors that influence path loss, such as ground conductivity.
The document outlines a lecture on microwave devices that discusses general solutions for transverse electromagnetic (TEM), transverse electric (TE), and transverse magnetic (TM) waves. It then covers rectangular and circular waveguides, discussing their boundary conditions and dominant modes like the TE10 mode in rectangular waveguides and TE and TM modes in circular waveguides.
The document discusses electromagnetic waves and radio frequency (RF) fundamentals. It explains that electromagnetic waves consist of oscillating electric and magnetic fields perpendicular to each other and the direction of propagation. It also discusses how antennas generate electromagnetic waves through alternating current, and how the shape of the antenna determines the direction the waves propagate. Finally, it provides an overview of RF characteristics such as wavelength, frequency, amplitude, and phase.
The document summarizes different types of transmission cables including coaxial cable, twisted pair cable, and fiber optic cable. Coaxial cable uses a central conductor surrounded by insulation and shielding, and was commonly used in early Ethernet networks. Twisted pair cable consists of two copper wires twisted together to reduce interference, and comes in unshielded and shielded varieties. Fiber optic cable uses glass cores to transmit light signals and is more expensive but can transmit over greater distances and speeds with less signal loss than other cables.
This document discusses microwave devices, specifically directional couplers and isolators. It begins by defining microwaves and their applications such as telecommunications and radar. It then describes how directional couplers are passive devices that divide power through four ports and discusses their key figures of merit like coupling factor, isolation, and directivity. Isolators are also covered as two-port non-reciprocal devices that allow high power transmission in one direction while providing high attenuation in the opposite direction using Faraday rotation in a ferrite rod.
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.
basic electronics, Transmission lines, wave guides And Antenna fundamentalAdarsh Patel
This document discusses the units used to measure properties of transmission lines, including loop resistance measured in ohms per metre, loop inductance in henries per metre, insulator capacitance in farads per metre, and insulator conductance in siemens per metre. It also notes that the angle of incidence equals the angle of reflection.
1) The document discusses transmission lines and their characteristics. It describes different types of transmission lines including coaxial lines, two-wire lines, and microstrip lines.
2) It presents the telegrapher's equations which model voltage and current on a transmission line as a function of position and time. These equations include parameters like inductance and capacitance per unit length.
3) Waves can propagate down transmission lines, maintaining their shape as they travel at a characteristic velocity. The wavelength depends on the wave velocity and frequency. Phasors are used to represent sinusoidal waves independent of time.
This document provides an overview of a nonresident training course on electronics technician volume 7, which covers antennas and wave propagation. Specifically, it will discuss wave propagation with regards to how the earth's atmosphere affects it and how to optimize equipment performance. It will also cover identifying communications and radar antennas by physical characteristics, installation locations, radiation patterns and power/frequency capabilities. The course is self-paced and organized into chapters covering the topics. It is designed to help electronics technicians study for advancement and improve their knowledge of relevant military topics.
This document provides an overview of basic electronics topics including transmission lines, waveguides, and antenna fundamentals. It discusses the characteristics and applications of transmission lines, advantages of using them to reduce electromagnetic interference, and examples of different types of transmission lines. Waveguides are introduced as an alternative to transmission lines at higher frequencies. Key concepts around waveguides such as applications and the expression for cutoff wavelength are summarized. Finally, the document outlines fundamental concepts relating to antennas such as radiation patterns, efficiency, and gain.
A directional coupler is a passive device that couples part of the transmission power from one transmission line to another. It has four ports: input, transmitted, coupled, and isolated. Key parameters are coupling factor, loss, isolation, and directivity. Directional couplers are commonly used to monitor power and frequency without interrupting the main signal, for frequency and power measurements, and combining signals to a receiver when isolation is high.
Transmission Media, Guided and unguided transmission mediaadnanqayum
Transmission Media and its types, Guided and unguided transmission media with examples (guided = (i) Twisted pair cable (ii) Coaxial cable (iii) Fiber optical cable, unguided = (i) Radio wave (ii) Microwave (iii) Infra-red wave)
This document discusses different types of transmission media used for data communication. It describes guided media like twisted pair wires, coaxial cables, and optical fibers. It also covers wireless or unguided media such as terrestrial microwave, satellite microwave, broadcast radio, and infrared. For each medium, it provides details on characteristics, advantages, disadvantages, and applications. The key factors that affect the quality of a transmission medium are its bandwidth, interference levels, and transmission impairments. Optical fiber has the highest bandwidth capacity but was initially more expensive over short distances.
This document discusses different types of transmission media used for data communication. It describes guided media such as twisted pair cables, coaxial cables, and fiber optic cables. It also covers unguided or wireless media such as radio waves, microwaves, and infrared. For each medium, it provides details on their characteristics, applications, advantages and disadvantages. The document aims to classify and explain the basic concepts of different transmission media and their use in data communication networks.
Microwave antennas can take several forms. Horn antennas are popular and can achieve gains up to 25 dB, with directional patterns. Parabolic antennas, like satellite dishes, typically have very high gain between 30-40 dB and low cross polarization. Slot antennas are often used instead of line antennas for greater pattern control and are found in radar and cell antennas. Dipole antennas are half wave resonant conductors that radiate omnidirectionally at right angles to their axis. Their gain is approximately 2 dBi. Dielectric antennas use a traveling surface wave along a dielectric rod to radiate maximally along the rod axis.
The document summarizes key aspects of transmission line design and components. It discusses the methodology for designing transmission lines, including gathering design data, selecting reliability levels, and calculating loads. It also covers the selection and design of various transmission line components such as conductors, insulators, towers, and grounding systems. Design considerations include voltage levels, safety clearances, mechanical requirements, and optimization of costs.
1. The document discusses various types of waveguides used to transmit electromagnetic waves, including rectangular waveguides, circular waveguides, coaxial lines, optical waveguides, and parallel-plate waveguides.
2. It describes the properties of parallel-plate waveguides, including their TE and TM modes. The TE modes have the electric field parallel to the plates, while the TM modes have the magnetic field parallel to the plates.
3. Cutoff frequencies are discussed, below which modes do not propagate. The cutoff wavelength is the wavelength at which the phase constant is zero.
Network effects. It’s one of the most important concepts for business in general and especially for tech businesses, as it’s the key dynamic behind many successful software-based companies. Understanding network effects not only helps build better products, but it helps build moats and protect software companies against competitors’ eating away at their margins.
Yet what IS a network effect? How do we untangle the nuances of 'network effects' with 'marketplaces' and 'platforms'? What’s the difference between network effects, virality, supply-side economies of scale? And how do we know a company has network effects?
Most importantly, what questions can entrepreneurs and product managers ask to counter the wishful thinking and sometimes faulty assumption behind the belief that “if we build it, they will come” … and instead go about more deterministically creating network effects in their business? Because it's not a winner-take-all market by accident.
A waveguide is a hollow metallic tube that transmits electromagnetic waves through successive reflections off the inner walls. There are two common modes of propagation in a waveguide: transverse magnetic (TM) and transverse electric (TE). Waveguides come in different shapes including rectangular, circular, elliptical, single ridged, and double ridged. Microwaves propagate through waveguides in distinct field patterns called modes of propagation such as TEM, TE, TM, and HE. Important waveguide parameters include cut-off wavelength, group velocity, phase velocity, and wave impedance.
A waveguide is a structure that guides electromagnetic waves along its length. Rectangular waveguides consist of a hollow metal tube with a rectangular cross-section. Circular waveguides use a cylindrical cross-section. Waveguides can support transverse electric (TE) and transverse magnetic (TM) modes of propagation above a cutoff frequency that depends on the waveguide dimensions. Common applications include microwave communications, radar installations, and feeding antenna horns and dishes.
Teori Medan Elektromagnet (5 - 7) pandu_gelombangjayamartha
The document discusses different modes of propagation for electromagnetic waves including TE, TM, and TEM modes. It explains that TE modes have electric fields perpendicular to the direction of propagation, TM modes have magnetic fields perpendicular to propagation, and TEM modes have both electric and magnetic fields perpendicular to propagation. It also discusses the cutoff frequency and wavelength for different waveguide modes and provides an example of calculating these values for a rectangular waveguide.
This document discusses ferrite phase shifters. It begins by defining ferrites as magnetic materials used in microwave applications due to their electric and magnetic anisotropy. It then discusses three main types of ferrite phase shifters: latching ferrite phase shifters, dual mode ferrite phase shifters, and rotary field ferrite phase shifters. Latching ferrite phase shifters include twin toroid designs that induce a phase shift by modifying the transmission line propagation constant. Dual mode ferrite phase shifters convert signals to circular polarization to interact with a ferrite rod under a bias field, producing a phase shift. Rotary field ferrite phase shifters rotate a ferrite half-wave plate to produce a phase
Waveguides are structures that guide electromagnetic waves along a path with minimal loss of energy. They are made of conductive materials and have a specific shape that allows them to guide electromagnetic waves. Waveguides can support multiple modes of propagation, each with a different wavelength and frequency, and their ability to propagate modes depends on dimensions and shape. Waveguides are used in applications like telecommunications, radar, and microwave ovens to transmit electromagnetic waves.
This document provides information about circular waveguides. It begins by defining a circular waveguide as a tubular circular conductor that supports TE or TM wave propagation modes. Cutoff wavelengths depend on the internal radius of the waveguide. Common modes for circular waveguides are labeled similarly to rectangular waveguides. The document also provides examples of calculating cutoff wavelengths and wavelengths in a guide for a given signal frequency and waveguide dimensions. It concludes by discussing microstrip and stripline transmission lines used at higher microwave frequencies when waveguides become impractical.
This document analyzes a transistor clamped H-bridge split phase PWM inverter. It presents the circuit diagram of the proposed inverter which uses coupled inductors to prevent short circuits and reduce reverse recovery losses. A double reference single carrier modulation technique is used to generate PWM signals from two reference signals and a triangular carrier, producing a five-level output voltage. Simulation results in MATLAB Simulink show the five-level output voltage waveform and total harmonic distortion of 8.43%, demonstrating reduced harmonics compared to conventional inverters. The proposed inverter topology and modulation control method aim to improve efficiency, reliability and output waveform quality.
This paper presents a phase shifted series resonant converter with step up high frequency transformer to achieve the functions of high output voltage, high power density and wide range of Zero Voltage Switching (ZVS). In this approach, the output voltage is controlled by varying the switching frequency. The controller has been designed to achieve a good stability under different load conditions. The converter will react to the load variation by varying its switching frequency to satisfy the output voltage requirements. Therefore in order to maintain constant output voltage, for light load (50% of the load), the switching frequency will be decreased to meet the desired output, while for the full load (100%) conditions, the switching frequency will be increased. Since the controlled switching frequency is limited by the range between the higher and lower resonant frequencies , the switches can be turned on under ZVS. In this study, a laboratory experiment has been conducted to verify the effectiveness of the system performance.
This paper presents a study on a new full bridge series resonant converter (SRC) with wide zero voltage switching (ZVS) range, and higher output voltage. The high frequency transformer is connected in series with the LC series resonant tank. The tank inductance is therefore increased; all switches having the ability to turn on at ZVS, with lower switching frequency than the LC tank resonant frequency. Moreover, the step-up high frequency (HF) transformer design steps are introduced in order to increase the output voltage to overcome the gain limitation of the conventional SRC. Compared to the conventional SRC, the proposed converter has higher energy conversion, able to increase the ZVS range by 36%, and provide much higher output power. Finally, the a laboratory prototypes of the both converters with the same resonant tank parameters and input voltage are examined based on 1 and 2.2 kW power respectively, for veryfing the reliability of the performance and the operation principles of both converters.
This document discusses waveguide to suspended stripline transition techniques at 94 GHz. It describes two types of probe transitions that were designed and simulated. Type I uses a top excitation and rectangular probe on a 5 mil RT Duroid substrate. Type II uses side excitation and a rectangular probe. The best results were achieved with Type II, which has been used to realize bandpass filters, couplers, and crossbar mixers operating at 94 GHz. Both transitions were fabricated and tested, with the probe shape, depth and shorting plane optimized using electromagnetic simulation software.
Design & Implementation of Zero Voltage Switching Buck ConverterIJERA Editor
Zero voltage switching (ZVS) buck converter is more preferable over hard switched buck converter for low power, high frequency DC-DC conversion applications. In Zero voltage switching converter, turn on & turn off of a switch occurs at zero voltage that results in lower switching losses. In this converter soft switching is achieved by using resonant components. The optimal values of resonant components are determined by using electric functions derived from circuit configuration. This type of soft switched resonant converter offers very low electromagnetic interference (EMI).This study presents the circuit configuration with least components to realize highly efficient zero voltage switching resonant converter. It’s feasibility is confirmed with the developed proto type model and experimental results are verified.
The document discusses waveguides, which are hollow metallic tubes that transmit electromagnetic waves through successive reflections off the inner walls. There are two main types of waveguides: rectangular and circular. Rectangular waveguides support TE and TM modes of propagation, with the dominant TE10 mode determining the cutoff frequency below which waves do not propagate. Circular waveguides have advantages like greater power handling capacity but are larger in size. Common applications of waveguides include radar systems and long-distance high-frequency signal transmission.
This summary provides the key points about a study on frequency-tracking wireless power transfer systems using resonant coupling:
1) Detuning is a barrier to resonant coupling wireless power transfer, as changes in coil inductances can reduce transmission efficiency.
2) A new frequency tracking control method is proposed where the transmitting power source frequency tracks the natural frequency of the launching resonant circuit automatically to avoid detuning and improve efficiency.
3) An experimental 1 MHz wireless power transfer prototype was built using this frequency tracking method, and results showed it performed well in maintaining high transmission efficiency despite changes in coil inductances.
Transmission spectra of single ring coupled-waveguide resonator configuration...TELKOMNIKA JOURNAL
Development of optical waveguide resonators have greatly expanded and continues to grow since they have kinds potential applications such as wavelength filtering, switching, coupling and multiplexing. One of resonators, coupled waveguides, ring resonators are designed and operated using various coupling configurations. Ring resonators can be particularly used as wavelength filter if the wavelength can fit a whole multiple time in the circumference of the ring. This article proposes to investigate the transmission spectra from the power source and amplify it in linearized ring resonator configurations and varies the input amplitude on five different wavelengths. With finite difference time domain method, the geometry and power source are simulated to obtain the better result and configuration. The results show the intensity phenomena of filtering in optical circuit.
This document is the seminar paper on transformers submitted by Pankaj Chaudhary, an electrical engineering student at Sanjay Gandhi Institute of Engineering & Technology, for his Bachelor of Technology degree. The paper discusses the basic construction, principles, types, cooling systems and applications of transformers. It explains how transformers work by transferring electrical energy from one circuit to another through magnetic induction without changing frequency, and how this principle allows efficient long-distance power transmission.
Two-section branch-line hybrid couplers based broadband transmit/receive switchIJECEIAES
This article introduces a broadband microstripline-based transmit/receive switch for 7-Tesla magnetic resonance imaging. The designed switch aims to handle a signal of multiple frequencies to/from a multi-tuned radio-frequency coil that resonates at frequencies corresponding to the speed of precession of a wide range of atomic X-nuclei, at the same time and without tuning. These include 1H, 23Na, 13C, 31P, 19F, and 7Li used in magnetic resonance spectroscopy as a measure to the existence of many diseases. The fundamental and third harmonic center frequencies of the switch are adjusted to resonate at two broadbands covering a wide range of atomic X-nuclei. Two section branch-line hybrid couplers with phase inverters are designed to build the broadband switch. The designed switch used the minimum trace widths of transmission lines that reveal a compact size without increasing the heat and then the loss beyond specific values. The couplers and the switch S-parameters exhibited good return loss (<-10 dB), high isolation (<-40 dB), less insertion loss (<1 dB) and two clear wide bands covering many atomic X-nuclei used in diagnosis, at the same time and without the need for any tuning circuit during operation.
Analysis of Multilevel Inverter using Bipolar and Unipolar Switching Schemes ...ijsrd.com
Cascaded H-bridge Multilevel Inverter (MLI) is most efficient topology for medium and high voltage DC-AC conversion, having less output harmonics and less commutation losses. Disadvantages are their complexity, more number of power devices, passive components and a complex control circuitry. Here a Cascaded Hybrid Multilevel Inverter is used to produce a three phase 9-level output voltages. Now a day inverter is also know as a DC-AC converter, is one of the most popular part of electrical device. This proposed inverter widely used in industries application such as speed control of induction motor. This thesis focus on three phase 9-level bipolar and unipolar switching inverter with characteristics like output voltage boosting ability and also we discus about the bipolar and unipolar switching scheme along with capacitor voltage control. The modified topology uses Cascaded H-bridge (CHB) with bidirectional and unidirectional switches producing boost up output voltage. Here a hybrid Pulse Width Modulation (PWM) technique is applied to control the power devices. This modulation technique uses a sine wave and a repeating wave, these waves are combined and a complete reference wave is generated. There is comparative study between CHB and modified topology between number of power devices used and Total Harmonic Distortions (THD). THD of modified topology is reduced and analyzed by FFT window. The results are observed by MATLAB/SIMULINK software.
This document describes the design and analysis of a 5-bit RF MEMS switched line phase shifter. RF MEMS switches have advantages over other technologies like low loss and high isolation. The phase shifter consists of five different phase shift sections (11.25, 22.5, 45, 90, 180 degrees) using MEMS capacitive series switches on a coplanar waveguide. A novel cantilever beam switch is designed with low actuation voltage and switching time. Simulation results showed the switch achieved less than 0.1dB insertion loss and over 19dB isolation at 20GHz with a 5V actuation voltage and 0.1us switching time. The 5-bit phase shifter demonstrated the ability to achieve
Optical Current Transformer is an alternative to the existing conventional current transformers, providing an advanced measurement solution for both metering and protection applications, based on a cutting-edge patented optical sensing technology.
Similar to Analysis on a Waveguide Mode Converter (20)
Due to availability of internet and evolution of embedded devices, Internet of things can be useful to contribute in energy domain. The Internet of Things (IoT) will deliver a smarter grid to enable more information and connectivity throughout the infrastructure and to homes. Through the IoT, consumers, manufacturers and utility providers will come across new ways to manage devices and ultimately conserve resources and save money by using smart meters, home gateways, smart plugs and connected appliances. The future smart home, various devices will be able to measure and share their energy consumption, and actively participate in house-wide or building wide energy management systems. This paper discusses the different approaches being taken worldwide to connect the smart grid. Full system solutions can be developed by combining hardware and software to address some of the challenges in building a smarter and more connected smart grid.
A Survey Report on : Security & Challenges in Internet of Thingsijsrd.com
In the era of computing technology, Internet of Things (IoT) devices are now popular in each and every domains like e-governance, e-Health, e-Home, e-Commerce, and e-Trafficking etc. Iot is spreading from small to large applications in all fields like Smart Cities, Smart Grids, Smart Transportation. As on one side IoT provide facilities and services for the society. On the other hand, IoT security is also a crucial issues.IoT security is an area which totally concerned for giving security to connected devices and networks in the IoT .As, IoT is vast area with usability, performance, security, and reliability as a major challenges in it. The growth of the IoT is exponentially increases as driven by market pressures, which proportionally increases the security threats involved in IoT The relationship between the security and billions of devices connecting to the Internet cannot be described with existing mathematical methods. In this paper, we explore the opportunities possible in the IoT with security threats and challenges associated with it.
In today’s emerging world of Internet, each and every thing is supposed to be in connected mode with the help of billions of smart devices. By connecting all the devises used in our day to day life, make our life trouble less and easy. We are incorporated in a world where we are used to have smart phones, smart cars, smart gadgets, smart homes and smart cities. Different institutes and researchers are working for creating a smart world for us but real question which we need to emphasis on is how to make dumb devises talk with uncommon hardware and communication technology. For the same what kind of mechanism to use with various protocols and less human interaction. The purpose is to provide the key area for application of IoT and a platform on which various devices having different mechanism and protocols can communicate with an integrated architecture.
Study on Issues in Managing and Protecting Data of IOTijsrd.com
This paper discusses variety of issues for preserving and managing data produced by IoT. Every second large amount of data are added or updated in the IoT databases across the heterogeneous environment. While managing the data each phase of data processing for IoT data is exigent like storing data, querying, indexing, transaction management and failure handling. We also refer to the problem of data integration and protection as data requires to be fit in single layout and travel securely as they arrive in the pool from diversified sources in different structure. Finally, we confer a standardized pathway to manage and to defend data in consistent manner.
Interactive Technologies for Improving Quality of Education to Build Collabor...ijsrd.com
Today with advancement in Information Communication Technology (ICT) the way the education is being delivered is seeing a paradigm shift from boring classroom lectures to interactive applications such as 2-D and 3-D learning content, animations, live videos, response systems, interactive panels, education games, virtual laboratories and collaborative research (data gathering and analysis) etc. Engineering is emerging with more innovative solutions in the field of education and bringing out their innovative products to improve education delivery. The academic institutes which were once hesitant to use such technology are now looking forward to such innovations. They are adopting the new ways as they are realizing the vast benefits of using such methods and technology. The benefits are better comprehensibility, improved learning efficiency of students, and access to vast knowledge resources, geographical reach, quick feedback, accountability and quality research. This paper focuses on how engineering can leverage the latest technology and build a collaborative learning environment which can then be integrated with the national e-learning grid.
Internet of Things - Paradigm Shift of Future Internet Application for Specia...ijsrd.com
In the world more than 15% people are living with disability that also include children below age of 10 years. Due to lack of independent support services specially abled (handicap) people overly rely on other people for their basic needs, that excludes them from being financially and socially active. The Internet of Things (IoT) can give support system and a better quality of life as well as participation in routine and day to day life. For this purpose, the future solutions for current problems has been introduced in this paper. Daunting challenges have been considered as future research and glimpse of the IoT for specially abled person is given in the paper.
A Study of the Adverse Effects of IoT on Student's Lifeijsrd.com
Internet of things (IoT) is the most powerful invention and if used in the positive direction, internet can prove to be very productive. But, now a days, due to the social networking sites such as Face book, WhatsApp, twitter, hike etc. internet is producing adverse effects on the student life, especially those students studying at college Level. As it is rightly said, something which has some positive effects also has some of the negative effects on the other hand. In this article, we are discussing some adverse effects of IoT on student’s life.
Pedagogy for Effective use of ICT in English Language Learningijsrd.com
The use of information and communications technology (ICT) in education is a relatively new phenomenon and it has been the educational researchers' focus of attention for more than two decades. Educators and researchers examine the challenges of using ICT and think of new ways to integrate ICT into the curriculum. However, there are some barriers for the teachers that prevent them to use ICT in the classroom and develop supporting materials through ICT. The purpose of this study is to examine the high school English teachers’ perceptions of the factors discouraging teachers to use ICT in the classroom.
In recent years usage of private vehicles create urban traffic more and more crowded. As result traffic becomes one of the important problems in big cities in all over the world. Some of the traffic concerns are traffic jam and accidents which have caused a huge waste of time, more fuel consumption and more pollution. Time is very important parameter in routine life. The main problem faced by the people is real time routing. Our solution Virtual Eye will provide the current updates as in the real time scenario of the specific route. This research paper presents smart traffic navigation system, based on Internet of Things, which is featured by low cost, high compatibility, easy to upgrade, to replace traditional traffic management system and the proposed system can improve road traffic tremendously.
Ontological Model of Educational Programs in Computer Science (Bachelor and M...ijsrd.com
In this work there is illustrated an ontological model of educational programs in computer science for bachelor and master degrees in Computer science and for master educational program “Computer science as second competence†by Tempus project PROMIS.
Understanding IoT Management for Smart Refrigeratorijsrd.com
1) The document discusses a proposed design for an intelligent refrigerator that leverages sensor technology and wireless communication to identify food items and order more through an internet connection when supplies are low.
2) Key aspects of the proposal include using RFID to uniquely identify each food item, storing item and usage data in an XML database, monitoring usage patterns to determine reordering needs, and executing orders through an online retailer using stored payment details.
3) Security and privacy concerns with such an internet-connected refrigerator are discussed, such as potential hacking of personal information or unauthorized device control. The proposal aims to minimize human interaction for household management.
DESIGN AND ANALYSIS OF DOUBLE WISHBONE SUSPENSION SYSTEM USING FINITE ELEMENT...ijsrd.com
Double wishbone designs allow the engineer to carefully control the motion of the wheel throughout suspension travel. 3-D model of the Lower Wishbone Arm is prepared by using CAD software for modal and stress analysis. The forces and moments are used as the boundary conditions for finite element model of the wishbone arm. By using these boundary conditions static analysis is carried out. Then making the load as a function of time; quasi-static analysis of the wishbone arm is carried out. A finite element based optimization is used to optimize the design of lower wishbone arm. Topology optimization and material optimization techniques are used to optimize lower wishbone arm design.
A Review: Microwave Energy for materials processingijsrd.com
Microwave energy is a latest largest growing technique for material processing. This paper presents a review of microwave technologies used for material processing and its use for industrial applications. Advantages in using microwave energy for processing material include rapid heating, high heating efficiency, heating uniformity and clean energy. The microwave heating has various characteristics and due to which it has been become popular for heating low temperature applications to high temperature applications. In recent years this novel technique has been successfully utilized for the processing of metallic materials. Many researchers have reported microwave energy for sintering, joining and cladding of metallic materials. The aim of this paper is to show the use of microwave energy not only for non-metallic materials but also the metallic materials. The ability to process metals with microwave could assist in the manufacturing of high performance metal parts desired in many industries, for example in automotive and aeronautical industries.
Web Usage Mining: A Survey on User's Navigation Pattern from Web Logsijsrd.com
With an expontial growth of World Wide Web, there are so many information overloaded and it became hard to find out data according to need. Web usage mining is a part of web mining, which deal with automatic discovery of user navigation pattern from web log. This paper presents an overview of web mining and also provide navigation pattern from classification and clustering algorithm for web usage mining. Web usage mining contain three important task namely data preprocessing, pattern discovery and pattern analysis based on discovered pattern. And also contain the comparative study of web mining techniques.
APPLICATION OF STATCOM to IMPROVED DYNAMIC PERFORMANCE OF POWER SYSTEMijsrd.com
Application of FACTS controller called Static Synchronous Compensator STATCOM to improve the performance of power grid with Wind Farms is investigated .The essential feature of the STATCOM is that it has the ability to absorb or inject fastly the reactive power with power grid . Therefore the voltage regulation of the power grid with STATCOM FACTS device is achieved. Moreover restoring the stability of the power system having wind farm after occurring severe disturbance such as faults or wind farm mechanical power variation is obtained with STATCOM controller . The dynamic model of the power system having wind farm controlled by proposed STATCOM is developed . To validate the powerful of the STATCOM FACTS controller, the studied power system is simulated and subjected to different severe disturbances. The results prove the effectiveness of the proposed STATCOM controller in terms of fast damping the power system oscillations and restoring the power system stability.
Making model of dual axis solar tracking with Maximum Power Point Trackingijsrd.com
Now a days solar harvesting is more popular. As the popularity become higher the material quality and solar tracking methods are more improved. There are several factors affecting the solar system. Major influence on solar cell, intensity of source radiation and storage techniques The materials used in solar cell manufacturing limit the efficiency of solar cell. This makes it particularly difficult to make considerable improvements in the performance of the cell, and hence restricts the efficiency of the overall collection process. Therefore, the most attainable maximum power point tracking method of improving the performance of solar power collection is to increase the mean intensity of radiation received from the source used. The purposed of tracking system controls elevation and orientation angles of solar panels such that the panels always maintain perpendicular to the sunlight. The measured variables of our automatic system were compared with those of a fixed angle PV system. As a result of the experiment, the voltage generated by the proposed tracking system has an overall of about 28.11% more than the fixed angle PV system. There are three major approaches for maximizing power extraction in medium and large scale systems. They are sun tracking, maximum power point (MPP) tracking or both.
A REVIEW PAPER ON PERFORMANCE AND EMISSION TEST OF 4 STROKE DIESEL ENGINE USI...ijsrd.com
This document summarizes a review paper on performance and emission testing of a 4-stroke diesel engine using ethanol-diesel blends at different pressures. The paper reviews several previous studies that tested blends of 5-30% ethanol mixed with diesel fuel. The studies found that a 10-20% ethanol blend can improve brake thermal efficiency compared to pure diesel, while also reducing emissions like NOx and smoke. Higher ethanol blends required advancing the injection timing to allow the engine to run. Ethanol-diesel blends were found to have lower density, viscosity, pour point and higher flash point compared to pure diesel. Overall, ethanol shows potential as a renewable fuel to improve engine performance and reduce emissions when blended with diesel
Study and Review on Various Current Comparatorsijsrd.com
This paper presents study and review on various current comparators. It also describes low voltage current comparator using flipped voltage follower (FVF) to obtain the single supply voltage. This circuit has short propagation delay and occupies a small chip area as compare to other current comparators. The results of this circuit has obtained using PSpice simulator for 0.18 μm CMOS technology and a comparison has been performed with its non FVF counterpart to contrast its effectiveness, simplicity, compactness and low power consumption.
Reducing Silicon Real Estate and Switching Activity Using Low Power Test Patt...ijsrd.com
Power dissipation is a challenging problem for today's system-on-chip design and test. This paper presents a novel architecture which generates the test patterns with reduced switching activities; it has the advantage of low test power and low hardware overhead. The proposed LP-TPG (test pattern generator) structure consists of modified low power linear feedback shift register (LP-LFSR), m-bit counter, gray counter, NOR-gate structure and XOR-array. The seed generated from LP-LFSR is EXCLUSIVE-OR ed with the data generated from gray code generator. The XOR result of the sequence is single input changing (SIC) sequence, in turn reduces the switching activity and so power dissipation will be very less. The proposed architecture is simulated using Modelsim and synthesized using Xilinx ISE9.2.The Xilinx chip scope tool will be used to test the logic running on FPGA.
Defending Reactive Jammers in WSN using a Trigger Identification Service.ijsrd.com
In the last decade, the greatest threat to the wireless sensor network has been Reactive Jamming Attack because it is difficult to be disclosed and defend as well as due to its mass destruction to legitimate sensor communications. As discussed above about the Reactive Jammers Nodes, a new scheme to deactivate them efficiently is by identifying all trigger nodes, where transmissions invoke the jammer nodes, which has been proposed and developed. Due to this identification mechanism, many existing reactive jamming defending schemes can be benefited. This Trigger Identification can also work as an application layer .In this paper, on one side we provide the several optimization problems to provide complete trigger identification service framework for unreliable wireless sensor networks and on the other side we also provide an improved algorithm with regard to two sophisticated jamming models, in order to enhance its robustness for various network scenarios.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
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.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
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.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
1. IJSRD - International Journal for Scientific Research & Development| Vol. 1, Issue 9, 2013 | ISSN (online): 2321-0613
All rights reserved by www.ijsrd.com 1741
Analysis on a Waveguide Mode Converter
P.D.Kanani1
V. M. Unadkat2
S. P. Dave3
1, 2, 3
Assistant Professor
1, 2, 3
Department of Electronics and Communication Engineering
1, 2
Atmiya institute of Technology and Science, Rajkot, Gujarat, India
3
SVIT,Vasad, Gujarat, INDIA
Abstract—There is a mainly two types of waveguide which
are mainly used in microwave transmission. A Rectangular
waveguide and a circular waveguide. Microwave
Propagation is being through these waveguides via different
modes at different frequencies. But in practical
implementation many problems arise like an ascetic
excitation method, efficiency of particular mode, complex
calculation etc., and an alternation is used. It is called a
waveguide converter. In this paper different types of
methods are analyzed and describe an output of these
methods.
Key words: Rectangular waveguide, circular waveguide,
Mode converter, Excitation method
I. INTRODUCTION
Waveguide is a metallic structure which is used for a
transmission of an electromagnetic energy between two
points. There are basically two types of waveguide. A metal
waveguide and a dielectric waveguide. Metal waveguides
are typically one enclosed conductor in which an insulating
medium is filled while a dielectric waveguide consists of
multiple dielectrics. For analysis of Waveguide we can use
appropriate coordinate systems according to geometrical
structure. For Example Rectangular wave guide is analogies
with Cartesian coordinate system and a circular waveguide
is analogies with cylindrical coordinate system
Electromagnetic wave consists of two components
one is electric field and other is magnetic fields. Direction
within a waveguide or transmission line decides a mode of
Propagation. If both E and H field are transverse to the
direction of propagation it called a TEM (Transverse electric
and magnetic) mode, if only E field is transverse to direction
of propagation it is a TE (Transverse Electric) mode and if
only H field is transverse to direction of propagation it is
TM (Transverse Magnetic)mode. This transverse component
can determine only from axial component of E and H using
“Maxwell’s Wave Equations”. Using these equations, in a
waveguide when E and H both field are transverse All
component of E and H become a Zero means there is no
TEM mode in a waveguide only TE and TM mode are exist
.one more important thing is that in unbounded transmission
we can consider a Component Ex, Ey, Hx and Hy to be
infinite or a long enough, but in a Bounded transmission
means in a waveguide this could not be assumed so
propagation constant which is consist of attenuation constant
and phase constant ( ϒ=α+jβ ) can describe in terms of some
frequency limit, so frequency below these make a
propagation constant ϒ pure real so wave are completely
attenuate means there is no propagation in short low
frequency cannot be transmit through waveguide and a
frequency limit is called a “Cut-Off frequency fc,mn” of that
waveguide. And for each specify waveguide structure by
putting a value of m and n we can determine a cut-off
frequency for an each mode. Out of number of mode
available a mode which is first to propagate is called a
“dominant mode”.
II. NECESSITIES OF CONVERSATION
Base on geometry structure we are differentiating a
waveguide like Rectangular waveguide, square waveguide,
circular waveguide, elliptical waveguide, truncated
waveguide, flexible waveguide etc. each of these have a
different operating mode .it means it’s not true always that
operating mode of one waveguide is same for any other
waveguide. So as per requirement, performances criteria,
and application point of view we need to convert this mode.
Some of the reasons for mode conversation are
listed below.
The mode transformation from the fundamental
TE10 mode in rectangular waveguide to the TE01 mode in
circular waveguide is of practical importance especially
where there is a necessity for long transmission runs or in
the case where high frequency operation is required [2].
In an application like a VLA (very large array)
radio telescope prime requirement is of level of losses
attenuation is very low. Therefore helical coupler can
utilize for direct conversation of TE01 mode of circular
waveguide from standard millimeter Rectangular waveguide
[3].TE01 mode in circular waveguide have a very low loss.
The generation of high order modes in circular
waveguide is useful for some applications. For example,
TM01, TE21 and TE01 modes excited in circular waveguide
are used in tracking feed subsystem for producing deference
pattern. In addition, several high power microwave
(HPM),Generators such as the oscillators of virtual cathode
(vircators), the Relativists backward wave oscillators from
reflected waves (BWOs) and The magnetically insulating
transmission-line oscillators (MILOs),Generate azimuthally
symmetric output modes with the TM01 circular Waveguide
mode and even the coaxial line transverse electromagnetic
Mode TEM. If these modes are directly radiated to the space
from The waveguides output, a doughnut-shaped radiation
pattern will be Produced, with a clear absence of signal in
the axis (bore-sight) Due to the fact that the transverse
electric field is null in the axis (Undesirable conical
radiation pattern)[1]
One of the available methods for converting a
mode from TE10 in Rectangular waveguide to Circular
waveguide is Marie converter. Reason to implication of
Marie converter is that, Marie converter was predominantly
based on ease of fabrication as fundamentally the geometric
2. Analysis on a Waveguide Mode Converter
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inner structure of the device is merely a series of straight
lines allowing it to be formed using the technique of wire
erosion [2].
Mode transformers are also used in antenna
applications for multimode antennas. These antennas have
different properties depending on spectra and phase shift of
radiated modes such as side and main lobe suppression,
directivity and polarization change [4].
A Travelling wave Tube (TWT) is a vacuum tube
that is used to amplify a signal at a high frequency. Input
coupling system is an important part of the gyro-TWT. Its
main function is that the input signal is coupled to Gyro-
TWT interaction circuit, while the operating mode transition
from input mode. Input coupling circuit will have a direct
impact on gyro-TWT performance [5].
A wideband input coupling system is presented
which realize the conversion from the input rectangular
waveguide TE10 mode to operating mode TE11 (circular
polarized) [5].
Due to the problem of circular waveguide in the
excitation process, in this paper, a rectangular to circular
waveguide converter is proposed as an alternative method to
excite the circular waveguide from rectangular transducer
[6]
An ULTRA-HIGH-POWER RF system such as
linear colliders where hundreds of megawatts of pulsed RF
power is manipulated, over-moded waveguides are widely
used to increase the power-handling capacity. Losses in the
system are minimized by transporting power in circular
waveguides in azimuthally symmetric modes such as the
mode. In many instances, the RF power is easier to
manipulate in rectangular waveguides than in circular
waveguides [7].
Due to the development of high-power, high-
frequency gyrotrons, there was considerable interest in
mode converters to transform the higher order modes of a
circular waveguide to the lower order, lower loss H01mode.
Mode H01in, its turn, can be transformed into the first mode
H11which has the radiation pattern with good directivity [4].
Transitions from square to circular waveguides are required
in measurement of ceramic used in gyrotrons beam tunnel
and RF window [9].
The TM01 circular waveguide (CWG) mode is
generated by sources with axial Electron beams, which are
most of the very high power (>Megawatt) sources. This
mode has a Transverse electric field null on the axis,
producing a donut-shaped beam when radiated rather than
the preferred solid beam. The desired mode is the TEl1.In
order to best use these power sources, it is necessary to
convert the TM01 mode to theTE11 CWG mode. [10].
Transmission loss of the oversize Waveguide is lower than
that of the beam Waveguide at 141 Gc [11].
III. DESIGN METHODOLOGIES
As discussed above each specific waveguide can operate
over many different available TE and TM mode. Out of
these dominant modes of Rectangular wave guide has a
TE10 and circular waveguide has a TE11 mode.
Method: 1A.
Due to the fact that in a circular waveguide the TM01 mode
has a higher cutoff frequency higher than the fundamental
TE11 mode, it is impossible to make the direct conversion
without any reaction in the signal to be transmitted. The
mechanical alternative proposed in this work initially
allows the conversion of the TM01 mode of the circular
waveguide to the TEM coaxial transmission line mode,
which has a cutoff frequency equal to zero. This philosophy
divides the design into two parts: the first part transforms
the TM01 circular mode towards the TEM coaxial mode,
and the second one transforms the TEM mode to the TE11
circular mode. Unfortunately, the conversion TEM-TE11
cannot be obtained.
In wide band, due to the proximity between The
cutoff frequencies of the two modes, TM01 and TE11
circular waveguide modes. Therefore, the second part was
realized using an intermediate mode TE10 of rectangular
waveguide; therefore, it was necessary to design an axial
intermediate TEM-TE10 converter that was feeding a later
TE10-TE11 [1]. Subsequently, a transition between the
coaxial line and rectangular waveguide will be designed
using a septum of at least three sections, which allows a
high TEM-TE10 conversion efficiency in a frequency
bandwidth superior to 55%.an octagonal intermediate
Transition from a rectangular to a circular waveguide, which
allows a TE10-TE11 conversion in a frequency bandwidth
of an octave with no evidence of higher order mode
excitation [1].
Fig. 1: Mode converter internal view and the propagated
fundamental mode in various waveguide sections [1]
Method: 2B.
For converting a mode from TE10 of Rectangular to TE01
of Circular waveguide can perform by a Marie converter
.The Marie converter comprises of three main sections and
this model can simulated in the VE Studio, The decision to
model a Marie converter was predominantly based on ease
of fabrication as fundamentally the geometric Inner structure
of the device is merely a series of straight lines allowing it
to be formed using the Technique of wire erosion [2].
Method: 3C.
The TE10 rectangular waveguide mode is converted to the
circular polarization TE11 circular waveguide mode, the
pill-box window of the vacuum envelope is used, A
common technique for producing circular polarization mode
is that two equal amplitude but 90°phase shifted linear
polarization signals simultaneously injected from two
directions perpendicular to the circular waveguide.
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The main difficulty of this approach is that two
signals is hard to maintain the same size and phase to
maintain 90 ° in a certain bandwidth [5].every mode
converter has a main task to design a transaction region
which convert a mode of input to output. But here output
mode have a circular polarization so to obtain this, Mode
converter circuit of this design consist of a rectangular
waveguide, Elliptical waveguide section and electron beam
channel [5].
Method: 4D.
Conversion of mode between a TE10 of rectangular to TE11
mode of a circular waveguide can be possible by
constitution of a metallic geometric structure. Its one end
will be open at an output port of a rectangular waveguide
and second end would be at input port of a circular
waveguide. This is called a transition region. 5. The
minimum length of transition should be quarter wavelength
to avoid abrupt dimensional changes and generation of
higher order modes [6].
Method: 5E.
Fig. 1 shows a photograph of a Marie transducer next to the
Compact mode converter developed at SLAC. The compact
Mode converter shown in Figure I.2 is made of five sections
and Converts a circular waveguide mode to a rectangular
waveguide mode. The first section of the compact mode
converter is a height taper that connects a standard
rectangular waveguide with dimensions 3.05 cm 2.32 cm.
Section 2 is straight section rectangular waveguide that
connects to a nonuniform waveguide made of three sections.
The design methodology of sections 1 and 2 is given in [6].
The three-section nonuniform waveguide shown
schematically in Fig. 2 converts a rectangular waveguide
mode to a circular waveguide mode. Due to structural
symmetry, these three sections can also convert a
rectangular waveguide mode to a circular waveguide mode.
The length of these three-section part of the mode converter
is less than 7.63 cm in), while a corresponding Marie mode
converter, which can convert the same modes, will be
around 0.457 m (18 in) long [7].
Fig. 2: Compact mode converter fabricated at SLAC and the
Marie mode [7].
Method: 6F.
The basic transformer in Figure 3 contains an on-axis
Connection of one square and one circular Waveguide
section. The other circular section is introduced for further
return-loss improvement. Although the relationships of the
fundamental mode cut-off frequencies in square and circular
waveguides generally vary for different designs, the
following initial dimensions have been broadly tested and
will commonly yield a return loss of better than 20 dB. In
the design procedure of square-to-circular transitions, we
first assume that all transformer sections be Circular as
shown in the Figure 3. The diameters of the circular sections
can now be related to a. where is the dimension of square
waveguide. The diameters can equal the width/height of the
square design, i.e., d =a. combination of a (i) and b (i) can
be used to determine the diameters. In order to limit the
influence of the rather large b dimensions, we choose the
diameter of circular waveguide equal to the diagonal of the
square Waveguide [9]. The fine optimization is carried out
using the Mode-Matching Technique (MMT), the diameters
and lengths of the circular sections between the square input
and the circular output guide are optimized using a Mini-
Max based algorithm the function to be minimized is given
by [9]
∑ [ ] (3.1)
Where Rn and R (f) are the desired and actual Return loss,
respectively, at frequency fi [9].
Fig. 3: 22.86X22.86 square to 13.5 mm diameter circular
transition with 4.4 mm transformer length [7].
IV. COMMENTS ON PERFORMANCES
As discussed above out of available many methods,
selection of method depends on application point of view.
Because every method has its own merits and demerits.
Fig. 4: Simulated and measured output TE11 circular
reflection of The TM01 to TE11 mode converter [1]
For Example if larger bandwidth is require method 1 is
suitable. it give a the return losses are in the order of 28 dB
in both modes TM01 and TE11 along with measured
insertion losses less than 0.1 dB, giving rise to a conversion
efficiency of 98.8% in a fractional bandwidth superior to
55% [1].S-parameter are as shown in below diagram Figure
4 and Figure 5. Technique used in method 3 has
conversation efficiency of 83% and more in frequency range
of 34-36 GHz [5] as shown in figure 6.
4. Analysis on a Waveguide Mode Converter
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Fig. 5: Simulated and measured input TM01 circular
reflection of the TM01 to TE11 mode converter [1].
Fig. 6: Transmission Coefficient versus frequency obtained
from a HSFF simulation [5].
Minimum length of transaction should be quarter
wavelength to avoid abrupt dimensional change and
generation of higher order mode [6]. Return loss for
different length of transition region is as a shown in figure 7.
Fig. 7: Return loss of different lengths of transition segment
[6].
Figure 8 shows the scattering parameters of the two mode
converters tested back to back. This is design by a help of
method 5. Indeed, the device has a near-perfect performance
at the design frequency of 11.424 GHz [7].
In a particular application where prime requirement
is a higher bandwidth can go through a method describe in
[10].because it give typical insertion loss of 0.25 dB and less
than 0.5 dB over a 30% bandwidth [10] as shown in Fig. 7.
Fig. 8: Parameters for two compact mode converters
connected back to back [7].
Fig. 9: Measured Insertion Loss for the L-band Mode
Convertor [10]
Square to circular waveguide mode converter which design
based on method 6 describe above has a 30 dB return loss is
achieved with transformer length is 4.4 mm [9].
Fig. 10: Performance of square to circular waveguide
Transformation according to Figure I.3 [9]
V. CONCLUSIONS AND FUTURE WORK
This paper is reported on study of different method of
converting a mode in waveguide, its Requirement and
application along with performances. This paper also
includes results of s-parameter diagram based on CST
microwave studio and HFSS. Based on application point of
view and requirement of performance enhancement of
particular parameter we can select a various method. In
future study we will try to derive a mathematical formula for
length transition region as a function of wavelength for C
band.
5. Analysis on a Waveguide Mode Converter
(IJSRD/Vol. 1/Issue 9/2013/0012)
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