The document compares the performance of uniform line arrays using non-overlapping (NOSA) and overlapping (2:1 OSA, 3:1 OSA) subarray architectures with conventional beamforming (CBF) and adaptive beamforming (ABF). Key results show that increasing the overlap factor reduces the number and amplitude of grating lobes when beams are steered off broadside. Specifically, the 3:1 OSA architecture showed grating lobe levels 42 dB below the main lobe compared to 12 dB for NOSA and 25 dB for 2:1 OSA. For ABF, the different architectures performed identically due to their equivalent K/I ratios, but increasing overlap thinned the grating lobes at higher SNR
This document contains solutions to multiple physics problems involving electromagnetic waves. Problem 1 involves calculating the conductivity and penetration depth of graphite at different frequencies. Problem 2 involves propagating an electromagnetic wave in seawater and calculating various parameters like attenuation constant and phase velocity. It provides the solutions and steps for parts a, b, and c of this problem. Problem 3 involves analyzing the behavior of electromagnetic waves on a finite transmission line terminated by a load impedance and derives relevant equations.
EE402B Radio Systems and Personal Communication Networks-Formula sheetHaris Hassan
Programmes in which available:
Masters of Engineering - Electrical and Electronic
Engineering. Masters of Engineering - Electronic
Engineering and Computer Science. Master of Science -
Communication Systems and Wireless Networking.
Master of Science - Smart Telecom and Sensing
Networks. Master of Science - Photonic Integrated
Circuits, Sensors and Networks
To enable an extension of knowledge in fundamental data communications to radio communications and networks widely adopted
in modern telecommunications systems. To provide understanding of radio wave utilisation, channel loss properties, mobile
communication technologies and network protocol architecture applied to practical wireless systems
EE402B Radio Systems and Personal Communication Networks notesHaris Hassan
Programmes in which available:
Masters of Engineering - Electrical and Electronic
Engineering. Masters of Engineering - Electronic
Engineering and Computer Science. Master of Science -
Communication Systems and Wireless Networking.
Master of Science - Smart Telecom and Sensing
Networks. Master of Science - Photonic Integrated
Circuits, Sensors and Networks.
The document describes a simulation of an optical communication system using different modulation formats at bit rates of 10.7 Gbps and 42.65 Gbps. The system includes a transmitter with a laser, data source, modulator, and amplifier. A noisy channel is modeled by adding ASE noise. A receiver includes a filter, photodetector, amplifier, and error counting. Eye diagrams, spectra, and BER are analyzed for each modulation format under various channel conditions including OSNR and chromatic dispersion. The impact of increasing bandwidth for PSBT is also examined.
(1) The document discusses physics concepts related to magnetic fields, sound waves, orbital motion, heat transfer, electrostatics, and nuclear reactions.
(2) Multiple choice questions with one or more correct answers assess concepts like magnetic fields from current-carrying conductors and solenoids, Doppler effect of sound waves, orbital angular momentum and wavelength transitions in hydrogen-like atoms, heat absorption rates as a function of temperature, and electrostatic fields between overlapping charged spheres.
(3) Paragraph questions provide contexts for circular motion down an inclined plane with friction, step-up and step-down power transmission using transformers, and nuclear binding energy and the conditions for nuclear fusion and fission reactions.
(1) The document provides conceptual problems and their solutions related to oscillations and simple harmonic motion. (2) It examines the kinetic and potential energy of an object undergoing simple harmonic motion with a given amplitude. (3) It compares the maximum speeds of two simple harmonic oscillators with identical amplitudes but different masses attached to identical springs.
The document summarizes problems from Chapter 15 of a physics textbook about traveling waves.
1. A pulse sent up a vertical rope will travel faster as it moves toward the ceiling because the tension in the rope increases due to the weight of the rope below the pulse.
2. Using strings with different linear mass densities allows a piano manufacturer to use strings with lengths that are all the same order of magnitude by accommodating extremely high frequencies on relatively short strings.
3. If two sound waves have the same amplitude but one frequency is twice the other, the average energy density of the higher frequency sound is four times that of the lower frequency sound.
This document contains solutions to multiple physics problems involving electromagnetic waves. Problem 1 involves calculating the conductivity and penetration depth of graphite at different frequencies. Problem 2 involves propagating an electromagnetic wave in seawater and calculating various parameters like attenuation constant and phase velocity. It provides the solutions and steps for parts a, b, and c of this problem. Problem 3 involves analyzing the behavior of electromagnetic waves on a finite transmission line terminated by a load impedance and derives relevant equations.
EE402B Radio Systems and Personal Communication Networks-Formula sheetHaris Hassan
Programmes in which available:
Masters of Engineering - Electrical and Electronic
Engineering. Masters of Engineering - Electronic
Engineering and Computer Science. Master of Science -
Communication Systems and Wireless Networking.
Master of Science - Smart Telecom and Sensing
Networks. Master of Science - Photonic Integrated
Circuits, Sensors and Networks
To enable an extension of knowledge in fundamental data communications to radio communications and networks widely adopted
in modern telecommunications systems. To provide understanding of radio wave utilisation, channel loss properties, mobile
communication technologies and network protocol architecture applied to practical wireless systems
EE402B Radio Systems and Personal Communication Networks notesHaris Hassan
Programmes in which available:
Masters of Engineering - Electrical and Electronic
Engineering. Masters of Engineering - Electronic
Engineering and Computer Science. Master of Science -
Communication Systems and Wireless Networking.
Master of Science - Smart Telecom and Sensing
Networks. Master of Science - Photonic Integrated
Circuits, Sensors and Networks.
The document describes a simulation of an optical communication system using different modulation formats at bit rates of 10.7 Gbps and 42.65 Gbps. The system includes a transmitter with a laser, data source, modulator, and amplifier. A noisy channel is modeled by adding ASE noise. A receiver includes a filter, photodetector, amplifier, and error counting. Eye diagrams, spectra, and BER are analyzed for each modulation format under various channel conditions including OSNR and chromatic dispersion. The impact of increasing bandwidth for PSBT is also examined.
(1) The document discusses physics concepts related to magnetic fields, sound waves, orbital motion, heat transfer, electrostatics, and nuclear reactions.
(2) Multiple choice questions with one or more correct answers assess concepts like magnetic fields from current-carrying conductors and solenoids, Doppler effect of sound waves, orbital angular momentum and wavelength transitions in hydrogen-like atoms, heat absorption rates as a function of temperature, and electrostatic fields between overlapping charged spheres.
(3) Paragraph questions provide contexts for circular motion down an inclined plane with friction, step-up and step-down power transmission using transformers, and nuclear binding energy and the conditions for nuclear fusion and fission reactions.
(1) The document provides conceptual problems and their solutions related to oscillations and simple harmonic motion. (2) It examines the kinetic and potential energy of an object undergoing simple harmonic motion with a given amplitude. (3) It compares the maximum speeds of two simple harmonic oscillators with identical amplitudes but different masses attached to identical springs.
The document summarizes problems from Chapter 15 of a physics textbook about traveling waves.
1. A pulse sent up a vertical rope will travel faster as it moves toward the ceiling because the tension in the rope increases due to the weight of the rope below the pulse.
2. Using strings with different linear mass densities allows a piano manufacturer to use strings with lengths that are all the same order of magnitude by accommodating extremely high frequencies on relatively short strings.
3. If two sound waves have the same amplitude but one frequency is twice the other, the average energy density of the higher frequency sound is four times that of the lower frequency sound.
This paper proposes and analyzes the performance of a selection decode-and-forward cooperative free-space optical communication system using adaptive subcarrier quadrature amplitude modulation. The system employs selective relaying to choose the best intermediate node based on channel state information. Novel expressions are derived for outage probability, spectral efficiency, and bit error rate considering Gamma-Gamma atmospheric turbulence fading. Numerical results show that the proposed adaptive system has improved performance compared to non-adaptive systems and all-active relaying schemes.
This document discusses amplitude modulated communication systems. It describes how a carrier signal is modulated by a baseband modulating signal to allow for information exchange over a channel. There are different types of modulation including continuous wave, pulse, and digital modulation. Amplitude modulation varies the amplitude of the carrier signal based on the instantaneous value of the modulating signal. This allows for multiplexing of multiple messages and use of more practical antenna sizes. Specific amplitude modulation techniques are described like conventional AM, DSB-SC, SSB, and VSB along with their tradeoffs in terms of carrier suppression, bandwidth, cost, and applications.
On The Fundamental Aspects of DemodulationCSCJournals
When the instantaneous amplitude, phase and frequency of a carrier wave are modulated with the information signal for transmission, it is known that the receiver works on the basis of the received signal and a knowledge of the carrier frequency. The question is: If the receiver does not have the a priori information about the carrier frequency, is it possible to carry out the demodulation process? This tutorial lecture answers this question by looking into the very fundamental process by which the modulated wave is generated. It critically looks into the energy separation algorithm for signal analysis and suggests modification for distortionless demodulation of an FM signal, and recovery of sub-carrier signals
This document proposes a new SAR superresolution imaging algorithm based on adaptive sidelobe reduction (ASR). It outlines issues with conventional weighting methods and describes how the new algorithm uses ASR to suppress sidelobes without degrading resolution. Simulation results show the new method improves resolution and lowers sidelobes compared to conventional Fourier techniques.
This document discusses single sideband (SSB) modulation. It begins by reviewing double sideband suppressed carrier (DSB-SC) modulation and how SSB modulation is derived from DSB-SC by suppressing one of the sidebands. It then provides the mathematical expressions for upper SSB and lower SSB modulation. The document also covers the Hilbert transform and how it relates to SSB modulation. It describes the spectra of upper and lower SSB signals and two methods for modulating SSB: frequency discrimination and phase discrimination. Finally, it discusses demodulation of SSB signals.
The document summarizes the one-way radar equation used in radar warning receiver (RWR) or electronic support measure (ESM) applications. It describes:
1) The one-way radar equation relates the power density from a radar transmitter to the received power at a distant antenna based on factors like transmitter power, antenna gains, wavelength, and distance.
2) Received signal power decreases by 6 dB for each doubling of distance due to the inverse square law.
3) The one-way free space loss factor, which represents signal attenuation over distance, is calculated and examples are provided to determine the loss at specific frequencies and ranges.
This document summarizes a study measuring the transverse beam emittance at the Energy Selection System (ESS) of the KIRAMS-430 superconducting cyclotron. The researchers used a quadrupole variation method, where they varied the magnetic strength of a quadrupole magnet and measured the resulting beam size at a beam profile monitor. They analyzed the measurements using both linear matrix formalism and particle tracking simulations. The results from both analysis methods were consistent with emittances calculated from Monte Carlo simulations within the measurement uncertainties. The study demonstrated the feasibility of using the quadrupole variation method to characterize the beam quality at the ESS ion beamline.
1. The document provides conceptual problems and solutions related to superposition and standing waves. It discusses topics like wave pulses traveling in opposite directions, fundamental frequencies of open and closed organ pipes, and using resonance frequencies to estimate air temperature.
2. It also covers problems involving interference of two waves with different phases and frequencies, and deriving an expression for the envelope of a superposed wave.
3. For one problem, it plots the total displacement of a superposed wave at t=0, and the envelope function at t=0, 5, and 10 seconds. From these plots, it estimates the speed of the envelope and compares it to the theoretical value obtained from the problem parameters.
Design of Tripl-Band CPW FED Circular Fractal Antenna ijcisjournal
A novel miniaturized circular fractal antenna is designed by inscribing circular slot on rectangular ground
plane and successively forming circular rings connected by semi-circles for circular-fractal patch. Novel
modified Coplanar Waveguide (CPW) is used as feed for fractal circular patch. The analysis of parametric
variations is performed by consecutive fractal iterations, varying the radius of inscribed circle of ground
plane, slots and different ground plane configurations. To further enhance gain and radiation pattern a
dual inverted L slots is included in ground plane. From the results it is evident that, the proposed fractal
antenna possesses triple bands at 1.8GHz, 3.5GHz and 5.5GHz. These bands are used in Digital
Communication Systems (DCS) (1.8GHz), IEEE 802.16d fixed WiMAX (3.5GHz) and IEEE 802.11a WLAN
(5.5GHz) applications.
Presentation on the normalization channelsRuturaj Apte
This document describes a search for the semileptonic B decay channel B->D(*)ππlν in BaBar data. Key steps included reconstructing a Btag meson, using normalization modes to reduce uncertainties, applying a multivariate Fisher analysis to improve signal-to-background ratio, and fitting the (missing mass)2 distribution to extract signal yields. Preliminary results were presented for normalization channels, with the next steps being to fit the Dππlν channel and calculate its branching fraction using a double ratio method.
This document describes using MATLAB to analyze a synthetic time series dataset representing climate data over 500,000 years. The time series contains periodic signals at 100ky, 41ky and 21ky. Random noise and a long term trend are added. Fourier analysis is used to identify the dominant periodic components in the frequency domain. A Hamming window and bandpass filter are applied to further analyze specific frequency bands like the 21ky signal. Autocorrelation is also examined to identify cyclic patterns in the time series.
The document describes DSB-SC (double sideband suppressed carrier) modulation. It discusses how a message signal is modulated by multiplying it with a carrier wave, removing the carrier. It shows the Fourier transform of the modulated signal has sidebands above and below the carrier frequency. Coherent detection is also summarized, where the received signal is multiplied by a local oscillator signal to recover the message signal, requiring synchronization of the receiver oscillator frequency and phase to the carrier.
Convergence Behaviour of Newton-Raphson Method in Node- and Loop-Based Non-li...balaganesh boomiraja
A simplified Jacobian is derived for both node- and loop-based magnetic equivalent circuit analysis. The partial derivative term is eliminated in this simplified Jacobian using differential relative permeability. The convergence behaviour of the Newton-Raphson method is studied. The loop analysis exhibits more stable convergence than that of the node analysis while solving non-linear magnetic equivalent circuit using the Newton-Raphson method.
1. VSB modulation is used for picture transmission in commercial TV in India as it provides a compromise between SSB and DSB. Speech signals use FM modulation for its noise immunity.
2. In a DSB AM system, if the modulation index is doubled, the ratio of sideband power to carrier power increases by a factor of 4.
3. The maximum power efficiency of an AM modulator is 33%.
The document investigates the impact of silicon carbide (SiC) polytype on the electronic structure of graphene epitaxial layers. It finds that the position of the Dirac point and Fermi level systematically shift with increasing hexagonality of the SiC polytype. Additionally, a gap of 30-40 meV is observed at the Dirac point, independent of the polytype. Low energy phonons at the SiC/graphene interface are also found to cause electron scattering by varying the separation between graphene and buffer layers, reducing graphene layer conductivity compared to suspended graphene. Calculations using the Boltzmann formalism are able to reproduce the experimentally observed temperature dependence of conductivity for different Fermi energies.
This document describes setting up torque equilibrium for a beam with weights on each end to solve for the unknown far end force. It finds the far end force is 1500 N. It then uses vertical force equilibrium to solve for the near end force, finding it to be 1900 N.
The document contains solutions to example problems from a mechanics of materials textbook. Solution 1 resolves a 90 N force into components and calculates the moment MB as -13.02 N⋅m. Solution 2 similarly resolves a force and calculates the moment MB. Solution 3 calculates the moment MA for a 3 lb force as 16.03 lb⋅in.
Digital Communication and Modulation
Project 3 “Satellite Link Budgets and PE”
Arlene Meidahl - s107106 and Danish Bangash-s104712| Digital Communication | 21. maj 2015
Supervisor: John Aasted Sørensen
Lecture Notes: EEEC6440315 Communication Systems - Spectral AnalysisAIMST University
1) The document discusses Fourier transforms and their applications in signal analysis and communication systems. It defines the direct and inverse Fourier transforms and their use in relating time and frequency domain representations of signals.
2) Modulation is described as a way to shift signal spectra to different frequency bands, allowing multiple signals to be transmitted simultaneously without interference. Common modulation techniques are discussed along with their effects on signal spectra.
3) Characteristics of linear time-invariant systems are outlined, defining how they affect input signals in both time and frequency domains. Distortion effects of non-linear systems are also covered.
4) Concepts of energy, energy spectral density, and essential bandwidth are defined in relation to signal frequency spectra.
This document discusses the design of singly reinforced concrete beams. It covers:
1) Concrete stress distribution and equivalent stress blocks. The depth and location of the neutral axis are defined.
2) Strength analysis using equilibrium of forces and moments. Flexural strength equations are developed.
3) Determination of steel ratios including balanced, maximum, and minimum ratios based on material strengths and code requirements.
4) Procedure to determine the flexural strength of a beam given its dimensions and material properties.
5) Method to calculate the required steel area to resist a given bending moment based on an iterative approach solving for the depth of the compression block.
Women's Running Magazine Subscription UK Offeryogisri001
Trikarana Transcendental Meditation (TTM)
Yogi Sriji is an enlightened spiritual leader; founder of Trikarana Yoga Charitable Trust and Trikarana Transcendental Meditation (TTM) Center, a unit of the Trust, started in the year 2009 in Coimbatore, an Industrial City in Tamil Nadu, India.
The document outlines a lesson plan on a topic, including the learning outcome, contents to be covered such as new terms and facts, classroom interaction procedures such as asking questions, and review questions at the end to assess understanding. It provides the structure and contents of the lesson to help teach the topic. The teacher is to go through the contents, engage students through questioning techniques, and evaluate learning through the review questions.
This paper proposes and analyzes the performance of a selection decode-and-forward cooperative free-space optical communication system using adaptive subcarrier quadrature amplitude modulation. The system employs selective relaying to choose the best intermediate node based on channel state information. Novel expressions are derived for outage probability, spectral efficiency, and bit error rate considering Gamma-Gamma atmospheric turbulence fading. Numerical results show that the proposed adaptive system has improved performance compared to non-adaptive systems and all-active relaying schemes.
This document discusses amplitude modulated communication systems. It describes how a carrier signal is modulated by a baseband modulating signal to allow for information exchange over a channel. There are different types of modulation including continuous wave, pulse, and digital modulation. Amplitude modulation varies the amplitude of the carrier signal based on the instantaneous value of the modulating signal. This allows for multiplexing of multiple messages and use of more practical antenna sizes. Specific amplitude modulation techniques are described like conventional AM, DSB-SC, SSB, and VSB along with their tradeoffs in terms of carrier suppression, bandwidth, cost, and applications.
On The Fundamental Aspects of DemodulationCSCJournals
When the instantaneous amplitude, phase and frequency of a carrier wave are modulated with the information signal for transmission, it is known that the receiver works on the basis of the received signal and a knowledge of the carrier frequency. The question is: If the receiver does not have the a priori information about the carrier frequency, is it possible to carry out the demodulation process? This tutorial lecture answers this question by looking into the very fundamental process by which the modulated wave is generated. It critically looks into the energy separation algorithm for signal analysis and suggests modification for distortionless demodulation of an FM signal, and recovery of sub-carrier signals
This document proposes a new SAR superresolution imaging algorithm based on adaptive sidelobe reduction (ASR). It outlines issues with conventional weighting methods and describes how the new algorithm uses ASR to suppress sidelobes without degrading resolution. Simulation results show the new method improves resolution and lowers sidelobes compared to conventional Fourier techniques.
This document discusses single sideband (SSB) modulation. It begins by reviewing double sideband suppressed carrier (DSB-SC) modulation and how SSB modulation is derived from DSB-SC by suppressing one of the sidebands. It then provides the mathematical expressions for upper SSB and lower SSB modulation. The document also covers the Hilbert transform and how it relates to SSB modulation. It describes the spectra of upper and lower SSB signals and two methods for modulating SSB: frequency discrimination and phase discrimination. Finally, it discusses demodulation of SSB signals.
The document summarizes the one-way radar equation used in radar warning receiver (RWR) or electronic support measure (ESM) applications. It describes:
1) The one-way radar equation relates the power density from a radar transmitter to the received power at a distant antenna based on factors like transmitter power, antenna gains, wavelength, and distance.
2) Received signal power decreases by 6 dB for each doubling of distance due to the inverse square law.
3) The one-way free space loss factor, which represents signal attenuation over distance, is calculated and examples are provided to determine the loss at specific frequencies and ranges.
This document summarizes a study measuring the transverse beam emittance at the Energy Selection System (ESS) of the KIRAMS-430 superconducting cyclotron. The researchers used a quadrupole variation method, where they varied the magnetic strength of a quadrupole magnet and measured the resulting beam size at a beam profile monitor. They analyzed the measurements using both linear matrix formalism and particle tracking simulations. The results from both analysis methods were consistent with emittances calculated from Monte Carlo simulations within the measurement uncertainties. The study demonstrated the feasibility of using the quadrupole variation method to characterize the beam quality at the ESS ion beamline.
1. The document provides conceptual problems and solutions related to superposition and standing waves. It discusses topics like wave pulses traveling in opposite directions, fundamental frequencies of open and closed organ pipes, and using resonance frequencies to estimate air temperature.
2. It also covers problems involving interference of two waves with different phases and frequencies, and deriving an expression for the envelope of a superposed wave.
3. For one problem, it plots the total displacement of a superposed wave at t=0, and the envelope function at t=0, 5, and 10 seconds. From these plots, it estimates the speed of the envelope and compares it to the theoretical value obtained from the problem parameters.
Design of Tripl-Band CPW FED Circular Fractal Antenna ijcisjournal
A novel miniaturized circular fractal antenna is designed by inscribing circular slot on rectangular ground
plane and successively forming circular rings connected by semi-circles for circular-fractal patch. Novel
modified Coplanar Waveguide (CPW) is used as feed for fractal circular patch. The analysis of parametric
variations is performed by consecutive fractal iterations, varying the radius of inscribed circle of ground
plane, slots and different ground plane configurations. To further enhance gain and radiation pattern a
dual inverted L slots is included in ground plane. From the results it is evident that, the proposed fractal
antenna possesses triple bands at 1.8GHz, 3.5GHz and 5.5GHz. These bands are used in Digital
Communication Systems (DCS) (1.8GHz), IEEE 802.16d fixed WiMAX (3.5GHz) and IEEE 802.11a WLAN
(5.5GHz) applications.
Presentation on the normalization channelsRuturaj Apte
This document describes a search for the semileptonic B decay channel B->D(*)ππlν in BaBar data. Key steps included reconstructing a Btag meson, using normalization modes to reduce uncertainties, applying a multivariate Fisher analysis to improve signal-to-background ratio, and fitting the (missing mass)2 distribution to extract signal yields. Preliminary results were presented for normalization channels, with the next steps being to fit the Dππlν channel and calculate its branching fraction using a double ratio method.
This document describes using MATLAB to analyze a synthetic time series dataset representing climate data over 500,000 years. The time series contains periodic signals at 100ky, 41ky and 21ky. Random noise and a long term trend are added. Fourier analysis is used to identify the dominant periodic components in the frequency domain. A Hamming window and bandpass filter are applied to further analyze specific frequency bands like the 21ky signal. Autocorrelation is also examined to identify cyclic patterns in the time series.
The document describes DSB-SC (double sideband suppressed carrier) modulation. It discusses how a message signal is modulated by multiplying it with a carrier wave, removing the carrier. It shows the Fourier transform of the modulated signal has sidebands above and below the carrier frequency. Coherent detection is also summarized, where the received signal is multiplied by a local oscillator signal to recover the message signal, requiring synchronization of the receiver oscillator frequency and phase to the carrier.
Convergence Behaviour of Newton-Raphson Method in Node- and Loop-Based Non-li...balaganesh boomiraja
A simplified Jacobian is derived for both node- and loop-based magnetic equivalent circuit analysis. The partial derivative term is eliminated in this simplified Jacobian using differential relative permeability. The convergence behaviour of the Newton-Raphson method is studied. The loop analysis exhibits more stable convergence than that of the node analysis while solving non-linear magnetic equivalent circuit using the Newton-Raphson method.
1. VSB modulation is used for picture transmission in commercial TV in India as it provides a compromise between SSB and DSB. Speech signals use FM modulation for its noise immunity.
2. In a DSB AM system, if the modulation index is doubled, the ratio of sideband power to carrier power increases by a factor of 4.
3. The maximum power efficiency of an AM modulator is 33%.
The document investigates the impact of silicon carbide (SiC) polytype on the electronic structure of graphene epitaxial layers. It finds that the position of the Dirac point and Fermi level systematically shift with increasing hexagonality of the SiC polytype. Additionally, a gap of 30-40 meV is observed at the Dirac point, independent of the polytype. Low energy phonons at the SiC/graphene interface are also found to cause electron scattering by varying the separation between graphene and buffer layers, reducing graphene layer conductivity compared to suspended graphene. Calculations using the Boltzmann formalism are able to reproduce the experimentally observed temperature dependence of conductivity for different Fermi energies.
This document describes setting up torque equilibrium for a beam with weights on each end to solve for the unknown far end force. It finds the far end force is 1500 N. It then uses vertical force equilibrium to solve for the near end force, finding it to be 1900 N.
The document contains solutions to example problems from a mechanics of materials textbook. Solution 1 resolves a 90 N force into components and calculates the moment MB as -13.02 N⋅m. Solution 2 similarly resolves a force and calculates the moment MB. Solution 3 calculates the moment MA for a 3 lb force as 16.03 lb⋅in.
Digital Communication and Modulation
Project 3 “Satellite Link Budgets and PE”
Arlene Meidahl - s107106 and Danish Bangash-s104712| Digital Communication | 21. maj 2015
Supervisor: John Aasted Sørensen
Lecture Notes: EEEC6440315 Communication Systems - Spectral AnalysisAIMST University
1) The document discusses Fourier transforms and their applications in signal analysis and communication systems. It defines the direct and inverse Fourier transforms and their use in relating time and frequency domain representations of signals.
2) Modulation is described as a way to shift signal spectra to different frequency bands, allowing multiple signals to be transmitted simultaneously without interference. Common modulation techniques are discussed along with their effects on signal spectra.
3) Characteristics of linear time-invariant systems are outlined, defining how they affect input signals in both time and frequency domains. Distortion effects of non-linear systems are also covered.
4) Concepts of energy, energy spectral density, and essential bandwidth are defined in relation to signal frequency spectra.
This document discusses the design of singly reinforced concrete beams. It covers:
1) Concrete stress distribution and equivalent stress blocks. The depth and location of the neutral axis are defined.
2) Strength analysis using equilibrium of forces and moments. Flexural strength equations are developed.
3) Determination of steel ratios including balanced, maximum, and minimum ratios based on material strengths and code requirements.
4) Procedure to determine the flexural strength of a beam given its dimensions and material properties.
5) Method to calculate the required steel area to resist a given bending moment based on an iterative approach solving for the depth of the compression block.
Women's Running Magazine Subscription UK Offeryogisri001
Trikarana Transcendental Meditation (TTM)
Yogi Sriji is an enlightened spiritual leader; founder of Trikarana Yoga Charitable Trust and Trikarana Transcendental Meditation (TTM) Center, a unit of the Trust, started in the year 2009 in Coimbatore, an Industrial City in Tamil Nadu, India.
The document outlines a lesson plan on a topic, including the learning outcome, contents to be covered such as new terms and facts, classroom interaction procedures such as asking questions, and review questions at the end to assess understanding. It provides the structure and contents of the lesson to help teach the topic. The teacher is to go through the contents, engage students through questioning techniques, and evaluate learning through the review questions.
This document discusses barriers to traditional work measurement methods for skilled labor environments and presents alternative methods that can overcome these barriers. It outlines social barriers like workers finding measurement demeaning and technical barriers like work variation. Modern methods use mobile software, work sampling, predetermined motion times systems, and training workers to measure themselves using tools like tagging sheets or swipe cards. These alternatives can provide rapid, precise estimates needed to assess process improvements for skilled custom jobs more effectively than traditional stopwatch observation.
The document is a magazine from the City of Prospect that provides information on upcoming local events, including a photo competition for dogs, plans for Tourrific Prospect which includes a ukulele challenge and the Tour Down Under bicycle race starting on Prospect Road, and articles on local businesses, recycling, gardens and the community.
Leaders inspire their teams by actively listening to employees. When managers make an effort to listen, they see benefits in engagement and positive relationships that can move an organization toward success. To create a culture where employee input is valued, senior leaders must set the tone and model active listening. The eight steps to becoming an active listener include approaching each dialogue with an open mind to learn, focusing on the speaker without distractions, asking open-ended questions, drilling down to details with specific questions, summarizing and checking for understanding, providing positive feedback, listening for total meaning including non-verbal cues, and paying attention to responses while keeping an open mind.
The document discusses giving life to something but does not provide enough context in the single sentence fragment to form a meaningful 3 sentence summary. The fragment "To give life to..." does not convey essential information about the topic, scope, or purpose of the intended document.
This document summarizes a research paper that explores the role of women and the gender gap in urban sociology through a case study of Afrikaanderwijk, a neighborhood in Rotterdam, Netherlands. The paper aims to examine the dominant Dutch integration discourse by looking at women's use of public space in the neighborhood. It discusses how urban sociology has failed to use gender as a framework and debates around public space that center on criminal youths and poor, segregated areas. The paper also provides context on migration trends in the Netherlands and debates around integration and culture.
This curriculum vitae outlines the personal and professional details of Hillina Debebe Hailu. She is currently pursuing an MSC in Software Engineering at HiLCoE School of Computer Science and Technology. Her work experience includes positions in software support, risk compliance, and programming at various banks and organizations in Ethiopia. She is proficient in languages such as Amharic, English, PHP, Java Script, and has certifications in ITIL Foundation and SWIFT system administration.
This document discusses the concepts of transference and countertransference in psychoanalysis. It notes that transference refers to how patients view their analysts based on past significant relationships, while countertransference refers to how analysts may respond to patients. The document outlines different perspectives on these concepts from Freud, Lacan, and other schools of thought. It emphasizes that transference and countertransference must be carefully handled by analysts to avoid resistance or premature termination from patients.
The document discusses the challenges posed to the right to data protection by technological developments and individuals' online behaviors. It notes that while the internet has provided opportunities to access and share information, it has also made it easy to collect and store personal data without users' full knowledge or consent. Existing data protection laws and mechanisms aim to empower individuals and provide oversight, but technological change continues to test these frameworks. Potential solutions proposed include closing the gap between individuals' desire for data control and companies' data processing practices, as well as restoring trust through strengthened legal protections and transparency. The future of data protection law will likely involve further adapting rights and regulations to new technologies and uses of personal data.
The document discusses science and technology at Yachay Technical University in Ecuador. It mentions that the knowledge gained at the university can be used to help the environment and community. It also discusses the relationship between poverty and pollution, and how developed countries control most of the world's wealth. The document proposes using new technologies to clean contaminated groundwater and soil, and applying science to improve environmental protection and responsible use of natural resources.
This document discusses the analysis and design of one-way and two-way concrete slabs. It describes how one-way slabs transfer loads in one direction while two-way slabs transfer loads in two perpendicular directions. The coefficient method is presented for analyzing bending moments in two-way slabs using moment coefficients from tables based on support conditions and span ratios. An example is provided to calculate moment coefficients and design a two-way slab using working stress and ultimate strength design methods.
This document summarizes research on using particle swarm optimization (PSO) to enhance the radiation pattern of a phase array antenna. It begins by introducing the problem of high sidelobes in phase array antenna patterns. It then provides background on phased array antennas and array pattern modeling. A 24-element linear array modeled in MATLAB is used as a case study. Standard PSO and a modified PSO algorithm are applied to optimize the current excitations and minimize the sidelobe levels. Simulation results show that both PSO approaches reduce sidelobes compared to uniform excitation, with the modified PSO performing better. Overall, the document presents research on using computational optimization methods to improve phase array antenna radiation patterns by controlling sidelobe levels
Enhancing the Radiation Pattern of Phase Array Antenna Using Particle Swarm O...IOSR Journals
The document describes a study that uses particle swarm optimization to enhance the radiation pattern of a phase array antenna by minimizing sidelobe levels. It first provides background on issues with high sidelobes in phase array antennas, such as power losses and interference. It then summarizes previous research using techniques like genetic algorithms for antenna array optimization. The study models the radiation pattern of linear arrays with different element numbers and calculates gain, finding that gain increases with more elements. However, sidelobe levels also increase relatively. Therefore, the study proposes using particle swarm optimization to optimize current excitation and control sidelobe levels while maintaining a narrow beamwidth.
This summary provides the key details about simulation results of a feedback control system to damp electron cloud instabilities in the CERN SPS:
- Simulations using the PIC code WARP modeled a bunch interacting with an electron cloud and the damping effect of a simple feedback system based on a FIR filter.
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[http://dx.doi.org/10.1063/1.4841635]
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Exponential Tapered Balun with Different Sizes for UWB Elliptical Dipole Antenna
ABF OBFN Evan Wayton nocode
1. Adaptive Beam Forming (ABF) Overlapping Beam Forming Networks (OBFN)
Author: Evan Wayton
Overview
The problem at hand is to compare the performance of a Uniformly Spaced Line Array (USLA)
implemented with non-overlapping sub array (NOSA), 2:1 overlapping sub array (2:1 OSA), and 3:1
overlappingsubarray(3:1 OSA) architectureswhenboth conventional beamforming(CBF) andadaptive
beam forming (ABF) are utilized. These three architectures are shown below in Figure 1.
Figure 1: NOSA, 2:1 OSA, and 3:1 OSA with M=24 elements
The use of sub arrays (shown as separate colors in Figure 1) reduces the number of digital receive
elements required of the array, by allowing digital receivers to be placed at the sub array level rather
than at the element level. The sub array architecture also has the benefit of being a “cookie cutter”
solution for modular arrays, which promotes an easily reproducible sub system. Other applications of
subarrays are time delaysteeringforwideband waveforms, and multiple simultaneous receive beams
[1]
Historically,overlappingsubarray architectures have helped allow beams to be scanned off broadside
withoutintroducingagratinglobe into the main lobe of the sub array pattern [2]. Though, overlapping
the sub arrays can increase the manufacturing complexity.
The overlapping sub array architecture is in no way limited to a single dimension, nor is it limited to
planarapplications. Forthe sake of time,we will introduce auniformly space linearray(USLA) underthe
three different architectures.
2. Key Results
Matlab code was generated in order to implement the non-overlapping, 2:1 and 3:1
overlapping sub array architectures. This code was then used in order to verify that as the
overlap is increased, grating lobes can be held outside of the main lobe of the sub array
pattern, even when steered off broadside.
Next, adaptive beam forming was performed on all three architectures in order to compare
performance, and relative suppression of grating lobes. It was found that for a fixed number of
elements per sub array, the number of grating lobes present, and the amplitude of the grating
lobes can be reduced by using the overlapping sub array architecture. The summary of these
results is shown in Figure 2 and Figure 3 below:
Figure 2
Figure 3
0 0.5 1 1.5 2 2.5 3
-30
-28
-26
-24
-22
-20
Peak Grating Lobe Level as a function of the Overlap Factor [0 2 3]
Overlap Factor
PeakGratingLobeLevel[dB]
20 dB
0 0.5 1 1.5 2 2.5 3
0
5
10
15
Number of Grating Lobes as a function of the Overlap Factor [0 2 3]
Overlap Factor
NumberofGratingLobes
3. Analysis and Simulation
For the NOSA, the phase progressions which control the beam patterns are (as shown on slides 129 of
the notes):
Stage 2: ∑ exp (−2𝜋𝑗
𝑑
𝜆
𝐾(𝑚 − 1)(cos(Ѳ) − cos(ɸ)))𝑀
𝑚=1
Stage 1: ∑ exp (−2𝜋𝑗
𝑑
𝜆
(𝑘 − 1)(cos(Ѳ)))𝐾
𝑘=1
For the 2:1 OSA, the phase progressions which control the beam patterns are found to be:
Stage 2: ∑ exp (−2𝜋𝑗
𝑑
𝜆
(
𝐾
2
) (𝑚 − 1)(cos(Ѳ) − cos(ɸ)))𝑀
𝑚=1
Stage 1: ∑ exp (−2𝜋𝑗
𝑑
𝜆
(𝑘 − 1)(cos(Ѳ)))𝐾
𝑘=1
For the 3:1 OSA, the phase progressions which control the beam patterns are found to be:
Stage 2: ∑ exp (−2𝜋𝑗
𝑑
𝜆
(
𝐾
3
) (𝑚 − 1)(cos(Ѳ) − cos(ɸ)))𝑀
𝑚=1
Stage 1: ∑ exp (−2𝜋𝑗
𝑑
𝜆
(𝑘 − 1)(cos(Ѳ)))𝐾
𝑘=1
Analysis and Simulation: CBF
First,the beampatterns (which in this case are identical to the bearing responses) were computed for
the non-overlapping, non-weightedarray (NOSA) architecture. These results are shown in Figure 3 and
Figure 4 below:
4. Figure 3: Stage 1, Stage 2, and Composite beam patterns for CNOBF at 90° and 98°
Figure 4: Stage 1, Stage 2, and Composite beam patterns for CNOBF with Taylor weights at 90° and 98°
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB]
CNOBF: No Weights, Phi = 90 [deg]
96 Elements, 4 Elements per Sub Array, 24 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB]
CNOBF: No Weights, Phi = 98 [deg]
96 Elements, 4 Elements per Sub Array, 24 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB]
CNOBF: Taylor Weights, Phi = 90 [deg]
96 Elements, 4 Elements per Sub Array, 24 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB]
CNOBF: Taylor Weights, Phi = 98 [deg]
96 Elements, 4 Elements per Sub Array, 24 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
5. It is seen from Figure 3 that at broadside, the grating lobes are completely cancelled by the Stage 1
beampattern.As soon as Stage 2 is steered off broadside to 98°, the grating lobes no longer align with
the nulls of the Stage 1 beam pattern, and hence manifest in the composite pattern. The peak of the
grating lobes when steered to 98° is seen to be approximately 12 dB down from the main lobe.
Figure 4 showsthat the fixedTaylorweightsdonotaidinsuppressingthe grating lobes, though they do
lower the side lobe levels. It is interesting to note that the shading created by the weights on Stage 2
widened the gratinglobesseen at 0.5 and -0.5, and in doing so caused the the “splitting” of the grating
lobes as seen in the broadside plot of Figure 4.
Next, the phasingcorresponding to that of a 2:1 OBF with Taylor weights on both the Stage 1 Sub Array
and Stage 2 ArrayFactor wasimplementedin Matlab. Note that here that Taylor weights were used on
both stages, which has allowed suppression of the grating lobes when the sub array was steered to
broadside,butstill the gratinglobe appearonlyapproximately 25 dB down upon steering off broadside
to 98°. The 2:1 OBF has provided us with an improvement in peak grating lobe level from -12 dB for
NOSA, to -25 dB for 2:1 OBF, as seen in Figure 5.
Figure 5: Stage 1, Stage 2, and Composite beam patterns for 2:1 OBF with Taylor weights at 90° and 98°
The nextstepwas to investigate the impact of a 3:1 OBF architecture. It is shown in Figure 6 that when
the sub array is steered off broadside to 98°, the peak relative grating lobe level is further reduced to
that of the peak of the Taylor weighting, approximately -42 dB down (since the grating lobes have
successfully been pushed outside of the main beam).
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB]
2:1OBF- Taylor Weights, Phi = 90 [deg]
96 Elements, 8 Elements per Sub Array, 23 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB]
2:1 OBF- Taylor Weights, Phi = 98 [deg]
96 Elements, 8 Elements per Sub Array, 23 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
6. Figure 6: Stage 1, Stage 2, and Composite beam patterns for 3:1 OBF with Taylor weights at 90° and 98°
Therefore, we have shown that the overlapping sub array architecture can be used in order to reduce
gratinglobe effects.Of course,asthe beamissteeredfurtheroff broadside,the gratinglobe will appear
whenitentersthe mainlobe of Stage 1. One methodof dealingwiththiswhichthe authorwouldlike to
investigate, is the combination of a 3:1 OBF with a “split” array, much like the homework problem of
week 6. Another method which could be used in conjunction with the 3:1 OBF architecture is the
addition of an extra element in order to cancel grating lobes.
Analysis and Simulation: ABF
Nextwe will investigate the impact of the above sub array architectures in using ABF. Note that in the
above examples we have maintained a constant number of elements, only changing the number of
elements per sub array.
As derived in the lecture notes the power from a non-overlapping ABF with a sub array architecture is
found to be:
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB] 3:1 OBF- Taylor Weights, Phi = 90 [deg]
96 Elements, 12 Elements per Sub Array, 22 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
-1 -0.5 0 0.5 1
-60
-50
-40
-30
-20
-10
0
Cosine(look angle)
NormalizedPower[dB]
3:1 OBF- Taylor Weights, Phi = 98 [deg]
96 Elements, 12 Elements per Sub Array, 22 Sub Arrays
Stage 2: Array Factor
Stage 1: Sub Array
Composite
7. When the above overlapping architecture is used, it is seen that only the α(Ѳ,ɸ) term changes. In
particularthe K becomesaK/i,where i=2,and i=3 for2:1 and 3:1 overlappingarchitecturesrespectively.
This implies that for the above examples where K=4 for NOSA, K=8 for 2:1 OSA, and K=12 for 3:1 OSA,
the K/I ratios wouldbe the same forall three cases (4/1=8/2=12/3). Therefore, there is no difference in
bearingresponse forthe 3 casesabove.The bearingresponse isshownbelow, in Figure 7, for a SNR= 20
dB.
Figure 7: ABF bearing response for NOBF, 2:1 OBF, and 3:1 OBF with with K= 4, 8, and 12 respectively.
Contact moved from 90° to 98° from left to right plot.
-1 -0.5 0 0.5 1
18
20
22
24
26
28
30
32
34
36
38
Cosine(look angle)
NormalizedPower[dB]
ABF: Phi = 90 [deg]
96 Elements, 4 Elements per Sub Array, 24 Sub Arrays
SNR = 20 dB
-1 -0.5 0 0.5 1
18
20
22
24
26
28
30
32
34
36
38
Cosine(look angle)
NormalizedPower[dB]
ABF: Phi = 98 [deg]
96 Elements, 4 Elements per Sub Array, 24 Sub Arrays
SNR = 20 dB
8. Therefore,forthe interestof the projectwe willinvestigate the impactABF with overlapping sub arrays
for a fixed numberof elementsper sub array,K. For the plotsshowninFigure 8, the numberof elements
per sub array has been fixed to be K=12. The number of sub arrays, M does not impact the result,
thoughit wasvariedinorderto maintaina constantnumber of elements. The impact of Mwould more
readilybe seenif ABIwere utilizedwith the overlapping architecture, as the degrees of freedom could
be reduced by reducing the number of sub arrays.
It is seen that for a fixed number of elements per sub array, the increasing degree of overlapping sub
arrays helps in thinning the number of grating lobes present. Also, it is seen from Figure 8 that as the
SNR increases, the grating lobe effects become more pronounced.
9. Figure 8: Grating lobe “thinning” from utilization of overlapping sub array architecture
0 50 100 150
10
20
30
40
50
60
No Overlap ABF: Phi = 90 [deg]
96 Elements, 12 Elements per Sub Array, 8 Sub Arrays
Cosine(look angle)
NormalizedPower[dB]
0 dB
10 dB
20 dB
0 50 100 150
10
20
30
40
50
60
2:1 ABF: Phi = 90 [deg]
96 Elements, 12 Elements per Sub Array, 15 Sub Arrays
Cosine(look angle)
NormalizedPower[dB]
0 dB
10 dB
20 dB
0 50 100 150
10
20
30
40
50
60
3:1 ABF: Phi = 90 [deg]
96 Elements, 12 Elements per Sub Array, 22 Sub Arrays
Cosine(look angle)
NormalizedPower[dB]
0 dB
10 dB
20 dB
10. Conclusion:
Overlappingsubarray architecturesactas a methodto reduce the number of digital receivers required
on the array. Placingthe digital receiversatthe sub array level, rather than at the element level allows
for a reduction in the number of digital receivers required. This allows processing to be done at the
beam level, rather than at the element level. The overlapping architecture can add additional
complexities in manufacturing.
The degree to which adaptive processing techniques are used in any given field depends on many
factors. That being said, there are still modern radars being produced which do not, for one reason or
another, have the luxury of adaptive processing.
Overlapping sub arrays can be used in order to thin, or push out the effects of the grating lobes. The
utilizationof ABFwithan overlappingsub array architecture, along with either using extra elements or
splittingthe array(asin Homeworkassignment6) couldbe usedto furthersuppressthe presence of the
grating lobes.
This work can be extended from one dimension to any array shape, as overlapping sub arrays may be
realized in all sorts of arrays.
11. References
[1] GlennHopkins,“Subarrays”PowerPointPresentation.GeorgiaTech Research Institute. Sensors and
Electromagnetic Applications Laboratory.
[2] D.H. Sinnott,G.R.Haack, “The use of overlappedsubarraytechniquesin simultaneous receive beam
linear arrays”, AD-P003 501. Electronics Research Laboratory. Defence Science and Technology
Organisation Department of Defense.
[2] B. Mathews,J.Griesbach,A.Brown,“WIDEBANDRADAR ADAPTIVEBEAMFORMINGUSING
FREQUENCYDOMAIN DERIVATIVEBASEDUPDATING”,
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.184.8460
[4] Fante,R. L., “SystemsStudyof OverlappedSubarrayedScanningAntennas”,IEEETrans.Antennaand
PropagationAP-28:668-669.
[5] T. Barnard, “ELE791 AdaptProcessingNotesSpring2015.pdf”