This document discusses practical considerations for near-field antenna measurements. It covers topics like alignment of the antenna under test and probe, scan size and spacing, probe correction, scattering and reflections in indoor environments, and error budgets. It provides examples of near-field and far-field antenna pattern measurements. Near-field ranges offer advantages over far-field ranges like a controlled indoor environment and the ability to detect surface anomalies, but require transforming near-field data to the far-field domain using techniques like Fourier transforms.
This document discusses the evolution and components of phased array radar technology. It begins by describing conventional radar systems and then introduces passive and active phased array radars, which use phase shifters and attenuators instead of mechanical movement to steer radar beams electronically. Key components of phased array radars include transmit/receive modules, digital beamforming, and GaN devices. The document outlines applications for weather surveillance and discusses multi-function phased array radars.
This presentation covers:
Different types of antennas used in satellite communication
Role of an antenna
Antenna temperature
Cassegrain feed Antenna
Parabolic antenna
An active phased array radar system uses a digital beamforming architecture with transmit/receive modules behind each radiating antenna element. This distributed amplifier approach improves noise figure and clutter attenuation compared to passive arrays. Digital beamforming allows formation of multiple simultaneous beams and improved dynamic range. Dual polarized arrays can operate in different modes like alternating transmit and simultaneous receive to measure linear depolarization ratios. Future trends include integrating more components into the antenna and using wideband semiconductor devices.
Radar 2009 a 13 clutter rejection doppler filteringForward2025
This document discusses Doppler filtering techniques for radar clutter rejection. It begins with an introduction to the problem of rejecting ground, sea, rain, and bird clutter for radar systems. It then covers pulse Doppler processing techniques including the use of burst waveforms and Doppler filter banks. It concludes with a discussion of implementations of Doppler filters and issues with airborne pulse Doppler radars.
An antenna array consists of multiple spatially separated antenna elements that can be combined to improve performance over a single antenna. Antenna arrays allow for high gain, steerable beams, diversity reception, interference cancellation, and direction finding. The performance of an antenna array improves as more elements are added. Additionally, increasing the element spacing provides higher directivity, but the spacing must remain below half the wavelength to avoid grating lobes. Phased arrays use differences in phase between element signals to steer the beam electronically without mechanical movement. This allows for rapid scanning compared to mechanical antennas.
Optical amplifiers amplify optical signals directly without converting them to electricity. There are three main types: erbium-doped fiber amplifiers, semiconductor optical amplifiers, and Raman amplifiers. Erbium-doped fiber amplifiers provide high gain over long distances but require large pump powers. Semiconductor optical amplifiers are compact with lower noise but have less gain. Raman amplifiers offer wide bandwidths but need very high pump powers. Optical amplifiers allow signals to travel over 100km by compensating for attenuation losses and are essential for long-distance optical communications.
In radio and electronics, an antenna (plural antennae or antennas), or aerial, is an electrical device which converts electric power into radio waves, and vice versa.[1] It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency (i.e. a high frequency alternating current (AC)) to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be amplified.
This document discusses the evolution and components of phased array radar technology. It begins by describing conventional radar systems and then introduces passive and active phased array radars, which use phase shifters and attenuators instead of mechanical movement to steer radar beams electronically. Key components of phased array radars include transmit/receive modules, digital beamforming, and GaN devices. The document outlines applications for weather surveillance and discusses multi-function phased array radars.
This presentation covers:
Different types of antennas used in satellite communication
Role of an antenna
Antenna temperature
Cassegrain feed Antenna
Parabolic antenna
An active phased array radar system uses a digital beamforming architecture with transmit/receive modules behind each radiating antenna element. This distributed amplifier approach improves noise figure and clutter attenuation compared to passive arrays. Digital beamforming allows formation of multiple simultaneous beams and improved dynamic range. Dual polarized arrays can operate in different modes like alternating transmit and simultaneous receive to measure linear depolarization ratios. Future trends include integrating more components into the antenna and using wideband semiconductor devices.
Radar 2009 a 13 clutter rejection doppler filteringForward2025
This document discusses Doppler filtering techniques for radar clutter rejection. It begins with an introduction to the problem of rejecting ground, sea, rain, and bird clutter for radar systems. It then covers pulse Doppler processing techniques including the use of burst waveforms and Doppler filter banks. It concludes with a discussion of implementations of Doppler filters and issues with airborne pulse Doppler radars.
An antenna array consists of multiple spatially separated antenna elements that can be combined to improve performance over a single antenna. Antenna arrays allow for high gain, steerable beams, diversity reception, interference cancellation, and direction finding. The performance of an antenna array improves as more elements are added. Additionally, increasing the element spacing provides higher directivity, but the spacing must remain below half the wavelength to avoid grating lobes. Phased arrays use differences in phase between element signals to steer the beam electronically without mechanical movement. This allows for rapid scanning compared to mechanical antennas.
Optical amplifiers amplify optical signals directly without converting them to electricity. There are three main types: erbium-doped fiber amplifiers, semiconductor optical amplifiers, and Raman amplifiers. Erbium-doped fiber amplifiers provide high gain over long distances but require large pump powers. Semiconductor optical amplifiers are compact with lower noise but have less gain. Raman amplifiers offer wide bandwidths but need very high pump powers. Optical amplifiers allow signals to travel over 100km by compensating for attenuation losses and are essential for long-distance optical communications.
In radio and electronics, an antenna (plural antennae or antennas), or aerial, is an electrical device which converts electric power into radio waves, and vice versa.[1] It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency (i.e. a high frequency alternating current (AC)) to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be amplified.
This document discusses continuous wave (CW) radar and frequency modulated continuous wave (FMCW) radar. It defines radar as an electromagnetic device that can detect objects hidden from view using radio waves. Radar is classified into primary types including CW and modulated radar. CW radar uses the Doppler effect to detect moving targets based on changes in transmitted frequency. However, CW radar cannot determine range. FMCW radar modulates the transmitted frequency over time and compares the received frequency to determine both range and radial velocity of targets. Key applications of radar include military surveillance, weather monitoring, air traffic control and more.
1. Power dividers are microwave components that divide input power between output ports. Common types include T-junction, Wilkinson, and multi-section broadband dividers. T-junction dividers can be lossless or lossy. Wilkinson dividers provide isolation between output ports.
2. Directional couplers are 4-port networks that divide power between through and coupled ports. They use quarter-wave length lines and even-odd mode analysis. Voltage ratios define coupling factors. Multisection designs provide broadband operation.
3. Hybrids like the quadrature and ring hybrids are 90 or 180 degree hybrids based on symmetric/asymmetric port designs and even-odd mode analysis to provide specific scattering
Phased array antennas use interference between signals from multiple radiating elements to electronically steer antenna beams without moving parts. By adjusting the relative phases of the signals, the main beam direction can be changed. This allows for rapid electronic scanning to search for and track targets. Phased arrays are used in radar systems for military aircraft and ships where they provide advantages over mechanically scanned antennas, allowing detection of stealthy targets. Common arrangements include linear arrays that scan in one plane and planar arrays that provide two-dimensional beam steering.
This document discusses various types of array antennas and the least mean square (LMS) algorithm. It describes linear, planar, cylindrical, conical, digital, multibeam, multi-faced, and adaptive array antennas. Active and passive arrays are also covered. The LMS algorithm is used for adaptive arrays to minimize interference through continuous weight adaptation using an instantaneous gradient-based approach. The algorithm recursively updates the weight vector based on the input, desired output, error, and step size to reduce mean square error.
This document discusses various types of antennas and antenna arrays. It begins by describing common antenna types including helical antennas, horn antennas, and parabolic reflector antennas. It then discusses how antenna arrays work, noting that they are composed of multiple similar radiating elements whose spacing and excitation determine the array's properties. Examples of linear and 2D arrays are provided. The document also summarizes different array configurations and beamforming techniques as well as applications such as smart antennas and adaptive arrays. Key benefits of arrays like controlling radiation patterns electronically are highlighted.
This document discusses different types of antennas, including horn antennas, slot antennas, microstrip or patch antennas, quad-helix antennas, and notch antennas. It provides details on the purpose, design, and applications of each antenna type. Horn antennas are used to direct radio waves in a beam from a waveguide and have high gain. Slot antennas consist of a metal surface with a cut-out hole or slot that radiates waves similarly to a dipole antenna. Microstrip antennas can be printed on circuit boards and are widely used in mobile devices due to their low cost. Quad-helix antennas have four connected helix antennas and transmit measurements from remote areas. Notch antennas operate based on a cut-out section similar to
This document discusses microwave communication and factors involved in microwave link design. It describes microwave communication as utilizing radio frequencies between 2-60 GHz for communication. Key factors in microwave link design include line-of-sight considerations, loss and attenuation calculations, fading predictions, and ensuring sufficient fade margin. Proper microwave link design is an iterative process that considers propagation losses, interference analysis, and ensuring quality and availability requirements are met.
This document provides an overview of radar cross section (RCS) and techniques for predicting a target's RCS through both measurement and theoretical calculation. It begins with definitions of RCS and factors affecting it. Examples of typical RCS values for different targets are given. Physical scattering mechanisms and contributors to a target's RCS are described. Both full-scale and scale model target measurement techniques are outlined. Theoretical prediction methods including geometrical optics, physical optics, and diffraction theories are introduced. Scaling laws for applying results from scale models to full-scale targets are also covered.
Radar 2009 a 17 transmitters and receiversForward2025
This document provides an overview of radar transmitter and receiver systems. It begins with an introduction and block diagram of radar transmitters and receivers. The bulk of the document then focuses on different types of high power tube amplifiers used in radar transmitters, including klystrons, traveling wave tubes, crossed field amplifiers, and magnetrons. It also briefly discusses solid state RF power amplifiers. The document concludes with an outline of topics to be covered, including receivers and waveform generators, other transmitter and receiver subsystems, and radar receiver-transmitter architectures.
Radar 2009 a 6 detection of signals in noiseForward2025
This document summarizes a lecture on radar signal detection. It discusses detecting signals in noise, the radar detection problem, basic target detection tests, and how detection performance is affected by factors like signal-to-noise ratio and number of integrated pulses. It outlines concepts like probability of detection, probability of false alarm, and the tradeoff between the two. Integration of multiple pulses can improve performance through coherent or non-coherent integration. Fluctuating targets are also addressed.
By completing this presentation will be have a clear idea about Antenna's working principles, Antenna's Types & Antenna's Parameters. At the end to this document you'll have a brief idea about Antenna's Tilt vs Distance Calculation & Cluster wise optimum Antenna Selection procedure. Impact of antenna PIM & VSWR have been described elaborately in this document as well.
This document contains 20 slides from a lecture on radar systems and the radar equation. The slides cover topics such as the basic components of a radar system, definitions of terms like radar cross section, development of the radar range equation, sources of noise, and examples of how radar performance scales with different design parameters. Key aspects of the radar equation like transmitter power, antenna size, range, losses, and noise temperature are discussed across the slides.
The document discusses concepts of antenna arrays and their applications. It provides an overview of antenna arrays, including their need, types, parameters that influence their radiation patterns, and applications. The key points are:
1) An antenna array consists of multiple antenna elements arranged to form a single antenna with controllable radiation patterns. This allows for increased directivity, narrower beams, and electronic beam steering.
2) Common array types include linear, circular, and planar arrays. Parameters like element spacing, excitation amplitudes and phases shape the overall radiation pattern.
3) Applications of antenna arrays include radar systems, wireless communications, and radio astronomy due to their ability to focus signals in desired directions without mechanical movement.
Radio waves can propagate between two points through four main ways: directly, following the curvature of the Earth, becoming trapped in the atmosphere, or refracting off the ionosphere. Propagation modes include ground-wave, sky-wave, and space-wave propagation. Mobile radio propagation is influenced by factors like reflections, scattering, diffraction, and the electromagnetic properties of materials. Proper propagation modeling is important for wireless system design and performance.
hello readers i give my PPT presentation for about antenna and ther properties and working explain in this ppt
i hope you like it THANK YOU.......!!!!!!!
This document discusses 5G antenna technology for user devices. It provides an overview of cellular communication evolution, mobile phone evolution, and mobile antenna evolution. It then discusses 5G introductions, applications, frequency coverage, antenna requirements, and MIMO and massive MIMO technologies as they relate to 5G. Key points covered include the need for antennas to cover low to high frequency bands for 5G, isolation and interference challenges for multi-antenna designs, and using massive MIMO arrays and beamforming to improve throughput.
This document discusses the fundamentals of microwave link design. It covers topics such as the frequency ranges used, types of microwave links based on distance (long haul, medium haul, short haul), components of a microwave link including indoor and outdoor units, antennas, and factors that affect microwave link performance such as multipath fading and rain attenuation. It also provides information on polarization, diversity techniques, link budget calculations, and considerations for deploying microwave links.
The document discusses digital signal processing techniques for moving target indication radar. It describes how digital signal processing allows for greater flexibility in filter design compared to analog filters, including the ability to easily implement multiple pulse repetition frequencies. It provides an example of an airport surveillance radar system that uses a 3 pulse canceller, 8 pulse Doppler filter bank, and dual PRFs to detect targets while eliminating clutter.
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 talk will give an overview of the current phased array radar systems and its requirements for weather observations, performance in sensitivity, antenna design requirement for dual-polarized weather radars.
This document discusses continuous wave (CW) radar and frequency modulated continuous wave (FMCW) radar. It defines radar as an electromagnetic device that can detect objects hidden from view using radio waves. Radar is classified into primary types including CW and modulated radar. CW radar uses the Doppler effect to detect moving targets based on changes in transmitted frequency. However, CW radar cannot determine range. FMCW radar modulates the transmitted frequency over time and compares the received frequency to determine both range and radial velocity of targets. Key applications of radar include military surveillance, weather monitoring, air traffic control and more.
1. Power dividers are microwave components that divide input power between output ports. Common types include T-junction, Wilkinson, and multi-section broadband dividers. T-junction dividers can be lossless or lossy. Wilkinson dividers provide isolation between output ports.
2. Directional couplers are 4-port networks that divide power between through and coupled ports. They use quarter-wave length lines and even-odd mode analysis. Voltage ratios define coupling factors. Multisection designs provide broadband operation.
3. Hybrids like the quadrature and ring hybrids are 90 or 180 degree hybrids based on symmetric/asymmetric port designs and even-odd mode analysis to provide specific scattering
Phased array antennas use interference between signals from multiple radiating elements to electronically steer antenna beams without moving parts. By adjusting the relative phases of the signals, the main beam direction can be changed. This allows for rapid electronic scanning to search for and track targets. Phased arrays are used in radar systems for military aircraft and ships where they provide advantages over mechanically scanned antennas, allowing detection of stealthy targets. Common arrangements include linear arrays that scan in one plane and planar arrays that provide two-dimensional beam steering.
This document discusses various types of array antennas and the least mean square (LMS) algorithm. It describes linear, planar, cylindrical, conical, digital, multibeam, multi-faced, and adaptive array antennas. Active and passive arrays are also covered. The LMS algorithm is used for adaptive arrays to minimize interference through continuous weight adaptation using an instantaneous gradient-based approach. The algorithm recursively updates the weight vector based on the input, desired output, error, and step size to reduce mean square error.
This document discusses various types of antennas and antenna arrays. It begins by describing common antenna types including helical antennas, horn antennas, and parabolic reflector antennas. It then discusses how antenna arrays work, noting that they are composed of multiple similar radiating elements whose spacing and excitation determine the array's properties. Examples of linear and 2D arrays are provided. The document also summarizes different array configurations and beamforming techniques as well as applications such as smart antennas and adaptive arrays. Key benefits of arrays like controlling radiation patterns electronically are highlighted.
This document discusses different types of antennas, including horn antennas, slot antennas, microstrip or patch antennas, quad-helix antennas, and notch antennas. It provides details on the purpose, design, and applications of each antenna type. Horn antennas are used to direct radio waves in a beam from a waveguide and have high gain. Slot antennas consist of a metal surface with a cut-out hole or slot that radiates waves similarly to a dipole antenna. Microstrip antennas can be printed on circuit boards and are widely used in mobile devices due to their low cost. Quad-helix antennas have four connected helix antennas and transmit measurements from remote areas. Notch antennas operate based on a cut-out section similar to
This document discusses microwave communication and factors involved in microwave link design. It describes microwave communication as utilizing radio frequencies between 2-60 GHz for communication. Key factors in microwave link design include line-of-sight considerations, loss and attenuation calculations, fading predictions, and ensuring sufficient fade margin. Proper microwave link design is an iterative process that considers propagation losses, interference analysis, and ensuring quality and availability requirements are met.
This document provides an overview of radar cross section (RCS) and techniques for predicting a target's RCS through both measurement and theoretical calculation. It begins with definitions of RCS and factors affecting it. Examples of typical RCS values for different targets are given. Physical scattering mechanisms and contributors to a target's RCS are described. Both full-scale and scale model target measurement techniques are outlined. Theoretical prediction methods including geometrical optics, physical optics, and diffraction theories are introduced. Scaling laws for applying results from scale models to full-scale targets are also covered.
Radar 2009 a 17 transmitters and receiversForward2025
This document provides an overview of radar transmitter and receiver systems. It begins with an introduction and block diagram of radar transmitters and receivers. The bulk of the document then focuses on different types of high power tube amplifiers used in radar transmitters, including klystrons, traveling wave tubes, crossed field amplifiers, and magnetrons. It also briefly discusses solid state RF power amplifiers. The document concludes with an outline of topics to be covered, including receivers and waveform generators, other transmitter and receiver subsystems, and radar receiver-transmitter architectures.
Radar 2009 a 6 detection of signals in noiseForward2025
This document summarizes a lecture on radar signal detection. It discusses detecting signals in noise, the radar detection problem, basic target detection tests, and how detection performance is affected by factors like signal-to-noise ratio and number of integrated pulses. It outlines concepts like probability of detection, probability of false alarm, and the tradeoff between the two. Integration of multiple pulses can improve performance through coherent or non-coherent integration. Fluctuating targets are also addressed.
By completing this presentation will be have a clear idea about Antenna's working principles, Antenna's Types & Antenna's Parameters. At the end to this document you'll have a brief idea about Antenna's Tilt vs Distance Calculation & Cluster wise optimum Antenna Selection procedure. Impact of antenna PIM & VSWR have been described elaborately in this document as well.
This document contains 20 slides from a lecture on radar systems and the radar equation. The slides cover topics such as the basic components of a radar system, definitions of terms like radar cross section, development of the radar range equation, sources of noise, and examples of how radar performance scales with different design parameters. Key aspects of the radar equation like transmitter power, antenna size, range, losses, and noise temperature are discussed across the slides.
The document discusses concepts of antenna arrays and their applications. It provides an overview of antenna arrays, including their need, types, parameters that influence their radiation patterns, and applications. The key points are:
1) An antenna array consists of multiple antenna elements arranged to form a single antenna with controllable radiation patterns. This allows for increased directivity, narrower beams, and electronic beam steering.
2) Common array types include linear, circular, and planar arrays. Parameters like element spacing, excitation amplitudes and phases shape the overall radiation pattern.
3) Applications of antenna arrays include radar systems, wireless communications, and radio astronomy due to their ability to focus signals in desired directions without mechanical movement.
Radio waves can propagate between two points through four main ways: directly, following the curvature of the Earth, becoming trapped in the atmosphere, or refracting off the ionosphere. Propagation modes include ground-wave, sky-wave, and space-wave propagation. Mobile radio propagation is influenced by factors like reflections, scattering, diffraction, and the electromagnetic properties of materials. Proper propagation modeling is important for wireless system design and performance.
hello readers i give my PPT presentation for about antenna and ther properties and working explain in this ppt
i hope you like it THANK YOU.......!!!!!!!
This document discusses 5G antenna technology for user devices. It provides an overview of cellular communication evolution, mobile phone evolution, and mobile antenna evolution. It then discusses 5G introductions, applications, frequency coverage, antenna requirements, and MIMO and massive MIMO technologies as they relate to 5G. Key points covered include the need for antennas to cover low to high frequency bands for 5G, isolation and interference challenges for multi-antenna designs, and using massive MIMO arrays and beamforming to improve throughput.
This document discusses the fundamentals of microwave link design. It covers topics such as the frequency ranges used, types of microwave links based on distance (long haul, medium haul, short haul), components of a microwave link including indoor and outdoor units, antennas, and factors that affect microwave link performance such as multipath fading and rain attenuation. It also provides information on polarization, diversity techniques, link budget calculations, and considerations for deploying microwave links.
The document discusses digital signal processing techniques for moving target indication radar. It describes how digital signal processing allows for greater flexibility in filter design compared to analog filters, including the ability to easily implement multiple pulse repetition frequencies. It provides an example of an airport surveillance radar system that uses a 3 pulse canceller, 8 pulse Doppler filter bank, and dual PRFs to detect targets while eliminating clutter.
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 talk will give an overview of the current phased array radar systems and its requirements for weather observations, performance in sensitivity, antenna design requirement for dual-polarized weather radars.
This document provides an overview of ICT for education, including:
- The potential benefits of ICT including expanded access, increased efficiency, enhanced learning and teaching, skill formation, and improved management.
- Key prerequisites for effective ICT implementation in education such as educational policy, infrastructure, content, personnel training, and financial resources.
- Different levels of ICT use in education from passive to active based on the learning objective and role of the learner.
The West Coast of Washington and the NE and SW corners of Wyoming are regions of the contiguous United States where NEXRAD coverage is incomplete. One approach to addressing these gaps is to install additional NEXRAD-class radars. Another potential approach is to install small radar networks of the type being investigated in the CASA project. This paper compares these two approaches. We provide a meteorological and user-need assessment of present radar coverage in these regions (based on a recent feasibility study led by J. Brotzge [1]) as well as an objective assessment of the radar-coverage that would be achieved using the large radar and small radar approaches.
Dokumen tersebut membahas mengenai penerapan transistor dalam berbagai aplikasi elektronika seperti sebagai penguat, osilator, sensor, dan transduser. Transistor dapat berfungsi sebagai penguat sinyal dengan memperkuat arus atau tegangan input menjadi keluaran yang lebih besar. Transistor juga digunakan sebagai komponen utama dalam osilator untuk menghasilkan gelombang sinusoidal. Selain itu, transistor dapat berfungsi se
Dokumen tersebut membahas tentang zat padat dan semikonduktor. Zat padat dibedakan menjadi kristal dan amorf, serta jenis ikatannya seperti ikatan ionik, kovalen dan logam. Semikonduktor dibahas pada tingkat energi elektronnya, serta transportasi muatan oleh elektron dan lubang pada semikonduktor intrinsik dan ekstrinsik."
The document discusses antenna measurements and the equipment and facilities required to perform them. Key points:
- Antenna measurements are needed to characterize parameters like radiation pattern, gain, impedance, bandwidth, and polarization.
- Required equipment includes a source antenna, transmitter, receiver, and positioning system to rotate the antenna under test.
- Facilities for measurements include anechoic chambers (indoor, uses absorbing material), elevated ranges (outdoor, antennas elevated above ground), and compact ranges (uses a reflector to collimate the source antenna's spherical waves into a planar wave).
Dokumen tersebut membahas tentang rangkaian transistor pada frekuensi rendah, termasuk teorema Thevenin dan Norton untuk menyederhanakan jaringan listrik, emitter follower dan aplikasinya, serta perbandingan konfigurasi amplifier common-base, common-emitter, dan common-collector beserta faktor penguatannya.
Dokumen ini memberikan penjelasan tentang antena UHF yang digunakan untuk penerimaan siaran televisi. Antena UHF adalah antena yang digunakan untuk menerima gelombang elektromagnetik pada frekuensi 300 MHz hingga 3 GHz. Dokumen ini menjelaskan sejarah, pengertian, aplikasi, karakteristik, rumus daya pancar, keuntungan dan kerugian, pola radiasi, dan cara pembuatan antena UHF jenis yagi.
Transistor adalah komponen semikonduktor yang berfungsi sebagai penguat, saklar, dan komponen penting dalam elektronika modern. Terdiri dari tiga terminal yaitu basis, emitor, dan kolektor. Jenis transistor meliputi BJT dan FET. Transistor dapat berfungsi sebagai osilator, penguat, sensor, dan saklar dalam berbagai aplikasi seperti logika digital dan pengendali LED.
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.
This document discusses attenuators and phase shifters. It describes how attenuators are used to reduce signal power without distortion, and includes fixed and variable types. Fixed attenuators are commonly used where a fixed amount of power is needed, while variable attenuators provide continuous or stepwise adjustable attenuation using methods like flap or vane designs. Phase shifters are also discussed, including ferrite and semiconductor types. Applications of phase shifters include communication systems, radar, and industrial uses. Key specifications for digital phase shifters are provided.
Researcher KnowHow: Getting Published with IEEELivUniLibrary
This document provides guidance on writing and publishing a quality technical paper. It discusses choosing an appropriate audience and publication outlet, structuring the paper effectively, and addressing ethical concerns. The document also covers performing a literature review, taking notes, drafting an outline, and citing references properly. Finally, it provides next steps for preparing and submitting the paper for publication.
This document is the April 1999 revised edition of the Electronic Warfare and Radar Systems Engineering Handbook published by the Naval Air Systems Command. It contains over 300 pages of information on electronic warfare topics. The handbook is approved for public release and distribution is unlimited. It includes numerous abbreviations and acronyms commonly used in electronic warfare.
This document discusses microwave propagation in ferrites and their use in microwave components. Ferrites have high resistivity and magnetic properties due to electron spin, making them suitable for microwave applications. The document focuses on isolators and circulators, which are nonreciprocal devices that use ferrite material's Faraday rotation property. Circulators allow transmission from port 1 to port 2 to port 3 etc in a circular path but not in reverse. Isolators transmit power in one direction with low loss but absorb power traveling in the opposite direction, providing isolation. Faraday-rotation isolators work by rotating the polarization of the microwave by 45 degrees using a ferrite rod, allowing transmission in one direction but absorbing waves traveling in the reverse direction.
How can variables be measured in environments that are too hot, too cold, or moving too fast for traditional circuit-based sensors? A new technology for obtaining multiple, real-time measurements under extreme environmental conditions is being developed under Phase 1 and 2 funding contracts from NASA's Kennedy Space Center’s Small Business Technology Transfer (STTR) program. Opportunities for early deployment licensing and Phase 3 STTR contracts are now being accepted.
Passive, remote measuring systems can be created using new Orthogonal Frequency Code (OFC) multiplexing techniques and specially developed, next-generation SAW sensors. As a result, very cost-effective applications such as spaceflight sensing (for instance, temperature, pressure, or acceleration monitoring), remote cryogenic fluid level sensing, or an almost limitless number of other rigorous monitoring applications are possible.
Smart mm-Wave Beam Steering Algorithm for Fast Link Re-Establishment under No...Avishek Patra
Millimeter-wave (mm-wave) wireless local area networks (WLANs) are expected to provide multi-Gbps connectivity by exploiting a large amount of unoccupied spectrum in e.g. the unlicensed 60 GHz band. However, to overcome the high path loss inherent at these high frequencies, mm-wave networks must employ highly directional beamforming antennas, which make link establishment and maintenance much more challenging than in traditional omnidirectional networks. In particular, maintaining connectivity under node mobility necessitates frequent re-steering of the transmit and receive antenna beams to re-establish a directional mm-wave link. A simple exhaustive sequential scanning to search for new feasible antenna sector pairs may introduce excessive delay, potentially disrupting communication and lowering the QoS. In this paper, we propose a smart beam steering algorithm for fast 60 GHz link re-establishment under node mobility, which uses knowledge of previously feasible sector pairs to narrow the sector search space, thereby reducing the associated latency overhead. We evaluate the performance of our algorithm in several representative indoor scenarios, based on detailed simulations of signal propagation in a 60 GHz WLAN in WinProp with realistic building materials. We study the effect of indoor layout, antenna sector beamwidth, node mobility pattern, and device orientation awareness. Our results show that the smart beam steering algorithm achieves a 7-fold reduction of the sector search space on average, which directly translates into lower 60 GHz link re-establishment latency. Our results also show that our fast search algorithm selects the near-optimal antenna sector pair for link re-establishment.
This document discusses simulations of LTE macro and small cell networks operating in the 3.5 GHz band alongside radar systems. It outlines the radar and LTE network parameters used in the simulations. The simulations examine the impact of radar pulses on LTE signal quality and evaluate exclusion zones between radars and LTE systems. The results indicate that exclusion zones in previous studies may have been overly conservative and that spectrum sharing methods could allow for smaller exclusion zones between radars and LTE networks.
VLSI Architecture for Cyclostationary Feature Detection Based Spectrum Sensin...IRJET Journal
This document proposes a VLSI architecture for cyclostationary feature detection for spectrum sensing in cognitive radio networks. It aims to transform the cyclostationary detection algorithm into an application-specific integrated circuit (ASIC) design. The key aspects covered include:
1. System level design of the cyclostationary detection algorithm and architectures for internal blocks like autocorrelation, FFT, MAC, frequency selection and test statistics computation.
2. Performance analysis of the detector in additive white Gaussian noise, achieving 0.95 probability of detection at -6dB SNR.
3. FPGA implementation and verification against simulation, with 0.07 absolute error.
4. ASIC synthesis in 90nm CMOS technology, occupying 23
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
The document describes the design of a compact printed antenna for UMTS and WiMAX applications. A rectangular microstrip patch antenna with two L-shaped slits is proposed to reduce the size by 73% compared to a conventional patch antenna. Simulation results show the antenna operates in three frequency bands with return losses of -16.37 dB at 2.03 GHz, -14.56 dB at 2.65 GHz, and -21.06 dB at 3.42 GHz and corresponding bandwidths of 15.02 MHz, 12.72 MHz, and 42.36 MHz respectively. Measured results agree reasonably well with simulations. The antenna achieves multiband operation and size reduction for wireless communication applications.
This document discusses signal processing techniques for removing distortion in ultra-wideband radar and enabling network aided positioning. It describes how the synchronous impulse reconstruction technique is used to digitize wideband radar signals with relatively slow ADCs. However, when the radar is moving, phase and amplitude distortions are introduced in the reconstructed signal. The document then presents a signal processing method to compensate for this motion-induced distortion using the radar's speed and location data. It also discusses how network aided positioning systems can estimate the location of an object using signal strength characteristics and pattern matching techniques.
MO3.L09.2 - BISTATIC SAR BASED ON TERRASAR-X AND GROUND BASED RECEIVERSgrssieee
1) The document describes a bistatic synthetic aperture radar (SAR) system using TerraSAR-X satellites and a ground-based receiver called SABRINA-X.
2) SABRINA-X was designed as a low-cost, multi-channel receiver to receive signals scattered from the illuminated area as well as direct signals from the satellite.
3) Initial results using SABRINA-X to receive signals from TerraSAR-X demonstrated the ability to generate bistatic SAR images and interferograms of the Barcelona harbor area. Accurate calibration of receiver channels was important for good results.
ZVxPlus Product Brochure: Nonlinear Starter Kit For R&S VNANMDG NV
The document describes the NM310S Nonlinear Starter Kit for characterizing the nonlinear behavior of RF components using a vector network analyzer (VNA). The starter kit includes hardware and software to measure the fundamental and harmonic frequencies of devices under test up to 3 GHz. It allows users to gain experience with large-signal network analyzer techniques through visualizing spectral data, impedances on Smith charts, and time-domain waveforms. The kit is a cost-effective first step for engineers to explore nonlinear RF measurement capabilities.
NM310S Product Brochure: Nonlinear Starter Kit For R&S VNANMDG NV
The document describes the NM310S Nonlinear Starter Kit which allows users to perform introductory nonlinear measurements using their vector network analyzer (VNA). The kit includes a comb generator and software to measure the fundamental and harmonic response of devices up to 3 GHz. It allows visualization of time domain waveforms, spectral data, and derived metrics like gain to characterize the nonlinear behavior of diodes, transistors, and other RF components under real operating conditions with minimal additional equipment. The starter kit is designed to provide a low-cost entry point for engineers to gain experience with nonlinear measurement techniques.
PNAPlus Product Brochure: Nonlinear Starter Kit For Agilent VNANMDG NV
The NM310S Nonlinear Starter Kit allows users to make their first steps in nonlinear measurement techniques using their Agilent vector network analyzer. The kit includes hardware and software to measure the fundamental and harmonic frequencies of devices under test up to 3 GHz. It provides new insights into how diodes, transistors, and other devices behave under nonlinear RF conditions. The included ICE software guides users through system configuration, calibration, and nonlinear measurements in both frequency and time domains.
NM310S Product Brochure: Nonlinear Starter Kit For Agilent VNANMDG NV
The document describes the NM310S Nonlinear Starter Kit for extending a vector network analyzer's capabilities to characterize nonlinear components. The starter kit includes hardware and software to measure fundamental and harmonic frequencies up to 3 GHz of devices under test. It allows visualization of measurements in frequency domain plots, Smith charts, time domain waveforms, and 3D trajectories. The software provides easy setup and calibration for nonlinear measurements.
Dynamic sub arrays for Hybrid Precoding in Wide Band Millimeter Wave Wireless...Abdul Qudoos
This document proposes a dynamic subarray structure for hybrid precoding in wideband millimeter wave MIMO-OFDM systems. It develops an algorithm to assign transmit antennas to subsets ("subarrays") connected to each RF chain in order to maximize the sum of the largest singular values of the subchannel matrices. The algorithm sorts channel coefficients and iteratively evaluates antenna reassignments to improve the metric. Simulations show the proposed approach outperforms fixed subarray structures and performs close to fully digital precoding under certain channel conditions. The performance gains increase with larger antenna arrays and are impacted by channel angular spreads.
The document discusses simulation and testing of antennas for 4G LTE-MIMO systems. It describes simulating a PIFA antenna in CST Studio Suite to compare matched and unmatched cases. Results showed improved return loss and far-field patterns when the antenna was matched. Testing of a MIMO antenna system involved measuring isolation between antennas and comparing performance with the enclosure open versus closed.
W-BAND RADIOMETER SYSTEM WITH SWITCHING FRONT-END FOR MULTI-LOAD CALIBRATION.pdfgrssieee
The document describes a W-band radiometer system with a switching front-end for multi-load calibration. It includes a single-pole-five-throw switch that allows for fast switching between multiple reference loads for internal calibration. Modules use metamorphic high-electron-mobility transistor technology and achieve gains over 20 dB up to 105 GHz with noise figures of 2 dB. The system provides a compact alternative to external hot-cold calibration with moving parts. It will allow for integrated active loads and faster calibration times.
Predictive And Experimental Hardware Robustness Evaluation Hp Seminar 1997Piero Belforte
1) The document discusses requirements for evaluating the global robustness of digital apparatus through both predictive simulation and experimental testing.
2) It describes the need for accurate models, powerful simulation tools, and experimental validation to reliably predict issues like signal integrity, electromagnetic interference, and susceptibility to faults and noise.
3) The THRIS environment aims to meet these requirements through a standardized hardware and software testing platform that integrates commercial simulation tools with customized interfaces, enabling both predictive analysis and experimental validation of robustness for digital designs.
A Universal Printed Antenna for UHF RFID Applicationsijtsrd
In this paper, a printed rectangular monopole antenna is designed for RFID (Radio Frequency Identification) reader applications. The antenna is designed to operate at a frequency of 860 MHz to 960 MHz allocated for UHF RFID universal (worldwide) band. The antenna simulation is analyzed using 3D EM simulator, FEKO Software. The result of the antenna parameters such as radiation pattern, reflection coefficient and gain are also discussed. The proposed antenna is simple in design and fair in size. Thein Kyithar"A Universal Printed Antenna for UHF RFID Applications" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18219.pdf http://www.ijtsrd.com/engineering/electronics-and-communication-engineering/18219/a-universal-printed-antenna-for-uhf-rfid-applications/thein-kyithar
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PHYSICAL LAYER for DIGITAL TELEVISION ATSC 3.0 STANDARD based on SC – FDMA .Roman M. Vitenberg
Described a proposition for Physical Layer of Next generation broadcast television (NGBT) and ATSC 3.0 Television standard. The Proposed system is back compatible with existing ATSC standards A/53, A/153 and based on improved version of SC-FDMA modulation.
Improved Snr Of Mst Radar Signals By Kaiser-Hamming And Cosh-Hamming Window F...IJERA Editor
In this paper the effect of window shape parameter „α‟ in Kaiser-Hamming and Cosh-Hamming window functions on the signal to noise ratio (SNR) values of the Indian Mesosphere-Stratosphere-Troposphere (MST) radar is computed. The six parts of multibeam observations of the lower atmosphere made by the MST radar are utilized for the analysis of results. Prior to the Fourier transformation, the in-phase and quadrature components of radar echo samples are weighted with proposed windows based on the Kaiser-Hamming and Cosh-Hamming Window functions. The effects of data weighting with the change of the window shape parameter „α‟ of the Kaiser-Hamming and Cosh-Hamming Window functions are given in it. It is noted that the increase of variable window shape parameter „α‟ increases the signal to noise ratio values and a better improvement is reported. For Kaiser-Hamming and Cosh-Hamming Window functions are proposed to analyze the MST radar return signals to obtain optimum values of the window shape parameter. The results shows the improvement of signal to noise ratio of noisy data due to the effect of side lobe reduction and demands for the design of the optimal window functions.
This document presents the design of a 4th order continuous-time bandpass sigma-delta modulator operating at 280 MHz for digitizing narrowband signals at 70 MHz. A novel transconductance amplifier was developed with high linearity at high frequencies. Simulation results show the modulator achieves a signal-to-noise ratio of 55 dB over a 5 MHz bandwidth while consuming 25 mW of power. The modulator uses a Gm-C loop filter and was implemented in a 0.18 μm CMOS process.
Why Use SAW Sensors and Tags?
- Frequency/time are measured with greatest accuracy compared to any other physical measurement (10-10 - 10-14).
- External stimuli affects device parameters (frequency, phase, amplitude, delay)
- Operate from cryogenic to >1000oC
- Ability to both measure a stimuli and to wirelessly, passively transmit information
- Frequency range ~10 MHz – 3 GHz
- Monolithic structure fabricated with current IC photolithography techniques, small, rugged
Similar to Phased Array Antenna Measurement in Near Field Range, Jorge Salazar (20)
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
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Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
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Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Phased Array Antenna Measurement in Near Field Range, Jorge Salazar
1. Practical considerations for a Near-Field
antenna measurements
MICROWAVE REMOTE SENSING LABORATORY SEMINAR
UNIVERSITY OF MASSACHUSETTS, AMHERST
Presented by:
Jorge Luis Salazar-Cerreño
R
jlscerreno@gmail.com
casa Engineering Research Center for
Collaborative Adaptive Sensing
of the Atmosphere
March 28th, 2011
2. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Outline
• Introduction of antenna pattern measurement I
• Practical considerations for Near-Field antenna measurement
– Alignment of AUT and probe
– Span size and sampling spacing
– Probe correction
– Scattering multireflection in the room
– Leakage
– Error budget
• CASA Phase-tilt antenna patterns
• Recommendations for antenna test plan
3. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Outdoor antenna measurements
• Outdoor Antenna Test Range
(OATR) is used for moderate FF
distances.
• One critical factor in outdoor
range systems is to find a place
free of clutter and free of RF
interferences.
• Another critical factor is
environmental changes (rain,
humidity, temperature, etc) that
can delay the test.
• The scanners required are
inexpensive in comparison with
dB Systems Inc.
the indoor range systems. The 2005 So. Turf Sod Rd. Hurricane, Utah 84737 U.S.A.
equipment cost of the scanners
can be lower than $40K.
4. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Example of FF antenna measurement 0
-5
-10
-15
pattern (dB)
-20
-25
-30
Simulated
FF-Measured
-35
-40
-40 -35 -30 -25
theta(deg)
X-Band Frequency
Scan Array Antenna
64x64 Microstrip Patch
Antenna Elements
Eric Knap and Jorge Salazar
5. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Indoor FF measurements
Advantages
– Provide a controlled environment and
an all-weather capability. Can eliminate
delays due to weather (rain, humidity,
temperature changes, etc)
– The measuring system is time and cost
effective. It requires only a small area.
– Patterns are as accurate as those
measured in a FF range
– Can provide a full characterization of
the antenna patterns.
– Compatibility with security
requirements
Disadvantages:
– FF distances FF=2D2/ Lambda
– Cost is driven by the absorbers and
scanner .
pag#&#
6. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Limitations of indoor FF measurements
2
2L
d FF
7. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Measured Elevation Patterns in Indoor Far field range
Example of the limitations FF INDOOR
1rst SLL higher in
of indoor FF measurements 2-3 dB than
expected
Measured Elevation Patterns in Planar Near Field range
PLANA NF
• X- Band CASA array antenna
• AUT size: 0.5mx0.25m
• Frequency: 9.36 GHz
• Far-field distance :16m
• Length of range:7m
8. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
FF distance limitations in FF range systems
(MIRSL antennas)
S-band C-band X-Band Ku- Band Ku- Band Ka- Band W- Band
CASA
Units FM-CW IWRAP IWRAP AMFR AMFR AMFR
X-POL
Frequency GHz 2.94 5.11 9.36 13.25 13.25 33 95
Lambda m 0.1020 0.0587 0.0321 0.0226 0.0226 0.0091 0.0032
3dB BW deg 3.00 6.58 2.08 6.40 0.75 0.70 0.70
Aperture size m 2.21 0.58 1.00 0.23 1.80 0.91 0.35
FF Distance m 95.7 11.5 62.4 4.7 286.2 182.2 77.6
FM-CW: Frequency Modulated Boundary Layer Profiler
2 L2
2 L2 f
IWRAP: Imaging Wind and Rain Airborne Profiler
CASA/X-POL: Ip1 ,Phase-Tilt and X-POL Radar Systems d FF
AMFR: Advance Multi-Frequency Radar (AMFR) c
9. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Compact antenna test range (CATR)
• Compact Antenna Test Range (CATR)
uses a reflector, or set of reflectors,
designed to collimate the radiated
pattern and create a plane wave at
considerably shorter distances.
• CATR provides a good protection
against weather , RF interference
and security.
• CATR is costly (3X-4X FF indoor).
– Requires a heavy 3 axes positioner
– Requires larger space than FF Indoor X-band surface surveillance radar test in the compact
– Requires expensive rolled-edge reflector antenna test range at the company's facility in Hengelo,
to reduce diffraction and quiet-zone the Netherlands.
(ex. $250K for only the reflector)
10. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Near-Field (NF) range system
• NF provides the same advantages of any indoor
range system in terms of controlled environment,
real estate, interferences and accuracy.
• NF provides additional features, such as back
field projection, that are helpful to detect
anomalies in the surface of the AUT, especially in
active phased-array antennas.
• The Near-field range consists of a interferometer
connected to a field-probing antenna carrier by a
precise robotic system. The antenna probe is
moved through a planar, cylindrical or spherical
surface near the antenna under test (AUT)
• The near-field system operates by measuring the
phase front of the AUT and mathematically
transforms the phase front into the equivalent
far-field angular spectrum. For a planar near field,
the phase front and angular spectrum is related
to the Fourier Fast Transform (FFT)
pag#&#
11. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
What kind of scan surface NF use?
CASCA antenna lab has a P-C and S Near-Field system
pag#&#
12. casa Engineering Research Center for
CollaborativeAdaptive Sensing of the Atmosphere
Antenna range systems at UMASS
CASCA antennas Lab. has two range systems.
• NSI Taper FF range system
– Frequency Range : 1-40 GHz,
– Absorber size: 6”
(CF-6, 32dB@3GHz-50dB @50GHz)
– Length: 21’ (6.4m)
– 1 axes-positioner
– Base on PNA 8360 (1-40GHz)
• NSI S-C and Planar NF range
– Frequency Range : 1-40 GHz,
– Absorber size: 8” (30dB @1GHz-50dB @50GHz)
– Length: 14’x10’ (4.2mx3.0m)
– 1 axes-positioner for S and C
– Only in operates in CW mode
– Base on PNA 8360 (1-40GHz)
pag#&#
13. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Practical considerations
to perform a NF antenna measurement
• Alignment of the AUT and probe
• Span size and sampling
• Truncation effect
• Scattering and reflections
pag#&#
14. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Effects of misalignment between
probe and AUT
Beam Pointing Errors in P-NF (in deg)
• Alignment is more critical Band S-band X-Band Ka- Band
Aligment CASA , X-
in NF spherical and NF Accuracy
FM-CW
POL
AMFR
cylindrical in NF scanners Frequency GHz 2.9 9.4 33.0
Lambda m 0.10 0.03 0.01
• In NF planar scanners the 3dB BW deg 3.00 2.08 0.70
alignment depends on the Antenna size
Visual (1cm)
m
deg
2.21
0.130
1.00
1.146
0.91
6.274
AUT size and mechanical Tape measur. (5mm) deg 0.065 0.573 3.147
Laser (0.1mm) deg 0.001 0.011 0.063
stress
pag#&#
15. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Effects of misalignment between
probe and AUT (cont)
2 deg
X-band CASA Dual-Polarized
Phased Array Antenna
(By: Jorge Salazar and Rafael Medina)
pag#&#
16. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Effect of misalignment in Xpol
4 dB
PUT PICTURE OF
HORN AUT
17dB
Setup of standard Ku-band Horn antenna
Zo=4mm
ro=2deg
17. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
How to improve the alignment
• Use lasers and levels to
verify the axis
orthogonality
• Use the electrical
alignment technique
developed for S-NF by NSI
• Use the post-processing
techniques such as Motion
Tracking Interferometer
developed also by NSI
pag#&#
18. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Motion tracking interferometer
• Measures time variant
Az, El and Z motion
between the AUT and
probe, including effects
of:
– Thermal effects
– Cables
– Mechanical stress of
Note:
AUT.
Motion Tracking Interferometer is a new
• US patent #5,419,631 feature of NSI P-NF that cost $10K
pag#&#
19. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Important points about alignment
• Misalignment is more critical in Spherical than in
Cylindrical and Planar scanners.
• Misalignment in P-NF is critical for large array
antennas that operate at higher frequencies
• Misalignment is critical for low cross-polarization
measurements
• For S-and C-NF we can use the electrical alignment
and for P-NF we can use the post-processing
techniques such as Motion Tracking Interferometer
• Beside there are several techniques to align the
antenna and probe, those are expensive.
20. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Span setup and Sample Spacing
• Span size (L) is calculated as function of D,
Z, and θ. t=0.5λ sample
• Z is the distance of the probe to the AUT, spacing in
that is recommended use a value between X and Y (hight
3λ to 5λ. frequency)
• D< 3λ is not recommended because the
reflections of the probe and AUT and also
because at than be possible capture
evanesces waves that can affect the
antenna performance (ripples).
• D< 5λ, is ok but the span is larger and the Z
measurement takes so long.
• Sample spacing recommended is around
0.5 λ. Oversampling lower that S< 0.48 λ
can introduce aliasing that can be
represented as peaks in the sidelobes.
NOTE:
• CASCA NF range system scan size is 5’x5’ (1.5m x 1.5m)
21. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Truncation in P-NF
• Truncation eliminates information about the AUT
sidelobes beyond an angle determined by the
measurement geometry and filters out all
information about the evanescent modes.
• Truncation of planar near-field data is the major
source of uncertainty.
• Advantages: reduces time, reduces scattering
pag#&#
22. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Effect of the truncation
in the FF antenna patterns
With truncation at 50”
No Truncation (Span 60”)
MIRSL Ku-band Interferometer
(Courtesy Anthony Swochak)
23. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Truncation effect
in the scan
AUT patterns
No Truncation
“Bad” Truncation
24. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Truncation effect
in the scan
AUT patterns
No Truncation
“Bad” Truncation
25. Radiation of the
corporate fed
Load
resistor
MIRSL Ku-band IWRAP antenna
26. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Summary of Sampling and Truncation
• Use ~0.5λ sample spacing in X and Y (for the highest
frequency)
• Use between 3 λ to 5 λ as separation between the
probe and the AUT
• Truncation can affect the antenna patterns principally
in the far region of sidelobes. However in scanning
antenna the beam pattern can be affected significantly
• Perform first a full scan measurement and then define
the truncation area when the fields are below -40dB
using NN plots or fields projected to the surface.
pag#&#
27. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Scattering and reflections inside the
anechoic chamber
• Absorbers are not perfect, they
can provide an absorption up
to 40dB (1-40GHz)
• Sources of reflections:
– AUT and probe
– AUT and scanner/support
– AUT and walls (including floor
and ceiling)
• Taper anechoic chambers
minimize the reflection in walls
J. Appel-Hansen, “Reflectivity level of radio anechoic chambers,” IEEE
Trans. Antennas Propag., vol. AP-21, pp. 490–498, 1973.
28. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
RF Absorber and quiet zone room
GROUND OR SHIELDED ROOM 6" PYRAMIDAL RF ABSORBER WITHOUT GROUND
6" PYRAMIDAL RF ABSORBER
55
3GHz
50 6GHz
10GHz
45 18GHz
40 35dB
Reflectivity (dB)
Reflectivity (dB)
35 30dB
30
25
20
15
10
0 10 20 30 40 50 60 70 80
Theta (deg)
29. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Horizontal Setup
Effect of reflections in
2010
Azimuth patterns NO ABSOBERS
IN FLOOR
Horizontal Setup
• Ku Band Interferometer Antenna 2011
• AUT size: 45”x1.25”
• Frequency: 13.195 GHz- 13.295 GHz
Patterns obtained using Slot Array Antenna designed by Ahtony Swochak.,
“Development, implementation, and Characterization of a Ku Band
30. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Horizontal Setup
Effect of reflections when 2011
AUT is in vertical position
Vertical Setup
2011
31. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Vertical setup
Effect of reflections when
AUT is in vertical position
Horizontal setup
• X- Band CASA array antenna
Size: 22”x12”
• Frequency: 9.36 GHz
32. casa Engineering Research Center for
CollaborativeAdaptive Sensing of the Atmosphere
Techniques to estimate the reflections in anechoic
chamber in NF NSI system
a. Self comparison technique:
The multipath effect can be identified
by observing the changes in the FF-
patterns changing the NF test
parameters such as:
• AUT-to-probe separation
• AUT-to-scanner separation
• AUT-to-wall separation
• AUT orientation in Az and El
• AUT lateral movement
• This test requires the probe
translation stage in Z (~$7.5K)
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EVALUATING NEAR-FIELD RANGE MUTI-PATH., Gregory F. Masters., Nearfield Systems.,
1330 E. 223rd St. #524 Carson, CA 90745
33. casa Engineering Research Center for
CollaborativeAdaptive Sensing of the Atmosphere
Techniques to estimate the reflection
in anechoic chamber in NSI NF system
2’x2’ metal
b. MARS: Mathematical Absorber obstruction
Reflection Suppression, is a post-
procesing technique developed by AUT
NSI useful to mitigate unwanted Planar slot
reflections. waveguide probe
antenna
MARS analisis of the measured
data and a special mode filtering
process to suppress the
undesirable scattered signals.
The technique is a general
technique that can be applied to
any S –NF and C-NF range systems.
NOTE:
Add this feature to CASCA NF range system requires additional cost of $15K
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IMPROVING AND EXTENDING THE MARS TECHNIQUE TO REDUCE SCATTERING ERRORS, Greg Hindman & Allen C. Newell
Nearfield Systems Inc. 19730 Magellan Drive Torrance, CA 90502
34. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Summary of Reflections in the room
• Absorbers are not perfect, the reflectivity values
depend on the size, frequency and installation.
• Reflectivity of the absorbers are critical for lower
frequencies .
• It is important to keep in mind that the reflections of
waves on the ground, ceiling and uncover scanner
support can affect the main beam, sidelobes and
cros-pol patterns of the AUT considerably.
• Two common techniques can be used to minimize the
scattering and reflections inside the room.
– In P-NF use the Z-spacing
– In S-NF, C-NF use MARS
35. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Probes and probe correction
• Probe types: There are
several probe types that you
can use: OEWP, Dipoles, MS
Patches, Horns, Conical
antennas, etc. Dual -log periodic
antennas 3GHz-
• Probe correction: This is the The QR-1 is a broadband, dual
polarized quad-ridged horn. It
17GHz
process of removing the effect operates from 750 MHz to 6 GHz.
of the pattern probe in the
AUT pattern (Co and Xpol
components).
• Probe data are calibrated and
certified by entities such as
National Institute of Standards MS Patch antenna
& Technology (NIST)
OEWP antenna probes
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How the probe can
affect the AUT patterns
in Planar NF
AUT OEWP
REF. PROBE CORRECTION EFFECTS ON PLANAR, CYLINDRICAL AND SPHERICAL NEAR-
FIELD MEASUREMENTS GREG HINDMAN, DAVID S. FOOSHE
37. casa
How the probe can
Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
affect the AUT
patterns in
Cylindrical NF
AUT OEWP
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REF. PROBE CORRECTION EFFECTS ON PLANAR, CYLINDRICAL AND SPHERICAL NEAR-
FIELD MEASUREMENTS GREG HINDMAN, DAVID S. FOOSHE
38. casaHow the probe can
Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
affect the AUT
patterns in
Spherical NF
AUT OEWP
REF. PROBE CORRECTION EFFECTS ON PLANAR, CYLINDRICAL AND SPHERICAL NEAR-
FIELD MEASUREMENTS GREG HINDMAN, DAVID S. FOOSHE
39. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
How the probe can affect the AUT
cross-polar patterns
Θ=45 deg
Θ=45 deg
Θ=45 deg
Xpol: 23dB
Planar NF Cylindrical or Θ=0 deg
Xpol: -40dB
Spherical NF
REF. PROBE CORRECTION EFFECTS ON PLANAR, CYLINDRICAL AND SPHERICAL NEAR-
40. casa Engineering Research Center for
CollaborativeAdaptive Sensing of the Atmosphere
Leakage in room
• The main source of leakage in near-field
measurements are produced by cables,
connectors and bad connections with the
AUT and the probe.
• Leakage from cables, connectors and the
RF source can be identified and reduced
by using well shielded cables, tightening
connectors and placing instruments in
shielded enclosures.
• One way to verify the leakage between
cables, connectors and the probe or
antenna is terminate first the AUT and
measure in S-C or P NF.
41. casa Engineering Research Center for
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Error budget for -30dB SLL measurement
EVALUATING NEAR-FIELD RANGE MUTI-PATH., Gregory F. Masters., Nearfield Systems.,
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1330 E. 223rd St. #524 Carson, CA 90745
42. casa Engineering Research Center for
CollaborativeAdaptive Sensing of the Atmosphere
Antenna range systems at UMASS
CASCA antennas Lab. has two range systems.
• NSI Taper FF range system
– Frequency Range : 1-40 GHz,
– Absorber size: 6”
(CF-6, 32dB@3GHz-50dB @50GHz)
– Length: 21’ (6.4m)
– 1 axes-positioner
– Base on PNA 8360 (1-40GHz)
• NSI S-C and Planar NF range
– Frequency Range : 1-40 GHz,
– Absorber size: 8”
– (30dB @1GHz-50dB @50GHz)
– Length: 14’x10’ (4.2mx3.0m)
– 1 axes-positioner for S and C
– Only in operates in CW mode
– Base on PNA 8360 (1-40GHz)
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43. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
V-pol
44. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
V-pol
45. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
V-pol
46. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
V-pol
47. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
H and Hx at NN-FF of PTAA (64x32), θ=0º, SC
CASA Phase-tilt
antenna azimuth
Patterns
V-pol
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Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
H-pol
49. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
H-pol
50. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
H-pol
51. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
CASA Phase-tilt
antenna azimuth
Patterns
H-pol
52. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
H and Hx at NN-FF of PTAA (64x32), θ=0º, SC
CASA Phase-tilt
antenna azimuth
Patterns
H-pol
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CASA Phase-tilt antenna elevation patterns
Measured patterns of 32x1 linear array in LRU (32X18)
V-port H-Port
Parameter Value@9.36GHz Parameter Value@9.36GHz
BW 3.81 deg BW 3.62 deg
SLL1(L/R) -29/-26.5 dB SLL1(L/R) -23.2/-22.5 dB
Emax(dB) -43.83 dB Emax(dB) -43.30 dB
Xpol_brodside -34 dB (rel) Xpol_brodside -38.7 dB (rel)
ICPR2 -34.4 ICPR2 -34.0
Measured results:
• RL better than -13 dB at Resonant frequencies for H and V
Patch layer Foam layer
• Impedance bandwidth: 200 MHz at RL of -10 GHz (improved in 80 MHz)
Fed layer • Beam pattern bandwidth: 100 MHz (improved in 40 MHz)
Reflector layer • Isolation port -27 dB
54. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Recommendation for an antenna
measurement in NF system
• Never perform an antenna measurement without a reference of patterns of
the AUT (simulated, previous measurement).
• Understand first how the errors (fabrication, random errors) can affect the
antenna patterns.
• Before performing a measurement, make sure that scattering and
reflection in the room are low enough to avoid contamination of the AUT
measurements.
• Make sure that the size of the scanner is larger than the span required for
the AUT.
• Perform a stability test ( to evaluate the effect of mechanical stress and
temperature versus time).
• Perform a leakage test to be sure that cables are well connected with the
AUT and receiver.
• Keep in mind that the cross-polar measurements are very sensitive to
alignment and also reflections in the room.
• Perform an antenna test plan and discuss details with your advisor or person
who has experience doing this type of measurement.
• Call me at 413-123456 if you need some help. I will charge you a beer/hour.
55. casa Engineering Research Center for
Collaborative Adaptive Sensing of the Atmosphere
Consideration for a good Antenna Plan Test
• Have preliminary results of AUT (simulations previous meas. Paterns)
• Estimation the time for each specific test measurement
• Have in mind how the position errors can affect your measurments.
• Take in consideration the alignment of AUT and probe
• Do a stability test (mechanical stress, temperature)
• Monitoring the SNR vs Frequency (for large bandwidth antenna)
• Take in consideration the scattering issues at lower frequencies (more
if you wan very low cross-pol values ( better that 25dB)
• Take in consideration the Probe data to be used to correct the probe
effect
• Coordinate systems (Az/Ele, Theta/Phi, X /Y)
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Thanks
In this Picture Jorge Salazar and Rafael Medina taking antenna
patterns of CASA dual-polarized phased -Array antenna (Feb. 2011)
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