bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antenna Theory
Authors: Davis William A. , Stutzman Warren L. 
Published: April 2005

Abstract
Antenna theory provides the backbone of analysis for antennas and allows the system designer to identify basic properties of antennas to complete a system design. This article provides the foundation concepts of antennas and focuses on the radiation properties and methods for characterizing antennas. Critical components include impedance, gain, beamwidth, and bandwidth as needed for communications systems. In order to predict the limits of antenna size and bandwidth, the fundamental limits of antennas are summarized. A short introduction to the concepts of ultrawideband antennas is also provided. A system designer must incorporate the parameters of the antennas developed in this work into a full analysis of a communication system to complete the design.
Ferrite Circulators
Authors: Yung E. K. N. , Wang D. X. , Chen R. S. 
Published: April 2005

AbstractThe circulator is one of the elementary building blocks in radiofrequency and microwave circuits. It is used extensively in making basic devices for communications and radar systems. The latter are often used in broadband and high‐power rating systems at microwave and millimeter‐wave frequencies. It is, however, seldom found in consumer products because some of its functions can be performed by simpler and cheaper alternatives. However, interest in circulators has been revitalized with the emergence of mobile communications in recent years. As more and more users are accustomed to the freedom provided by cellular phones, communication without the constraint of an attached wire is considered as natural as breathing air. In addressing the ever‐increasing public demands, numerous wireless systems have been launched and more are coming. The most notable ones are wireless local‐area network, wireless local subscriber loops, and other high‐bit‐rate yet low‐error‐rate systems of data transmission. For these systems, the overlooked circulator enjoys a competitive edge as most active switches could not deliver the needed power rating and bandwidth at a reasonable price, especially those in the ultra high frequency band and beyond.
Cryogenic Electronics
Authors: Jha A. R. 
Published: April 2005

Abstract
This article is devoted to cryogenic electronics. Performance capabilities of most widely used cryogenic electronic components and devices using HTS and LTS technologies are summarized with emphasis on reliability, power consumption, and weight. Performance improvements due to integration of cryogenic electronic technology in RF, microwave, and millimeter‐wave components, including RF detectors, ADCs, MESFET and HEMT amplifiers, mixers, filters, solid‐state sources, frequency multipliers, and laser diodes are identified.
Direct Satellite Television Broadcasting
Authors: Godwin John P. 
Published: April 2005

Abstract
Direct‐to‐home (DTH) satellite television broadcasting has no strict technical or legal definition. Since the late 1970s the term has been used to delineate commercial systems that deliver television directly to consumer homesusing communication satellites in geosynchronous orbit.
This article describes the broadcasting and reception systems of a typical digital DTH broadcasting system, but does not cover the substantial infrastructure necessary for customer service and billing.
Electromagnetic Wave Propagation
Authors: Teixeira Fernando L. , Moreira Fernando J. S. , Pereira‐Filho Odilon M. C. 
Published: April 2005

Abstract
This article discusses the nature of electromagnetic wave propagation. After a brief historical overview and a description of the electromagnetic spectrum, plane waves are introduced as fundamental solutions to Maxwell's equations. Basic concepts such as wavelength, Poynting vector (power flux density), and phase velocity are explained in view of such waves. The transverse nature of electromagnetic waves and its relation to polarization is also discussed. The article continues with an examination of the relation between electromagnetic waves and sources, followed by a description of spherical and cylindrical waves. Next, the nature of electromagnetic wave propagation in lossy media is considered, where concepts such as frequency dispersion and group velocity are introduced. The interaction of electromagnetic waves with obstacles is treated next by considering scattering and diffraction phenomena, and, in more detail, the reflection and transmission (refraction) of electromagnetic waves across material boundaries. This is followed by a description of guided‐wave propagation, with emphasis on TE and TE modes in waveguides, and a description of surface and leaky waves. Finally, the article concludes by drawing the distinction between coherent and incoherent waves.
Finite Element Analysis
Authors: Jin Jian-Ming , Botha Matthys M. 
Published: April 2005

Abstract
The finite‐element method is a numerical procedure for obtaining approximate solutions to boundary value problems. It is a general, preeminent approach to solving a wide variety of problems occurring in engineering practice, including those in RF and microwave engineering. It is a powerful tool in the design and characterization of RF and microwave devices. The popularity of the finite‐element method can be ascribed to its ability to model very complex geometries and to deal with a variety of media, including inhomogeneous and anisotropic cases. Moreover, the method yields a very sparse matrix that can be generated, stored and solved efficiently. This article describes the basic principle, the numerical formulation, and some applications of the finite‐element method for analysis of electromagnetic problems in RF and microwave engineering. It also briefly discusses some computational aspects and advanced topics associated with the method.
Frequency Converters and Mixers
Authors: Angelov Iltcho , Kollberg Erik L. , Zirath Herbert 
Published: April 2005

Abstract
An essential part of most microwave receivers is the frequency converter, a device that converts the frequency of an incoming signal to another frequency. The output frequency may be downconverted, upconverted, multiplied, or divided. Important and common is the mixer, which downconverts a high‐frequency input signal fs to a much lower and more manageable signal fIF, preserving information concerning the amplitude, frequency, and phase of the input signal. The devices used are nonlinear (i.e., the relationship between current and voltage is not linear). The devices may have either two terminals (diodes) or three terminals (transistors).
Geometrical Optics
Authors: Erricolo Danilo 
Published: April 2005

AbstractA tutorial overview of geometric optics is given. The article begins with a historical introduction, followed by a review of the basic principles of geometric optics, and then the following topics are discussed: (1) paraxial approximation and ray matrix optics, (2) third‐order aberrations, (3) relationships between geometric optics and antenna theory, and (4) extensions to geometric optics.
High‐Frequency Transmission Lines
Authors: Teixeira Fernando L. , Radhakrishnan Kaladhar , Chew Weng C. 
Published: April 2005

AbstractTransmission lines are used to guide electromagnetic waves from one place to another. They are used for many types of applications; the most common application in high‐frequencies is transmission of signals, either digital or analog.In this case, high‐frequency transmission lines are often designed to maximize the operable frequency bandwidth and minimize the attenuation of the signals. The former preserves the quality of the signal being transmitted, while the latter increases the maximum possible distance of transmission.Examples of high‐frequency transmission lines include coaxial cables, optical fibers, microstrip lines, and hollow waveguides. Transmission of signals is not always limited to physically long lines. Some high‐frequency transmission lines are also used for short‐distance transmission as, for example, those used to transmit signals within a computer or to feed an antenna from its source. This article discusses various types of high‐frequency transmission lines used in RF and microwave applications and the various propagation mechanisms behind their operation.
Linear Antennas
Authors: Bhattacharyya Asoke K. 
Published: April 2005

AbstractHistorically, using a piece of radiating straight wire as an aerial, or antenna, was a natural choice for wireless communications. This radiating piece of straight wire without curvature is the linear antenna. A simple example of a linear antenna is a two‐wire transmission line carrying equal currents in opposite directions and hence no resultant radiation. A two‐wire transmission line may be bent to create an efficient radiator such as a dipole. We will describe key features of linear antennas in this article.
Low‐Power Broadcasting
Authors: Morgan Chip 
Published: April 2005

Abstract
Low‐power broadcasting systems are very interesting from a technical perspective for several reasons. Although they appear to be simple to build and easy to design, they can actually be more critical than higher‐powered stations. In fact, since the signal is local and likely to receive or cause interference, design and optimization methods for low‐power systems can make the difference between a successful operation and a failure.
Method of Lines
Authors: Toscano Alessandro , Vegni Lucio 
Published: April 2005

AbstractIn this contribution we present the method of lines for the analysis of the planar passive structures and planar transmission lines that are widely used in microwave and millimeter‐wave integrated circuits.The method of partial discretization or method of lines is a well‐established technique for the analysis of different microwave structures. The method of lines is regarded as a special finite‐difference method but is more effective with respect to accuracy and computational time than is the regular finite‐difference method. It basically involves discretizing a given differential equation in one or two dimensions while using an analytical solution in the remaining direction. The method of lines has the merits of both the finite‐difference method and the analytical method; it does not yield spurious modes, nor does it have the problem of “relative convergence.”
Monopulse Tracking Systems
Authors: Perez Manuel Sierra , Menoyo Javier Gismero , Castañer Manuel Sierra , Lopez Alberto Asensio 
Published: April 2005

Abstract
Since its first conception at the end of the World War II, the monopulse principle has become the most popular way to obtain accurate information about the target angular position in radar systems. Both tracking radars and scan radars use this principle in the accurate determination of angular deviation with respect to the antenna axis [off‐boresight angle (OBA)]. Now, not only radar but also any radiocommunication systems that need to orientate a narrowbeam antenna to the transmitter use monopulse tracking systems. Satellite or deep‐space sound communications use this kind of system to secure links with very‐narrowbeam antennas. Identification friend and foe (IFF) military systems use this principle to obtain narrowbeam information links.
This article presents the main characteristics of a monopulse tracking system. First the monopulse method is compared to other angular detection tracking systems to demonstrate the advantages of the monopulse method. A brief description of the monopulse principle is given, followed by and a more extensive description of the antennas used to obtain the main diagrams and the monopulse processors employed to obtain the error signals.
Noise and Interference Modeling
Authors: Orsak Geoffrey C. 
Published: April 2005

Abstract
Noise and interference are inevitable realities of collecting data or taking measurements in the real world. In some cases, the noise level may be so insignificant as to allow the engineer to ignore its effects. However, this situation generally occurs only in very controlled circumstances, such as those in the laboratory or when signal powers are exceptionally large relative to the noise.
Modeling these effects can range from being relatively straightforward to being rather difficult if not impossible. To assist in this endeavor, it is the purpose of this article to describe various methods of characterizing noise and interference
signals and to elaborate on some of the most popular models in practice today.
Piezoelectricity
Authors: Ito Yukio , Uchino Kenji 
Published: April 2005

Abstract
Piezoelectricity is being extensively utilized in the fabrication of various devices such as transducers, actuators, surface acoustic wave devices, and frequency control. In this article we discuss the piezoelectric effect, a brief history of piezoelectricity followed by present‐day piezoelectric materials that are used, and finally various potential applications of piezoelectric materials.
Pulse‐Shaping Circuits
Authors: Myers Brent A. , Chester David B. 
Published: April 2005

Abstract
Pulse shaping is used in the implementation of digital communication systems to minimize ISI caused by nonideal channel characteristics and nonideal component implementations.
Pulseshaping is performed in the transmit and receive filters of a communication system. The most common class of filters used for pulseshaping are Nyquist filters [13]. This article gives an overview of the theoretical foundations of pulseshaping and describes some practical implementations of pulseshaping filters.
Radiation Monitoring
Authors: Lingren Clinton L. , Weis Daniel , Bleher George L. , Giegler Donald P. 
Published: April 2005

Abstract
Radiation monitoring is concerned with measuring and monitoring ionizing radiation. Little is known about the harmful effects of ionizing radiation at levels that are typically encountered in our environment (natural background levels). In today's society there are areas where the use of ionizing radiation that must be monitored according to state or federal government regulations to ensure that radiation does not pose a hazard to personnel or to the environment: areas include radiation for instructional use in schools and universities, medicine, industrial gauging, sterilization of medical supplies or food, mining and milling of radioactive ores, steel mills, space flights, fusion facilities, and nuclear reactors. Radiation monitoring in nuclear power plants is discussed in detail later in this article. Any of the facilities discussed prior that has one or more licensable radiation sources must have instruments that can measure the radiation from the source(s) and must provide personnel monitoring devices, such as film badges, ring badges, or thermoluminescent dosimeters (TLDs), to monitor the dose that personnel receive who work where they may be exposed to radiation from the source(s) that exceeds 10% of federally established limits.
Radio Broadcast Studio Equipment
Authors: Lowery Walt 
Published: April 2005

Abstract
This article attempts to describe the state of the art in equipment and standards of engineering practice. Broadcasting technology now provide a digital signal path from the audio source to the transmitter.
The broadcast engineer can now build a studio using source material from digital audio storage devices mixed on a totally digital console. The console could become a
touch‐screen controlled computer. The all‐digital processing system has arrived.
Retooling to provide the new technology in hardware challenges the equipment industry. New names are emerging and some of the industry leaders are fading from vogue as they fall behind the pace of changing technology. Pressure will be on broadcast engineers also to educate themselves in order to provide competitive product to their listeners and viewers.
Reflectometers, Time‐Domain
Authors: Rusek Andrew 
Published: April 2005

Abstract

Time-domain reflectometry
(TDR
) is one of the most useful methods of analyzing signal integrity in transmission media. This includes conventional “hardwired” devices such as cables, microstrip transmission lines, and other transmission paths found in radiofrequency, microwave, and high‐speed digital circuits and systems. This article describes the basic concepts of the TDR
technique as well as associated with a related technique:
time-domain transmission
(TDT
). Through the course of this article, conventional TDR
signal measurements related to various transmission‐line loads are demonstrated and discussed. In addition, a
differential
TDR
system is presented. Finally, TDR
/TDT
test results illustrating reflections due to parasitic effects, as well as
normalization techniques
in modern TDR
systems, are described.
Slotlines
Authors: Lee Chung-Yi , Itoh Tatsuo 
Published: April 2005

AbstractThis article introduces one type of high‐frequency transmission line called the slotline. The configuration, terminology, analysis, and applications are discussed in subsequent sections. A slotline is an uniplanar wave‐guiding structure proposed by Cohn in 1968. We will use the spectral domain approach to analyze the slotline. The propagation constant and the characteristic impedance are obtained from this rigorous analysis. Slotlines can be built using the same fabrication process for the microstrip line and the coplanar waveguide (CPW). Slotline discontinuities, coaxialto‐slotline, microstrip‐to‐slotline, and CPW‐to‐slotline transitions are investigated in this article.
Telemetry
Authors: Boyadzhyan Victor 
Published: April 2005

Abstract
The purpose of a telemetry system is to convey measurement information reliably and transparently from a remotely located data generating source to users located in space or on earth. Typically, data generators are scientific sensors, science housekeeping sensors, engineering sensors, and other subsystems on board a spacecraft. The telemetry link is the voice of the spacecraft, providing two basic types of information: performance and experimental information.
Transmission Line Theory
Authors: Settaluri Raghu K. 
Published: April 2005

Abstract
This article presents an overview of one of the important topics in RF and microwave engineering, the transmission line theory. In several ways, transmission line theory bridges the gap between electromagnetic theory and basic circuit theory. At high frequencies, when the physical lengths of transmission lines are comparable with wavelength, time‐delay effects become predominant, leading to the distributed nature of the transmission line. This article focuses on studying the phenomenon of wave propagation on transmission lines by using the cascaded equivalent lumped‐element representation and application of basic circuit theory principles. First, a quick description of several commonly used transmission line structures and a brief description about the propagating modes are presented. Transmission line equations, relating the voltage and current on a general transmission line are derived in time‐ and frequency‐domains. Next, wave propagation on infinitely long and finite length transmission lines is described. Propagation parameters, such as characteristic impedance and propagation constant, are derived in terms of transmission line parameters. Special cases of lossless, and distortionless lines are cosidered and their propagation characteristics are studied. Terminations such as open‐circuit, short‐circuit, and matched‐load are described, and the variation of input impedance, voltage, and current on the line is discussed. Next, the concept of standing wave ratio and reflection coefficient and their relationship to the input impedance is presented. Smith chart, a graphical representation to solve transmission line problems, is described along with few numerical examples. The article finally presents various network parameters of a general transmission line for application to microwave network analysis.
Transmitters for Digital Television
Authors: Weirather Robert 
Published: April 2005

Abstract
Digital television for over‐the air broadcasting requires high‐power transmitters. Transmitters with high peak power and excellent linearity are required. Combined transistors and vacuum tubes are used to amplify the coded orthogonal frequency‐division multiplex (COFDM) or eight‐level vestigial sideband quadrature amplitude modulation (8 VSB) to kilowatts of RF power.
Waveguide Components
Authors: Budimir D. 
Published: April 2005

AbstractThis article describes and illustrates the various types of waveguide components. Particular attention is paid to waveguide as transmission lines, mode transducers, terminations, attenuators, resonators, filters, diplexers, and multiplexers. Experimental results of standard waveguideE‐plane filters, and simulated results of standard and ridged waveguideE‐plane filters, diplexers, and multiplexers are presented.
Waveguides
Authors: Vorst André Vander 
Published: April 2005

AbstractIn the electromagnetic spectrum, microwaves are the waves whose wavelengths are comparable to ordinary laboratory dimensions. Furthermore, smooth surfaces of good conductors form very perfect reflectors for them. As a consequence, an electromagnetic wave in a reflecting pipe is reflected back and forth from wall to wall, so that it can travel to large distances with small attenuation. Hence we have “waveguides” as transmission lines, dealing with electromagnetic fields in the inside of hollow regions, rather than outside wires for more conventional electric applications, or waves in free space as in optics, and the propagating electromagnetic field is confined to the finite region of the guide by reflecting walls. The present article reviews the basic theory and the different geometries used in the various applications of such hollow waveguides. It also reviews specific recent (as of 2003) developments, such as theoretical advances, waveguides with arbitrary cross section, and ridged and grooved waveguides.
Wavelength Meter
Authors: Guy Martin , Latrasse Christine , Villeneuve Bernard , Têtu Michel , Tremblay Pierre 
Published: April 2005

AbstractWavelength meters are instruments designed to measure the wavelength of an electromagnetic wave. Electromagnetic waves are the classic way to represent modifications of the space surrounding a moving electrically charged body. Time‐varying electric and magnetic fields are produced and can be sensed.Wavelength is a well‐established parameter when considering a monochromatic (single‐frequency) plane wave propagating in vacuum. It is the distance between two planes, measured along the direction of propagation of energy, where the phase and its derivatives have the same values.
Wideband Amplifiers
Authors: Narayanan Mysore 
Published: April 2005

Abstract

More recent developments in broadband communications systems have forced the development of circuit components that are more suited and more appropriate for broadband applications. In addition, the development of broadband communication systems has led the way to an increasing demand for use of wideband amplifiers. It should be recognized that distributed amplifiers have been critical
building
blocks in many such systems because of their performance characteristics, which are clearly
wideband
.
Yagi–Uda Antenna
Authors: Kaneda Noriaki , Deal W. R. 
Published: April 2005

Abstract
The Yagi–Uda antenna is one of the most practical and commonly used antennas. It features high gain and low weight and profile, and is inexpensive to manufacture. In this article, the fundamental operation of the Yagi–Uda is discussed, as well as a classic graphical technique for obtaining a fixed gain design. Several modern versions of the Yagi–Uda antenna are also described that permit operation of the antenna at microwave frequencies and allow for simple integration into planar arrays.