bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cross‐polarization characteristics of spherical annular‐ring microstrip antennas
Authors: Chen Horng‐Dean , Wong Kin‐Lu 
Published: July 2007

AbstractThe cross‐polarization characteristics of a probe‐fed spherical annularring microstrip antenna excited in the TM12 mode are investigated. The analysis is performed by using a Green's‐function formulation and a Galerkin's moment‐method calculation. Numerical results of the copolarized and cross‐polarized radiated fields for various sphere radii are calculated and presented. The cross‐polarization level for different feed locations is also discussed. A great dependence of the feed location on the cross‐polarization level is observed. © 1994 John Wiley & Sons, Inc.
Classical forces on solitons in finite and infinite nonlinear planar waveguides
Authors: Ramos J. I. , Villatoro F. R. 
Published: July 2007

AbstractConservation equations for the mass, linear momentum, and energy densities of solitons propagating in finite, infinite, and periodic nonlinear planar waveguides and governed by the nonlinear Schrödinger equation are derived. These conservation equations are used to determine classical force densities that are compared with those derived by drawing a quantum mechanics analogy between the propagation of solitons and the motion of a quantum particle in a nonlinear potential well. © 1994 John Wiley & Sons, Inc.
A new aperture‐coupled rectangular dielectric resonator antenna array
Authors: Loos G. D. , Antar Y. M. M. 
Published: July 2007

AbstractA new type of planar subarray composed of rectangular dielectric resonators fed by a microstrip‐line / aperture combination has been devised and investigated. Good performance has been achieved, including a 10‐dB impedance bandwidth of 18% and excellent radiation patterns. Results for impedance bandwidth, radiation patterns, and mutual coupling effects are presented. © 1994 John Wiley & Sons, Inc.
Complex modes and wave interaction in lossless shielded waveguiding structures
Authors: Kezai T. , Vander Vorst A. 
Published: July 2007

AbstractComplex modes, singular value decomposition, shielded microstrip, fin line.Complex waves in shielded lossless inhomogeneous waveguiding structures are investigated. A new theoretical approach for wave interaction, which may result in complex modes, is developed using the theory of coupled modes. It is shown that complex modes may exist in perturbed homogeneous waveguiding structures as a result of the coupling of a pair of degenerate or nearly degenerate modes. Coupled modes, in microstrips and fin lines, are discussed and numerical data are compared. © 1994 John Wiley & Sons, Inc.
Radiation characteristics of an aperture‐coupled hemispherical dielectric resonator antenna
Authors: Leung K. W. , Luk K. M. 
Published: July 2007

AbstractThe radiation characteristics of an aperture‐coupled hemispherical dielectric resonator (DR) antenna excited at the broadside TE111mode is investigated both theoretically and experimentally. The Green's functions of the DR antenna are presented for the evaluation of fields in the upper‐half plane, and the stationary phase technique is used for the back‐lobe radiation. The effect of the slot length on the radiation is studied, and the cross‐polarized fields of the antenna are discussed. © 1994 John Wiley & Sons, Inc.
A new design approach for monolithic transimpedance receivers based on root‐locus techniques
Authors: Cocco Valter , Marietti Piero , Trifiletti Alessandro 
Published: July 2007

AbstractIn this article we present a new design method for monolithic trans‐impedance receivers that is based on a simple model of voltage amplifier and on root‐locus evaluation of closed‐loop transimpedance transfer function. © 1994 John Wiley & Sons, Inc.
Numerical analysis of rectangular waveguide multiple‐slot narrow‐wall couplers using a 2D/FDTD algorithm
Authors: Navarro Enrique A. 
Published: July 2007

AbstractSlot narrow‐wall couplers are simple but effective directional couplers. A simple and efficient approach to analyze these devices using the FDTD algorithm is presented. The technique uses a synthetic excitation and a second‐order ABC especially designed for the frequencies contained in the incident field. The method is illustrated in the computation of coupling and isolation of a two‐slot ‐20‐dB coupler and is also applied to study a three‐slot coupler. © 1994 John Wiley & Sons, Inc.
A microwave applicator using a rectangular waveguide with two symmetrically placed double L septa for processing sheet materials
Authors: Zhang Henry Z. , Mohan Ananda S. , Beard Geoffrey E. , Belcher W. Rod 
Published: July 2007

AbstractA microwave applicator using a rectangular waveguide with two symmetrically placed double L septa is proposed for processing dielectric sheet materials. The attenuation caused by the loaded lossy dielectric sheet is obtain by the Ritz‐Galerkin method combined with perturbation theory. The results show that a microwave applicator using the proposed structure can process dielectric sheets with a higher loss factor and/or larger physical dimensions. © 1994 John Wiley & Sons, Inc.
Generalized transmission‐line model for cylindrical‐rectangular microstrip antennas
Authors: Wong Kin‐Lu , Liu Yu‐Hua , Huang Chih‐Yu 
Published: July 2007

AbstractAn analysis using a generalized transmission‐line model (GTLM)for a probe‐fed cylindrical‐rectangular microstrip antenna is presented. The equivalent circuit elements for the microstrip antenna modeled as a transmission line loaded with wall admittances are derived, and the expression for the input impedance is given. Numerical results of the input impedance are calculated and presented as a function of the cylinder radius and the substrate thickness. Excellent agreement of the GTLM solutions with the experimental results is observed. © 1994 John Wiley & Sons, Inc.
A numerical absorbing boundary condition for edge‐based finite‐element analysis
Authors: Boag Amir , Boag Alona , Mittra Raj 
Published: July 2007

AbstractThe numerical absorbing boundary condition (NABC) approach is applied to the problem of deriving the local boundary conditions that can be employed in conjunction with the edge‐based formulation of the finite‐element method (FEM) to s olue electromagnetic scattering and radiation problem. The key step in this approach is to derive linear relationships that link the values of the field along the boundary edges to those at the neighboring ones. These linear relationships are satisfied, to within a certain tolerance, by all of the outgoing wave components. They can thus be used in lieu of the FEM equations employing the usual absorbing boundary conditions for the boundary edges. The NABC approach not only provides a simple way to derive an accurate boundary condition for mesh truncation, but also presemes the banded structure of the FEM matrices. © 2994 John Wiley & Sons, Inc.
Dispersion effect of substrates on the scanning behavior of chirostrip dipole antenna
Authors: Wenyan Yin , Wei Wan , Wenbing Wang 
Published: July 2007

AbstractThe far‐field behavior of a chirostrip dipole antenna on chiroferrite substrates is shown using the generalized spectral domain—exponential matrix technique, and such substrates are made from a nonreciprocal chiral medium and ferrite material. Numerical results show that both beam scanning and pattern reshaping can be achieved by adjusting the constitutive parameters of chiroferrite, and the dispersion effects of substrates are considered in detail. © 1994 John Wiley & Sons, Inc.
Design of two‐layer wave absorbers for metallic cylinders with mirror‐symmetric cross section
Authors: Hashimoto Osamu , Setsu Takanori 
Published: July 2007

AbstractThis article discusses the method for analyzing the reflection characteristics of a metallic cylinder coated with a two‐layer wave absorber. Various design curve and numerical results of the reflection characteristics are shown for wave absorbers that are optimum for masts with elliptical cross sections. © 1994 John Wiley & Sons, Inc.
Some effects of curvature on transmission performance of finite dipole FSS
Authors: Philips B. , Parker E. A. , Langley R. J. 
Published: July 2007

AbstractFinite curved dipole frequency‐selective arrays are analyzed using an integral equation to solve for the current distribution in the array elements. This article studies the effect of finiteness and curvature on the current distribution in the dipoles and on the transmission performance of the array. Results obtained are compared with measured values. © 1994 John Wiley & Sons, Inc.
Microwave small‐signal equivalent circuit model for multielectrode lasers
Authors: Elkadi H. , Hamelin R. , Vilcot J. P. , Decoster D. 
Published: July 2007

AbstractA small‐signal equivalent circuit model of the multielectrode lasers with saturable absorbers based on a modified formulation of the rate equations is presented. The Auger recombinations are taken into consideration because they largely modify the carrier lifetime at the high carrier densities that occur in such structures. An analysis of the bistability of the power‐current characteristic is presented. The model predicts an extremely high resonance amplitude as well as a very large bandwidth up to the millimetric range, which can be very interesting for microwave optical links. The results obtained using this model are comparable to those obtained using a large‐signal equivalent circuit model implanted on SPICE, the results of which are published elsewhere. The equivalent circuit obtained is a tool suitable for the study of the behavior of the multielectrode laser within a microwave optical system. © 1994 John Wiley & Sons, Inc.
Interferometric refractive index profile measurement of an optical fiber
Authors: Das Kamal K. , Arif Muhammad , Halder A. F. M. Yusuf , Alam Mohammad S. 
Published: July 2007

AbstractWe present a simple and inexpensive interferometric technique for mapping the refractive index profile of an optical fiber. This technique also enables one ot determine whether a fiber is a step index fiber or a graded index fiber. Experimental results are presented to verify the effectiveness of the proposed technique. © 1994 John Wiley & Sons, Inc.
Dynamic simulation of doppler spectra of targets with rotating parts
Authors: Bhalla Rajan , Ling Hao , Lee Shung‐Wu , Andersh Dennis J. 
Published: July 2007

AbstractWe present the dynamic simulation results of the Doppler spectra of targets containing rotating parts based on first‐principle electromagnetics computation. Our simulation examples include an inlet duct with a rotating compressor and a model helicopter with rotating blades. Such simulation results allow a detailed interpretation of the various scattering phenomenologies for radar target identification applications. © 1994 John Wiley & Sons, Inc.
Transient electromagnetic modeling with the generalized K‐space (GkS) method
Authors: Liu Qing‐Huo 
Published: July 2007

AbstractA centralized k‐space (GkS) method is developed for transient electromagnetic modeling. This method consists of the solution of two equations: (1) the scattering equation in the spectral‐time < k − t) domain, and (2) the constitutive equation in the spatial‐time (r − t) domain. Both are derived as local algebraic equations, and therefore can be solved with O(N) operations. The connection between the r − t domain and k − t domain is obtained by the spatial FFT algorithm. Therefore, in each time step, the number of complex multiply‐add operations is O(N Iog2 N), and the storage requirement is O(N). Because it treats the spatial derivatives by Fourier transform, the k‐space method, compared to the finite‐difference method, provides a high‐order accuracy for the same discretization. It is shown that with the same accuracy requirement, the GkS method requires much fewer unknowns than the conventional finite‐difference method. © 1994 John Wiley & Sons, Inc.
Isotropic chiral composite modeling: Comparison between analytical, numerical, and experimental results
Authors: Mariotte F. , Tretyakov S. A. , Sauviac B. 
Published: July 2007

AbstractElectromagnetic properties of artificial isotropic chiral composites are calculated based on the analytical antenna model for the polarizabilities of small bianisotropic wire‐and‐loop particles and on a numerical simulation technique. Averaged media parameters are estimated using the Maxwell‐Gamett model. Theoretical results are compared with the transmission coefficients for a composite slab measured at microwave frequencies. The analytical model is seen to provide an accurate description in the area of the first resonance of the structure and at lower frequencies, which corresponds to the approximations made in the theoretical modeling. © 1994 John Wiley & Sons, Inc.
Analytic solutions for the ac resistance and internal inductance of a superconductive circular two‐wire transmission line
Authors: Wang Bing‐Zhong 
Published: July 2007

AbstractIn this article, under the quasi‐TEM assumption, using the two‐fluid model and the London equations, and through an exact electromagnetic field analysis, we get an analytic solution for the current density inside the superconductors of a superconductive circular two‐wire transmission line. Finally, the analytic solutions for its ac resistance and internal inductance are obtained.
Determinations of normalizing input/output impedances to apply to parameter conversions for terminated microwave transistors
Authors: Bor Sheau‐Shong , Yeh Shu‐Ming , Liu Ji‐Chyun 
Published: July 2007

AbstractWe propose a practical technique to determine the normalizing input/output impedances by a couple of terminated conditions. The realized quantity of the normalizing input/output impedances could be applicable in the design and implementation of microwave amplifiers.
A higher‐order surface boundary condition for a dielectric substrate backed by a nonperfect conductor
Authors: Cicchetti Renato 
Published: July 2007

AbstractA higher‐order surface impedance boundary condition (HOIBC) for a dielectric substrate backed by a nonperfect conductor is presented. The boundary condition is derived first in the spectral two‐dimensional Fourier domain, and later in the space domain. It is shown that in the space domain such a condition is expressed by a dyadic operator acting on the tangential components of the magnetic field. Finally, in order to demonstrate the qualities of the proposed HOIBC, a comparison of the field radiated by a horizontal electric dipole (HED) placed on the considered structure, computed using the exact and the approximated (higher‐order) impedance boundary condition (IBC), has been presented.
High extinction ratio metal‐clad GaAs/GaAIAs waveguide polarizer
Authors: Saini Mamta , Gupta V. L. , Sharma Enakshi K. 
Published: July 2007

AbstractWe present the design of an extremely high extinction ratio metal‐clad GaAs/GaAlAs TE‐pass polarizer with the buffer layer also of GaAlAs. Our investigations on the effect of the buffer layer index on the extinction of TM modes show that high index buffers corresponding to GaAlAs can give an extremely high TM loss by a suitable choice of Al concentration. The choice of this type of buffer also eliminates the depositon step, during device fabrication, required for materials like SiN and oxide buffer layers reported earlier.
Design, realization, and evaluation of a millimeter‐wave network analyzer using a single six‐port reflectometer
Authors: Abou Chahine S. , Huyart B. , Bergeault E. , Jallet L. 
Published: July 2007

AbstractThis work presents an automatic network analyzer (ANA) using a single six‐port reflectometer in the W frequency band (75‐110 GHz). Its analysis, design, and testing are described. A calibration procedure requiring two standards and a new calibration technique are used to determine the full scattering parameters of the device under test (DUT). Finally, a comparison between experimental results performed with the six‐port network analyzer and the other measurement systems available in the W frequency band is presented.
A simple technique for the design of gaas mmic double side‐band modulators based on the gilbert cell
Authors: Alonso José I. , Sánchez Juan C. 
Published: July 2007

AbstractA theoretical analysis of the Gilbert cell has been performed in order to accomplish a simple design method that allows us to choose the gate width and the bias point of its MESFET transistors as well as its load resistor RL; also, the frequency dependence on differential output voltage can be analyzed. A wideband (1‐4‐GHz) double side‐band (DSB) modulator has been designed and built using this method. This DSB modulator is comprised of an input differential amplifier, a Gilbert cell, and an output differential amplifier, and it has been implemented with the 0.5‐μm F20 process of GEC‐Marconi. A carrier rejection of 50 dB and a third‐order intermodulation rejection of 48 dB have been measured at 2 GHz. The dc power consumption of the Gilbert cell is 136 mW.
Asymptotic closed‐form representation of the spatial microstrip dyadic green's function
Authors: Popovski Borislav , Toscano Alessandro , Vegni Lucio 
Published: July 2007

AbstractAn asymptotic closed‐form representation of the spatial microstrip dyadic Green's function is developed. This representation is very efficient for a numerical evaluation of the field when the source and the observation points are laterally rather than vertically separated with respect to the interface plane. Numerical examples are presented that indicate that the representations obtained are very efficient even for relatively small lateral separation of the source and field points. This work is especially useful in the moment‐method analysis of microstrip antenna arrays where the mutual coupling effects are important.
Analysis of a microstrip‐line‐fed radiating slot on a cylindrical surface
Authors: Tsai Ruenn‐Bo , Wong Kin‐Lu , Su Hsin‐Cheng 
Published: July 2007

AbstractThis article presents an analysis of a microstrip‐line‐fed radiating slot on a cylindrical surface. The reciprocity theorem is applied in this analysis, and the Green's functions for the structure studied here are derived and used in the moment‐method calculation for obtaining the slot impedance, which can be viewed as an equivalent series impedance at the slot position as seen by the microstrip line. Numerical results of the slot impedance for various cylinder radii are calculated, and the curvature effects on the slot impedance are discussed. The radiation pattern of the radiating slot is also calculated and presented. © 1995 John Wiley & Sons. Inc.
3D FEM simulation and experimental measurements of microwave microstrip dielectric‐resonator filters
Authors: Chuang H.‐R. , Huang J.‐W. , Wei C.‐C. , Chang Jason L. C. 
Published: July 2007

AbstractThree‐dimensional numerical simulation of the complete structure and experimental measurements of a microstrip dielectric‐resonator bandpass filter (MDR‐BPF) are presented. The numerical simulation was performed by using the 3D finite‐element method (FEM). A bandpass filter using two dielectric resonators (DRs) in a rectangular metallic enclosure coupled through microstrip lines has been realized around 6.55 GHz. Numerical results and measured data are compared. Good agreements are achieved. The change percentage of the filter passband frequency as a function of the DR dielectric constant were investigated. © 1995 John Wiley & Sons. Inc.
An optically preamplified PPM intersatellite system described by a moment‐generating function formulation
Authors: Phillips A. J. , Cryan R. A. , Senior J. M. 
Published: July 2007

AbstractAn original analysis, facilitated by the use of Chernoff bound techniques, is presented for an optically preamplified satellite PPM system employing a receiver that integrates over a time slot and compares the result with a fixed threshold. At 155‐Mbit/s operation we demonstrate a potential receiver sensitivity of 50.7 photons/bit with background noise present. We also compare results with those obtainable from a Gaussian approximation, finding the Gaussian approximation consistently less conservative for the cases considered. © 1995 John Wiley & Sons. Inc.
Simulation of antenna radiation pattern
Authors: Wu Te‐Kao 
Published: July 2007

AbstractAdequately modeling the radiation pattern of a high‐performance antenna system usually requires the expensive development of complicated electromagnetic software or the storage of an extremely large number of measured data. An alternative and efficient simulation technique is described in this article using a spherical wave expansion model, which requires the storage of a relatively small number of coefficients to define the function for the antenna's radiation pattern. © 1995 John Wiley & Sons. Inc.
Efficient spectral‐domain analysis of open asymmetrical multiconductor transmission lines
Authors: Coetzee J. C. 
Published: July 2007

AbstractThe dispersion characteristics of open, asymmetrical planar structures may be obtained through the iterative solution of an eigenvalue equation in the spectral domain. During each iteration, a number of terms need to be calculated by means of numerical integration over an infinite range. In this article techniques for the treatment of slow‐converging integrals are described. © 1995 John Wiley & Sons. Inc.
Analysis of a slot‐coupled cylindrical‐rectangular microstrip antenna
Authors: Huang Chih‐Yu , Wong Kin‐Lu 
Published: July 2007

AbstractThe input impedance of a slot‐coupled cylindrical‐rectangular microstrip antenna is studied. Based on an equivalent circuit derived using the generalized transmission‐line model (GTLM) theory and taking into account the impedance transformations proposed previously for the analysis of a slot‐coupled microstrip antenna, the input impedance is readily calculated. Numerical results of the input impedance for some antenna parameters are presented and discussed © 1995 John Wiley & Sons. Inc.
Equivalent edge current technique for reflector antenna patterns in the boresight caustic region
Authors: Rengarajan Sembiam R. , Lyerly Albert E. , Villaseca Eduardo H. 
Published: July 2007

AbstractIt is shown that the equivalent edge currents (EEC) obtained in terms of the uniform geometrical theory of diffraction coefficients (EEC‐UTD) yield accurate values of the radiated far field in the boresight caustic region of a paraboloid. Failure of the equivalent edge current technique to provide the correct values for boresight region fields in a previous article is attributed to the reflector edge representation in that article. Radiation patterns computed by the EEC‐UTD method are found to blend well with the pattern obtained by the UTD technique. © 1995 John Wiley & Sons. Inc.
Poynting's theorem for the finite‐difference–time‐domain method
Authors: De Moerloose Jan , De Zutter Daniel 
Published: July 2007

AbstractA discretized version of Poynting's theorem is rigorously derived from the standard FDTD equations. By using the correct averaging expressions for the Poynting vector itself, the energy density, and the current power density, the well‐known form of the theorem in continuous space is obtained. The theorem is checked by calculating the radiated power of an antenna in two ways. It is also shown that the use of nonstandard FDTD equations for thin wires violates the theorem. © 1995 John Wiley & Sons. Inc.
Time‐domain analysis of transmission lines with arbitrary nonlinear loads
Authors: Yun Chan‐Eui , Ra Jung‐Woong 
Published: July 2007

AbstractA direct time‐domain method is presented for calculating voltage waves at terminals and on transmission line terminating in an arbitrary nonlinear load. By utilizing a time stepping of the load voltage with a sufficiently small time interval, one may linearize the nonlinear load in that interval and obtain the convergent voltage responses. Numerical examples show that this is efficient in the computation without the use of the inverse Fourier transform or the Newton‐Raphson method for the lossy transmission line. © 1995 John Wiley & Sons. Inc.