bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quasioptical SMMW resonator with extremely high Q factor
Authors: Steup Dominik 
Published: July 2007

AbstractA quasioptical resonator for the frequency range between 170 and 260 GHz and a Q factor of more than 50,000 has been built. We use a semiconfocal resonator that is tunable in resonance and has a passive temperature stabilization. The coupling in of electromagnetic energy is realized using metallic meshes with quadratic apertures and polarizing wire grids as well. The resonator is tuned by moving the spherical mirror with a piezo driver. © 1995 John Wiley & Sons. Inc.
Design of multilayer frequency‐selective surface for diplexing two closely spaced channels
Authors: Cahill R. , Parker E. A. , Antonopoulos C. 
Published: July 2007

AbstractA frequency‐selective surface consisting of three arrays of ring elements is analyzed. It is shown that broad transmission and reflection bands can be generated with separation ratios of less than 1.03:1. Measurements confirm that the diplexer performance is relatively insensitive to the angle and plane of incidence. © 1995 John Wiley & Sons. Inc.
A dual‐frequency antenna using a single patch and an inclined slot
Authors: Antar Y. M. M. , Ittipiboon A. I. , Bhattacharyya A. K. 
Published: July 2007

AbstractResults on a dual‐frequency microstrip patch antenna fed by using an inclined slot in the ground plane of a microstrip line are described. The frequencies of operation are determined by choosing the dimension of the rectangular patch and by adjusting the inclination angle of the slot. The antenna is easy to construct and results obtained from an antenna designed to operate around 9 and 12 GHz are presented. © 1995 John Wiley & Sons. Inc.
Tunable ring resonator filter for OFDM transmission systems
Authors: Vázquez C. , Hernández‐Gil F. , López‐Amo M. 
Published: July 2007

AbstractA novel tunable filter is theoretically demonstrated. It is based on a ring resonator with an amplifier and a noise filter in the loop. This optoelectronic device has potential as a high‐sensitivity receiver and as a tunable demultiplexer in OFDM transmission systems. © 1995 John Wiley & Sons. Inc.
Overcoming the onset of ill conditioning at interior resonances by using generalized formulations
Authors: Leviatan Yehuda , Baharav Zachi 
Published: July 2007

AbstractGeneralized formulations, in which instead of solving for the actual surface current one solves for an equivalent fictitious current flowing on a mathematical surface enclosed inside the body, have been used for analysis of many scattering problems. This article explains how inaccuracies occurring at frequencies corresponding to interior resonances of the conducting surface can be avoided by using generalized formulations. A numerical study of TM scattering by a circular cylinder at such resonant frequencies is carried out. The advantage gained by using generalized formulations instead of standard surface formulations in eliminating internal resonances is demonstrated. It is also shown that even if the shape of the interior mathematical surface, when covered by a perfect conductor, forms a resonant cavity, no problem is encountered. © 1995 John Wiley & Sons, Inc.
Comparison between GaAs and AllnAs/GalnAs MSM PDs for microwave and millimeter‐wave applications using a two‐dimensional bipolar physical model
Authors: Ashour I. S. , Vilcot J. P. , Harari J. , Decoster D. 
Published: July 2007

AbstractUsing a 2D bipolar physical model a comparison is made between GaAs and AllnAs/GaInAs MSM PD performance (cutoff frequency and quantum efficiency) as a function of the device parameters. This covers the applied potential, electrode spacing, absorbing layer thickness, and heterojunction effect. We also reported that for millimeter‐wave applications we can expect higher operating frequency using an AlInAs/GaInAs MSP PD, whereas we can expect higher quantum efficiency using a GaAs MSM PD. © 1995 John Wiley & Sons, Inc.
Rigorous hybrid‐mode analysis of an asymmetric coupled shielded dielectric image guide
Authors: Pradhan Lalat K. , Biswas Animesh 
Published: July 2007

AbstractA rigorous hybrid‐mode analysis based on the mode‐matching technique is used for computing the propagation characteristic of a general symmetric coupled shielded dielectric image guide. The validity of the theory is confirmed by comparing the data for a symmetric coupled line as a special case with the reported data available in literature. Then, illustrative numerical results are presented for the coupling characteristics of various cross‐sections of dielectric guides for suitable wideband coupler applications. © 1995 John Wiley & Sons, Inc.
Influence of the background light on the time‐bandwidth product measured on electroabsorption modulators used as soliton sources
Authors: Brindel P. , Hamaide J. P. , Devaux F. , Carenco A. 
Published: July 2007

AbstractTwenty‐picosecond soliton pulses are experimentally generated by an electroabsorption modulator at a 10‐GHz repetition rale. By taking into account the unavoidable background light and the voltage‐dependent chirp parameter, a good agreement between theoretical and experimental results is found. It also appears that the usual time‐bandwidth product specifying such sources must be interpreted with care. © 1995 John Wiley & Sons, Inc.
Modeling and testing of a light‐induced spatial light modulator in hybrid optoelectronic systems
Authors: Wysokiński Tomasz W. , Rawicz Andrew H. , Lȩtowski Stanislaw 
Published: July 2007

AbstractAn adaptive filter/photosensitive detector array system is analyzed for use in image acquisition. Different transmittance characteristic adaptive filter models are investigated and a possible application is suggested. The use of photochromes for passive adaptive filter implementation is postulated. Glass and plastic photochromic adaptive filters are tested to confirm some modeling results. © 1995 John Wiley & Sons, Inc.
Analysis of microstrip discontinuities on suspended and grounded anisotropic substrates
Authors: Cain Jeffrey , Beker Benjamin 
Published: July 2007

AbstractThis article presents a comprehensive numerical study of resonant and nonresonant microstrip discontinuities that are printed on anisotropic substrates. The approach employs the method of moments (MoM), which is implemented for the gap, step, and stub discontinuities for the first time in MICs with other than biaxial anisotropic substrates. Numerical results include the variation of the normalized gap admittances with respect to different material parameters, insertion and transmission loss of step discontinuities, and shifts in resonant frequencies of tuning stubs due to rotation of the principal axes of the substrate. Computed data are validated for every structure against results in previously published literature. © 1995 John Wiley & Sons, Inc.
Led spectral slicing strategies for enhanced dual‐wavelength referencing of intensity sensors
Authors: Senior John M. , Murtaza Ghulam 
Published: July 2007

AbstractA new concept of wavelength thermal matching is described that can be applied to LED‐based dual‐wavelength referenced intensity sensors to achieve compensation for both optical source output fluctuations and variable optical propagation losses. © 1995 John Wiley & Sons, Inc.
Stable transmission of a modulated soliton‐pulse train with soliton transmission control
Authors: Wang Hong , Ye Peida 
Published: July 2007

AbstractThe evolution of the amplitude‐modulated and phase‐modulated soliton‐pulse train in the time and frequency domains under transmission control is numerically investigated. Some discussion and interpretation about the DTS effects are presented. Also some useful conclusions are obtained. © 1995 John Wiley & Sons, Inc.
A finite‐element‐method frequency‐domain application of the perfectly matched layer (PML) concept
Authors: Pekel Ü. , Mittra R. 
Published: July 2007

AbstractThe perfectly matched layer (PML) concept, introduced by Berenger with the aim of synthesizing an absorbing boundary condition (ABC) for the finite‐difference‐time‐domain (FDTD) method, is modified and extended to the frequency domain for FEM applications. The governing equations that characterize this approach require neither the splitting of the field components of interest, nor do they involve negative conductivity parameters. © 1995 John Wiley & Sons, Inc.
Analysis and design of a multichannel HEMT gate mixer
Authors: Allam R. , Kolanowski C. , Théron D. , Crosnier Y. 
Published: July 2007

AbstractThe analysis of the operation of a HEMT gate mixer is presented below. We study the effect of the HEMT nonlinearities on mixer performance by using the nonlinear model in CAD. In particular, the tailoring of an adequate transconductance profile is used to optimize mixer performance for millimeter‐wave realization. © 1995 John Wiley & Sons, Inc.
The effects of biasing and harmonic loading on mesfet tripler performance
Authors: Zhao Guoxiang , El‐Rabaie S. , Ghannouchi Fadhel M. 
Published: July 2007

AbstractThe effects of biasing and harmonic loading on GaAs MESFET tripler performance are studied. The Tajima large‐signal nonlinear model and the harmonic balance approach are used for this purpose. The output power, gain, and efficiency of a 5 ∼ 15‐GHz tripler, as functions of the fundamental and second harmonic load impedances, as well as the gate‐bias voltages, are investigated. Design guidelines for MESFET triplers are deduced. It is recommended, for any biasing, that the fundamental frequency load impedance be an inductive reactance away from the open‐circuit region, and that the second harmonic termination be in the short‐circuit region. © 1995 John Wiley & Sons, Inc.
Phase velocity equalization in microstrip couplers by partial dielectric overlays
Authors: Kouki Ammar B. , Khebir Ahmed , Ghannouchi F. M. 
Published: July 2007

AbstractThe effects of a partial isotropic dielectric overlay on the isolation, coupling, and impedance of a microstrip 10‐dB coupler are studied. Results as functions of the overlay's width, height, and dielectric constant are presented. It is found that a better coupler design can be achieved through proper choice of these three parameters. © 1995 John Wiley & Sons, Inc.
The aperture admittance of a flanged dielectric‐filled waveguide antenna
Authors: Tian M. , Ligthart L. P. 
Published: July 2007

AbstractThe aperture admittance is formulated for a slice dielectric‐filled (ϵr ≥ 1) rectangular waveguide antenna. By considering the specific media discontinuity at the aperture, the formulation is able to predict aperture admittance of the waveguide with various dimension ratios and dielectrics. The summarized results are new in the sense that they have rarely been found in the literature. Calculations and supporting measurements show that the filled dielectric has an important influence, in addition to waveguide height, on the aperture admittance. The proposed approach permits a good simulation of aperture characteristics and impedance matching. © 1995 John Wiley & Sons, Inc.
Performance of a suboptimum PPM presynchronization filtering network
Authors: Hussain A. , Elmirghani J. M. H. , Cryan R. A. 
Published: July 2007

AbstractAn optimum presynchronization filter for the pulse‐position‐modulation (PPM) signal is derived and shown to be comprised of a matched filter in cascade with a derivative network. An original investigation of the performance of the filtered PPM system is presented. The matched filter is realized from a time‐domain specification on the received pulse shape and an RC combination derivative network is used to shape the pulse. The results demonstrate that there exists an optimum value of the differentiating capacitor resulting in performance that is close to the true derivative. The results obtained illustrate a significant improvement in both the timing variance and jitter wrong slot error (JWSE) probability compared to that for the matched filter. © 1995 John Wiley & Sons, Inc.
Inverse scattering of biaxial cylinders
Authors: Chiu Chlen‐Ching , Yang Rong‐Hwa 
Published: July 2007

AbstractThe inverse scattering of inhomogeneous biaxial dielectric cylinders is investigated. Assume that an incident wave is incident upon anisotropic cylinders of unknown dielectric constant distribution, and the scattered field is measured outside. By properly processing the scattered field, the dielectric‐constant distribution of the object can be reconstructed. For the theoretical formulation, based on the proper arrangement of the direction and polarization of the incident field, a set of integral equations that can be solved by the moment method and an unrelated illumination method is derived. Numerical results are given to demonstrate the capability of the inverse algorithm. Good reconstruction is obtained even in the presence of additive random noise in measured data. In addition, the effect of noise in the reconstruction result is also investigated. © 1995 John Wiley & Sons, Inc.
Electrical characteristics of coplanar waveguide devices incorporating nonlinear dielectric thin films of SrTiO3 and Sr0.5Ba0.5TiO3
Authors: Findikoglu A. T. , Jia Q. X. , Reagor D. W. , Wu X. D. 
Published: July 2007

AbstractWe have studied voltage‐tunable (0–200 V) broadband (0.1–5.1 GHz) microwave properties at room temperature and the liquid nitrogen temperature of two coplanar waveguide devices made from a Au / Sr0.5Ba0.5TiO3 bilayer and a YBa2Cu3O7‐x / SrTiO3 bilayer, respectively. The experimental results agree well with the predictions of simple quasistatic and quasi‐TEM models. © 1995 John Wiley & Sons, Inc.
Elimination of the spurious root in the SDA solution to the shielded microstrip problem
Authors: Amari Smain , Børnemann Jens 
Published: July 2007

AbstractWe report that the spurious root that appears in the spectral‐domain approach solution to the shielded lossless and infinitely thin microstrip is eliminated when enough basis functions to accurately describe the transverse current density are used. A fast algorithm based on the observed simple behavior of the minimum singular value of the characteristic matrix as a function of β2 instead of β is presented. For lossless microstrip lines, with small values of the dielectric constant and at relatively low frequencies, two evaluations of the characteristic matrix are sufficient to determine its dispersion properties, when the longitudinal current density is assumed Maxwellian, thus achieving a considerable reduction of CPU time. © 1995 John Wiley & Sons, Inc.
Beam‐propagation‐method analysis of a three‐waveguide nonlinear directional coupler
Authors: Yasumoto Kiyotoshi , Maeda Hiroshi , Nakamura Kouichi 
Published: July 2007

AbstractThe power‐transfer characteristics of a three‐waveguide nonlinear directional coupler (NLDC) are investigated with the beam‐propagation method based on the finite‐difference scheme. The coupler consists of two outer linear waveguides and a center waveguide with a nonlinear Kerrlike medium. It is shown that the three‐waveguide NLDC is useful for constructing a power‐dependent power divider, a power‐dependent power combiner, and an optical logic element. © 1995 John wiley & Sons, Inc.
Design of metal‐semiconductor‐metal photodetector array with uniform 3‐dB bandwidth
Authors: Liu Qing Z. 
Published: July 2007

AbstractDetailed computer simulations were carried out in order to fully understand the position‐dependent 3‐dB bandwidth variation of an metal‐semiconductor‐metal photodetector (MSM‐PD) array in bus configuration. It was found that the 3‐dB bandwidths of the detectors in the array are different, mainly due to the equivalent inductance of the bus metal trace. It is shown that there exists an optimal length of metal trace between two consecutive MSM‐PDs, which results in an equal 3‐dB bandwidth of the MSM‐PD array. © 1995 John Wiley & Sons, Inc.
An alternate form of the MUR second‐order absorbing boundary condition
Authors: Rahhal‐Arabi Ahmad , Mittra Raj 
Published: July 2007

AbstractThe Mur absorbing boundary conditions (ABCs) are used very widely for the truncation of the finite‐difference mesh. The purpose of this note is to present an alternate form of the second‐order Mur absorbing boundary condition. It has a more compact form and can be viewed as a special case of the second‐order dispersive boundary condition. This compact form is not only simple to implement, but also requires less computational time. © 1995 John Wiley & Sons, Inc.
TE‐TM source decomposition for general uniaxial bianisotropic media
Authors: Olyslager Frank , Jakoby Bernhard , Lindell Ismo V. 
Published: July 2007

AbstractIn the present contribution we study the decomposition of a source into transverse electric (TE) and transverse magnetic (TM) parts in general uniaxial, bianisotropic media. We use a spatial Fourier transform with respect to the axial direction to derive the decomposition in the Fourier domain first. In a next step an analytical inverse transform is performed to obtain the space‐domain result. It is shown that in general the decomposition of a source that occupies a finite region fills up the whole space. It is further shown that our results contain the previously published results for uniaxial anisotropic materials as special cases. © 1995 John Wiley & Sons, Inc.
A new modulation technique based on digital pulse interval modulation (DPIM) for optical‐fiber communication
Authors: Ghassemlooy Z. , Kaluarachchi E. D. , Reyher R. U. , Simmonds A. J. 
Published: July 2007

AbstractA novel digital pulse time modulation (PTM) technique called digital pulse interval modulation (DPIM) is presented, in which the input signal information is transmitted by the time intervals between two succeeding pulses. DPIM has simplicity of circuit configuration combined with other attractive features of digital pulse position modulation (DPPM) for optical‐fiber communications. This article derives theoretical expressions for transmission capacity, code characteristics, and power spectral density (PSD), and the analytical results are compared with experimental data. © 1995 John Wiley & Sons, Inc.
Efficiency of lossless power combiners
Authors: Eccleston K. W. 
Published: July 2007

AbstractThis article will examine the combining efficiency of a lossless power combiner where port mismatch and interinput port coupling are considerable. A derived lower bound for combining efficiency is compared with simulation results. It is shown that the combining efficiency of a lossless combiner is maximized when the combiner output match is optimized. © 1995 John Wiley & Sons, Inc.
Finite‐difference — time‐domain analysis of a high‐frequency microwave connector
Authors: Chen Yinchao , Shimony Yuval , Harms Paul , Mittra Raj 
Published: July 2007

AbstractIn this study, the finite‐difference‐time‐domain method (FDTD) is used to analyze a complex packaging component, namely, a high‐frequency microwave connector. Because the FDTD technique is easy to use and very flexible, it can be employed to analyze packaging components whose geometrical configurations are highly complex. In contrast, other approaches, for example, the method of moments (MoM), the method of lines (MoL), and the finite‐element method (FEM), are more difficult to apply to complex geometries. In this article we employ the FDTD method to investigate the scattering parameters of a microwave connector and validate the numerical results by comparing them with measured data. © 1995 John Wiley & Sons, Inc.
An improved gaussian approximation for optically preamplified PPM systems including the effect of timing jitter
Authors: Phillips A. J. , Cryan R. A. , Senior J. M. 
Published: July 2007

AbstractThe effect of timing jitter is evaluated using an improved Gaussian approximation for an optically preamplified PPM receiver. For the parameters considered a potential sensitivity of 23.6 photons/bit is demonstrated in the unjittered case with the jittered optimum at worst only 1 dB less sensitive. Both these results surpass the fundamental sensitivity limit of an OOK NRZ system. The analysis predicts that wrong‐slot and jitter errors first become dominant at a coding level higher than that suggested by an earlier model. © 1995 John Wiley & Sons, Inc.
Prediction of the average power of cross‐talk effects in multiconductor transmission lines
Authors: Linaresy M R. , Kontorovich V. Ya. , Jardón A. H. 
Published: July 2007

AbstractThis article presents an efficient model for the prediction of cross‐talk effects on generator wires and on both the near and far ends of receptor wires of multiconductor transmission lines. The parameter of interest is the average power output of the generator wire, where all effects of multiconductor transmission‐line parameters are included and the cross talk on the receptor wire is also estimated. This model was used in a printed circuit board (PCB) with microstrip lines, and good agreement between theory and measurements was obtained. © 1995 John Wiley & Sons, Inc.
Parameter estimation of frequency‐dependent scatterers using superresolution techniques
Authors: Odendaal J. W. , van Jaarsveld P. A. 
Published: July 2007

AbstractA technique to estimate the frequency dependence of electromagnetic scattering centers is proposed. The technique employs a superresolution algorithm to estimate poles corresponding to the various scattering centers contributing to the total backscattered field. A relationship between the amplitudes of the estimated poles and the frequency dependence of the scatterers is derived. The technique is applied to estimate the frequency dependence of simulated and measured backscattered field data. © 1995 John Wiley & Sons, Inc.
A study on the pattern‐forming synthesis of a hemielliptical conformal‐array antenna
Authors: Hashimoto Osamu , Nobori Kanichi , Nishizawa Shinichiro 
Published: July 2007

AbstractIn this article a new pattern‐forming synthesis for an arbitrary conformal‐array antenna is shown. Using this method, various antenna patterns of hemielliptical array for varying the ratio of vertical and horizontal length and number of elements are calculated. As a result, it is confirmed that the side‐lobe level is almost suppressed within the desirable level by using the optimum number of elements. © 1995 John Wiley & Sons, Inc.
Modified analysis of conical horns
Authors: Bornemann Jens 
Published: July 2007

AbstractA modified analysis of conical horns ispresented that takes into account the true phase relationships between the feeding waveguide, the conical horn section, and the aperture phase variation. It is demonstrated that, especially for low‐gain applications, an accurate account of the aperture phase error results in higher gains than those obtained by widely used design methods‐or that a slightly shorter horn is obtained for identical gain specifcations. Comparisons with measured data reveal the advantage of this relatively simple analysis compared with techniques involving the conical waveguide mode spectrum. © 1995 John Wiley & Sons, Inc.
Study of a circularly bent slab waveguide as a limiting case of a waveguide of large annular cross section
Authors: Choudhury P. K. , Shukla P. K. , Khastgir P. , Ojha S. P. 
Published: July 2007

AbstractIn this article an analytical investigation has been made of a slab waveguide with a small circular deformation across the direction of wave propagation. The resulting guide can be considered as a waveguide having a large annular cross section. Using the approximation of vanishing refractive index difference between the guiding and the nonguiding regions, fractional powers have been estimated that flow individually through these regions. © 1995 John Wiley & Sons, Inc.