bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of polarization‐preserving circular waveguide filters with attenuation poles
Authors: Amari Smain , Bornemann Jens 
Published: August 2002

AbstractBandpass filters in circular waveguide technology are designed to have enhanced stopband responses. Highly dispersive coupling sections are introduced to replace regular circular irises. The resulting direct‐coupled resonator bandpass filters have the advantage of preserving the polarization of the incident excitation while providing sharp cutoff skirts. Attenuation poles at finite frequencies are generated on either side of the passband by using radial stubs, which also perform the role of inverters. In contrast to the pole‐extraction technique, or the classical technique of using stubs for the sole purpose of pole generation, the zero‐generating elements act as inverters, and are not necessarily the first elements at the input and/or output. A simple approximate design technique which provides adequate starting values for optimization‐based design is also introduced. Design examples are presented to show the validity of the approach and the performance of these filters. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 334–336, 2001.
Coplanar propagation on magnetic substrates
Authors: Hinojosa Juan 
Published: August 2002

AbstractAnalytical relationships and graphs are represented for the effective relative permeability, filling factors, and characteristic impedance of magnetic substrates for coplanar lines. The determination of these analytical relationships was obtained from Veyres' formulas for dielectric substrates and Pucel's duality relationship between magnetic and dielectric substrates. The graphs are discussed, and analytical relationships are validated. These analytical relationships represent a suitable set for the design of coplanar lines for hybrid and monolithic MICs (microwave integrated circuits). © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 365–368, 2001.
A planar inverted‐L patch antenna for 2.4/5.2 GHz dual‐band operation
Authors: Kuo Yen‐Liang , Wong Kin‐Lu 
Published: August 2002

AbstractA new design of a dual‐band planar inverted‐L patch antenna suitable for applications in WLAN (2400–2484 MHz) and HIPERLAN (5150–5350 MHz) systems is proposed. By using an inverted‐L radiating patch, in which two additional narrow slits are inserted at the radiating edge to effectively control the excited patch surface current distributions, the proposed antenna can generate two operating frequencies at 2.4 and 5.2 GHz. In addition, wide impedance bandwidths are obtained. The proposed antenna has 10 dB return‐loss bandwidths of 7.5 and 8.1% in the 2.4 and 5.2 GHz bands, respectively, and the obtained peak antenna gain also reaches 5.7 and 6.4 dBi for operating frequencies within the 2.4 and 5.2 GHz bands, respectively. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 394–396, 2001.
Broadband hybrid microstrip couplers—Amplitude and phase
Authors: Queck Cham Kiong , Davis Lionel E. 
Published: August 2002

AbstractSeveral designs for a 180° hybrid coupler are discussed. Using the stepped‐impedance method, the bandwidth of an 11 GHz hybrid coupler is increased to approximately 1.6 times the bandwidth of a conventional hybrid coupler. Comparisons are made between conventional and broadband hybrid couplers, as well as between circular and rectangular designs, and the phase behavior of each is compared for the first time. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 254–259, 2002.
Electromagnetic scattering from nonuniform magnetized ferrite cylinder
Authors: Hu B. J. , Yung E. K.‐N. , Sheng X. Q. 
Published: August 2002

AbstractAn analytical technique, called the scattering matrix method, is developed to analyze the scattering of a plane wave from a nonuniform ferrite cylinder. It is proved that the derived formulas for nonuniform ferrite cylinders can be degenerated to the formulas for uniform ferrite cylinders published in the literature. The characteristics of scattering by ferrite cylinders with a linear profile are investigated versus applied magnetic fields and wave frequencies. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 268–272, 2002.
BER analysis of synchronous fiber‐optic CDMA networks with suboptimal decision threshold
Authors: Kuo Ching‐Chih , Wu Jyh‐Horng 
Published: August 2002

AbstractThe bit‐error rate (BER) of synchronous optical CDMA networks with a fixed (suboptimal) decision threshold is derived. The strategy used offers the advantage that the network need not dynamically monitor the number of users. The numerical results are satisfactory when compared with previous literature based on an optimal threshold. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 293–296, 2002.
Fast computation of FET power gains
Authors: Paoloni Claudio 
Published: August 2002

AbstractPower gain definitions are fundamental parameters in the design of FET small‐signal amplifiers. In this Letter, a simple and direct method to compute the various gain definitions of FET up to 60 GHz is demonstrated. A set of simple equations to compute the S parameters from the FET complete π model are used. The power gain definitions are calculated from the S‐parameter modules derived from these equations. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 104–106, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10235
Material imaging with the use of a microwave cavity perturbation technique
Authors: Zürcher J‐F. 
Published: August 2002

AbstractA measurement method using a microwave cavity perturbation technique is described. It allows high‐quality imaging of various materials, ranging from metals to dielectrics and biological objects. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 106–112, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10246
Extraction of lumped‐element equivalent‐circuit models of microstrip discontinuities using the finite‐difference time‐domain method
Authors: Farahat Nader , Yu Wenhua , Mittra Raj 
Published: August 2002

AbstractThis Letter presents a method for extracting the lumped‐element equivalent‐circuit models of microstrip discontinuities by using the finite‐difference–time‐domain (FDTD) method. The cascading properties of the ABCD matrix are used to de‐embed the attachment lines, leading to the two‐port matrix of the discontinuity section alone. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 132–134, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10254
Statistical construction of accurate CAD models using measured data
Authors: Naishadham Krishna , Leiker William 
Published: August 2002

AbstractComponent models available in CAD software do not consider the statistical variation and the layout‐ or package‐specific parasitic effects of components. Because of the complexity of device packages, the well‐established EM simulation alternative can only be applied to relatively simple circuits. This Letter presents a methodology to construct statistically a representative component model from a measured database, and show how such a model can be used in a circuit simulator for effective circuit design. All the parasitic effects of the circuit components are incorporated through measurements. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 233–238, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10284
Fundamental study of a λ/4 wave absorber using FSS for two frequencies
Authors: Itou Akihiko , Wada Kouji , Hashimoto Osamu 
Published: August 2002

AbstractThe aim is to study basic characteristics of a frequency selective surface (FSS) for two frequencies and its application to the wave absorbers using the FSS for two frequencies, which are fabricated by two absorption films. In this study, the shielding characteristics with the frequency‐selection by FSS, absorption, and shielding characteristics of the proposed wave absorber using FSS are examined experimentally. Good performance of the FSS and the wave absorber using FSS were obtained, as expected. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 321–322, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10308
Component synthesis in optoelectronics modelling
Authors: Sewell P. , Vukovic A. , Benson T. M. 
Published: August 2002

AbstractA CAD package was developed that accepts a functional design specification for a multilayered optical slab waveguide and returns a physical description of a structure in a form immediately suitable for fabrication. It is shown that the definition of a figure of merit for the design requires that the importance of the design criteria be suitably weighted. The implications of the present work for the synthesis of more general optoelectronic components and circuits are discussed. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 325–327, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10310
Novel model for the estimation of radiation emission from printed circuit boards with narrow ground pattern
Authors: Chen I‐Fong , Hsue Ching‐Wen 
Published: August 2002

AbstractA circuit model, based on TEM assumption, is provided for estimating the radiation emission of a typical PCB geometry, namely, microstrip. We find that an imperfect ground trace will lead to an unbalanced circuit and radiate EM energy significantly. Measured data are presented to confirm the results of theoretical study. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 332–335, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10313
Frequency‐dependent expressions for inductance and resistance of microstrip line on silicon substrate
Authors: Ymeri H. , Nauwelaers B. , Maex Karen , De Roest D. , Vandenberghe S. 
Published: August 2002

AbstractA new closed‐form expression to calculate frequency‐dependent distributed inductance and the associated distributed series resistance of microstrip lines on a lossy silicon substrate (CMOS technology) are presented. The proposed analytic model for series impedance is based on a self‐consistent field method and the vector magnetic potential equation. It is shown that the calculated frequency‐dependent distributed inductance and the associated resistance are in good agreement with the results obtained from rigorous full wave solutions and CAD‐oriented equivalent‐circuit modeling approach. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 349–352, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10318
New method of timing jitter measurement in soliton communication systems
Authors: Avagyan Razmik , Daryan Ara , Divanyan Edward , Hovhannisyan Davit , Kalayjian Zaven , Meghavoryan David , Stepanyan Komitas 
Published: August 2002

AbstractA mathematical description of the spectral and temporal changes in a probe pulse occurring as a result of cross‐phase modulation interaction between the probe pulse and a soliton with a nonoverlapping spectrum and different delay copropagating in a single‐mode fiber was obtained. We show that information on the time delay between a soliton and a probe pulse can be extracted by analyzing the probe pulse spectral density distribution. This information can be used to measure timing jitter in a soliton communication systems. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 361–365, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10322
Long‐wavelength strained‐layer InGaAs/GaAs quantum‐well lasers grown by molecular beam epitaxy
Authors: Piwoński T. , Sajewicz P. , Kubica J. M. , Zbroszczyk M. , Regiński K. , Mroziewicz B. , Bugajski M. 
Published: August 2002

AbstractThe operation in the 1020 nm wavelength range of strained‐layer InGaAs/GaAs separate‐confinement‐heterostucture lasers grown by molecular beam epitaxy is reported. The active region is formed by a single 80 Å thick InGaAs quantum well with an indium content of 25%, which is close to critical parameters. This paper provides the operating characteristics of broad‐area uncoated Fabry–Perot structures with cavities of 700 μm length measured in the pulsed regime. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 75–77, 2001.
Superconducting lumped‐element filter with spiral inductors
Authors: Barinov A. E. , Zhgoon S. A. , Sukhov V. A. , Su H. T. , Lancaster M. J. , Huang F. 
Published: August 2002

AbstractThis paper presents theoretical and experimental results for a novel three‐pole HTS lumped‐element narrowband filter with central frequency 1.7775 GHz and 0.84% fractional bandwidth. A high degree of miniaturization is reached by the use of planar coils as inductance elements. Good performance on YBCO devices has been achieved. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 94–95, 2001.
Pseudospectral time‐domain algorithm applied to electromagnetic scattering from electrically large objects
Authors: Fan Guo‐Xin , Liu Qing Huo 
Published: August 2002

AbstractThe pseudospectral time‐domain (PSTD) algorithm is extended to model the electromagnetic scattering from both 2‐D and 3‐D objects. The plane‐wave excitation and the time‐domain near–far field transforms in the stretched coordinates are efficiently incorporated into the scattered‐field PSTD algorithm. Numerical results demonstrate the effectiveness of the algorithm in wave‐scattering problems. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 123–125, 2001.
An analytical study of the cutoff conditions and dispersion curves of an optical fiber with a core slightly flattened on one side
Authors: Joshi M. , Singh Vivek , Prasad B. , Ojha S. P. 
Published: August 2002

AbstractIn this paper, we present a simple analytical method based on coordinate transformation for the calculation of the dispersion characteristics of an optical fiber which is slightly flattened on one side. We choose the new and appropriate orthogonal coordinates (ξ, η, z) for the proposed waveguide structure, and impose the boundary condition under a weak guidance condition to obtain the modal eigenvalue equation. Using this equation, we achieve numerical results in the form of dispersion curves and cutoff frequencies. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 136–139, 2001.
A new MESFET nonlinear model
Authors: Ooi B. L. , Ma J. Y. , Leong M. S. 
Published: August 2002

AbstractIn this paper, a new empirical model for the dc I–V characteristics of a GaAs MESFET transistor is presented. The conventional approach for modeling the dc I–V characteristics of a MESFET transistor adopts the hyperbolic‐tangent dependence on Vds through the observation of the Ids versus Vds curve. The derived model is capable of accurately modeling the device current–voltage behavior in different operation regions. The new model equations describe the device drain current as a polynomial of the effective gate–source voltage Veff, which is in turn a rational function of Vgs, and the parameters for the polynomial vary with Vds. Model parameter extraction is made for a 0.5 μm gate‐length MESFET device. Measured and modeled results are compared, and good agreement is obtained. A comparison among the proposed model, Curtice's and Chalmers' model, and Parker's model are also made in this paper. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 226–230, 2001.
Slot‐line‐excited equilateral‐triangular dielectric resonator antenna of very high permittivity
Authors: Lo H. Y. , Leung K. W. , Luk K. M. 
Published: August 2002

AbstractA slot‐line‐excited equilateral‐triangular dielectric resonator antenna (DRA) of very high permittivity (εr=82) is investigated experimentally. The triangular DRA is operated at its fundamental broadside TM1, 0, −1‐mode. An improved bandwidth of ∼5%, which is 1.7 times higher than in the previous aperture‐coupled version, is obtained for the new configuration. The return loss, radiation patterns, and antenna gain of the new configuration are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 230–231, 2001.
The forward–backward method with a novel spectral acceleration algorithm (FB/NSA) for the computation of scattering from two‐dimensional large‐scale impedance random rough surfaces
Authors: Torrungrueng D. , Johnson Joel T. 
Published: August 2002

AbstractThe forward–backward method with a novel spectral acceleration algorithm (FB/NSA) has been shown to be a very efficient 𝒪(Ntot) iterative method of moments, where Ntot is the total number of unknowns to be solved, for the computation of electromagnetic wave scattering from two‐dimensional (2‐D) perfectly conducting rough surfaces. In this paper, the method is extended to treat impedance rough surfaces. It is found that the 2‐D NSA algorithm for the impedance case is similar to the one for the perfectly conducting case. Comparisons of numerical results between the standard 2‐D FB and 2‐D FB/NSA methods show that the latter yields very accurate results with an appreciable reduction of CPU time. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 232–236, 2001.
Reduced‐sidelobe millimeter‐wave broadband antenna
Authors: Kumar Ashwani , Pal Ram , Sudhir H. 
Published: August 2002

AbstractA broad frequency‐band millimeter‐wave antenna working over 18–40 GHz has been designed and developed to realize low‐sidelobe fan‐beam radiation patterns. The antenna system consists of a cylindrical parabolic reflector fed by an offset double‐ridged horn antenna feed. This type of antenna finds extensive use as a rotary direction‐finding (RDF) system in electronic warfare applications. The design approach and measured results for the antenna over 18–40 GHz have been presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 245–248, 2001.
Synthesis and design of N‐order filters with N‐transmission zeros by means of source–load direct coupling
Authors: Montejo‐Garai José R. , Rebollar Jesús M. 
Published: August 2002

AbstractAn extension is made to the synthesis of microwave filters with cross couplings between nonadjacent cavities to the case where there is a direct coupling between the input and output ports, i.e., the source and the load of the device. This coupling extends to N‐order filters the possibility to accomplish responses with N finite transmission zeros. In addition, symmetric and asymmetric rejection slopes out of band and equalized group delay can be obtained simultaneously. Several examples of filter synthesis are presented to validate the proposed synthesis procedure. Finally, to show the applicability of the load–source direct coupling, a second‐order Ku‐band filter with two transmission zeros has been designed using three physical structures: two different rectangular waveguide E‐plane configurations and one H‐plane. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 248–252, 2001.
Gain calculations in erbium‐doped fibers using field approximations
Authors: Sunanda  , Jain Geetika , Sharma Enakshi Khular 
Published: August 2002

AbstractIn this paper, we compare the use of various field approximations of modal fields for gain calculations in erbium‐doped fibers. Our results show that the use of an appropriately chosen rectangular approximation leads to simple analytical expressions for the gain characteristics, and still retains sufficient accuracy. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 256–259, 2001.
Interference reduction in synchronous fiber‐optic PPM–CDMA systems
Authors: Lee T. S. , Shalaby H. M. H. , Ghafouri‐Shiraz H. 
Published: August 2002

AbstractA pulse‐position modulation (PPM) optical CDMA system with interference estimation and cancellation is proposed. Multiuser interference is estimated with the aid of modified prime code sequence properties. A comparison between the bit‐error rate (BER) of both the proposed system and the system without cancellation reveals that the former system improves the BER performance significantly. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 202–205, 2001.
Light guiding in optical fibers with Kerr‐like nonlinearity
Authors: Romanova Elena A. , Melnikov Leonid A. , Bekker Ella V. 
Published: August 2002

AbstractGuiding properties of optical fiber with Kerr‐like nonlinearity are studied numerically using the finite‐difference beam‐propagation method to solve the scalar‐wave equation. The nonlinear fiber is shown to support fields with longitudinally invariant radial distributions having a mean‐squared beam width less than that of the linear fiber mode. The double‐mode propagation is shown to be unstable, and tends to convert into single‐mode propagation after some distance from the input endface of the fiber. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 212–216, 2001.
Three‐dimensional optical tomography of incomplete data
Authors: Zhengdong Wang , Zhixing Wang , Zhenhua Li , Anzhi He 
Published: August 2002

AbstractIn this paper, three‐dimensional optical computerized tomography in the case of severely incomplete projection data is discussed theoretically and experimentally. An orthogonal projection method has been proposed for optical tomography in the case of severely incomplete data. Some comparative numerical simulations and experimental results of traditional sampling method and the new method are given. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 57–59, 2001.
Bias correction and yield optimization of MMICs with external digital control
Authors: Scotti Giuseppe , Tommasino Pasquale , Trifiletti Alessandro 
Published: August 2002

AbstractA new methodology for yield optimization of integrated circuits is presented. We propose a dc external control scheme which performs on‐line estimation of the active device model parameters and proper correction of the bias point. Design of a 2.5 Gbit/s front‐end amplifier has been performed, and a strong yield improvement has been found. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 134–137, 2001.
Study of the experimental performance of AR‐based data‐extrapolation algorithms for high‐resolution radar imaging
Authors: Kim Kyung‐Tae , Bae Ji‐Hoon , Seo Dong‐Kyu , Kim Hyo‐Tae 
Published: August 2002

AbstractIn this letter, we compare the experimental performance of data‐extrapolation algorithms for high‐resolution radar imaging. The three methods considered in this paper are based on the autoregressive (AR) model, including the Burg method, the modified covariance method, and the modified covariance method, coupled with singular value decomposition. The performance of each algorithm in terms of extrapolation accuracy is compared using the radar cross‐section (RCS) data of an F117 model measured in the compact range facility. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 151–156, 2001.