bluuebunny/crossref_metadata_2025_split huggingface dataset:
An efficient method for analyzing graded‐index optical fibers
Authors: Guerreiro And M. V. Das Neves , Faria J. A. Brandao 
Published: July 2007

AbstractWe describe a method for analyzing graded index optical fibers using a stepwise function approximation to model the core refractive index profile. For each homogeneous shell uncoupled radial equations for the longitudinal field components Ez and Hz are considered. Relationship between field solutions corresponding to core adjacent shells is established with the help of appropriate boundary conditions. Numerical results obtained with this method are presented and discussed, with special attention being focused on the analysis of the number of discretization steps necessary for achieving satisfactory core modeling. © 1993 John Wiley & Sons, Inc.
Analysis of electromagnetically coupled patch antennas
Authors: Fan Zhibo , Lee Kai‐Fong 
Published: July 2007

AbstractA spectral domain full‐wave analysis is given for a class of electromagnetically coupled patch antennas with cylindrical geometries. Numerical results on the input impedances of the stacked circular disks and the ring‐loaded circular disk are in good agreement with published results in the literature. © 1993 John Wiley & Sons, Inc.
Comparison of multimode network and spectral domain analysis applied to metallic strips
Authors: Langley R. J. , El‐Sheikh A. N. A. 
Published: July 2007

AbstractThis Letter compares the results of two methods for predicting the scattering from periodic arrays of metallic strips. The first method is a full spectral domain analysis incorporating the sampling theorem, while the second is a multimodal network solution to the problem. Results are compared for thin and thick strips under both TE and TM wave incidence. It is shown that the multimode network solution is about five times more computationally efficient and yet yields virtually identical results. © 1993 John Wiley & Sons, Inc.
Local interconnection neural networks
Authors: Zhang Jiajun , Zhang Li , Yan Dapen , He Anzhi 
Published: July 2007

AbstractBased on the Hopfield model, a new concept of the local interconnection neural network (LINN) is proposed. Compared with the global interconnection neural network (GINN), LINN offers a smaller interconnection matrix. © 1993 John Wiley & Sons, Inc.
A dielectric hybrid‐mode horn as a gaussian beam‐mode antenna in 3‐MM band
Authors: Dou W. B. , Sun Z. L. 
Published: July 2007

AbstractA dielectric hybrid‐mode horn has been analyzed theoretically. The horn can support a balanced hybrid HE mode. The fields under the balanced hybrid condition have been expressed. By optimizing the structure parameters, the fraction of the power radiated into the fundamental Gaussian mode can reach about 98% over a wide frequency range in 3‐mm band. Drawbacks are the effects of dielectric losses. Thus the new horn represents an attractive alternative to the corrugated horn for forming the Gaussian beam in millimeter‐wave band. © 1993 John Wiley & Sons, Inc.
Optical pattern logic processing with one‐rule symbolic substitution
Authors: Liu Guoqlang Li Liren 
Published: July 2007

AbstractIn this article, one‐rule symbolic substitution is introduced to process 2D pattern logic. All the 16 possible logic gates of two input variables are designed. By using a combined system of a multiimaging unit and an optoelectronic morphological unit with two independent input planes of the control pattern and the input patterns, all the logic functions can be achieved by simply programming the control pattern. Experimental results are presented. © 1993 John Wiley & Sons, Inc.
Some focusing properties of chirped gratings at microwave frequencies
Authors: Christodoulou C. G. , Schmidt J. C. 
Published: July 2007

AbstractThis article presents a theoretical and experimental analysis of the focusing properties of metallic chirped gratings. These aperiodic gratings are designed to focus energy at a desired position by varying the strip width and strip spacing. The location of the individual strips, their width variation, distance of separation, and angle of incidence determine the focal point of the chirped grating. © 1993 John Wiley & Sons, Inc.
Free‐space techniques for biisotropic media parameter measurement
Authors: Tretyakov Sergei A. , Haliullin DamirY A. 
Published: July 2007

AbstractFour scalar complex parameters (dielectric permittivity, magnetic permeability, chirality parameter, and nonreciprocity parameter) characterize general biisotropic materials. In this communication, possible techniques for material parameter measurement are addressed. Procedures are based on free‐space measurements of plane‐wave reflection from the transmission through a biisotropic slab. Explicit formulas expressing the material parameters in terms of scattering matrix coefficients are given for measurements at normal incidence. © 1993 John Wiley & Sons, Inc.
Near‐field pattern diffracted by a spherical cavity in a denser medium
Authors: And Jin‐Seob Kang , Ra Jung‐Woong 
Published: July 2007

AbstractA copolarized electric field diffracted by a spherical cavity in a denser dielectric medium is analyzed in the forward near‐field region when the wavelength is comparable to one half the cavity radius. It is shown that double nulls and dips exist in the measurement plane transverse to the propagating direction of the incident field, and their dependences on the frequency, the distance of the measurement plane, and the measurement angles are analyzed. © 1993 John Wiley & Sons, Inc.
On the direct synthesis of high‐directivity tapered‐side‐lobe planar arrays with circular boundaries
Authors: Botha E. , McNamara D. A. 
Published: July 2007

AbstractIt is shown in this article how the generalized Villeneuve distribution can conveniently be used for the synthesis of high‐directivity low‐side‐lobe planar arrays with circular boundary shapes. © 1993 John Wiley & Sons, Inc.
Application of hadamard transform to fiber‐optic smart‐skin sensing
Authors: Yu Francis T. S. , Yin Shizhuo , Ruffin Paul B. 
Published: July 2007

AbstractAn array of optical fibers can be applied to smart‐skin sensing applications, which include stress monitoring, fatigue detection, temperature sensing, etc. Although a single light source can be used in a fiber array sensor, the input light power is divided by a sensing fiber array and each fiber may require a detector. Thus as the channel number of a fiber array increases, the number of detectors also increases and the signal intensity of each fiber channel decreases, which decreases the signal‐to‐noise ratio and increases the complexity and the cost of the system. In this article we will analyze the Hadamard transform to enhance the signal processing of the fiber array sensor. The apparent advantages are that only one detector is needed and the signal‐to‐noise ratio of the fiber array sensor can be improved by a factor of N/2, where N is the number of sensing fibers. Analysis for an array of 127 sensing fibers is illustrated, in which we have shown that the calculated results are in agreement with the analytical model. © 1993 John Wiley & Sons, Inc.
Design and realization of a low‐noise front end for a rdss mobile terminal
Authors: D'agostino Stefano , D'inzeo Guglielmo , Marietti Piero , Betti‐Berutto Andrea 
Published: July 2007

AbstractA low‐cost high‐gain front‐end amplifier has been developed at 2.5‐GHz frequency for use in RDSS (radio determination satellite services) mobile terminals. The RDSS system allows an accurate positioning with the possibility of serving a large user population using the spread‐spectrum modulation. Such an amplifier, built on 0.8‐mm PTFE board, provides a low noise figure, a 31‐dB gain and good input and output matching on the 16‐MHz bandwidth allocation. All the results have been obtained using low‐cost commercially available devices. © 1993 John Wiley & Sons, Inc.
A perturbation approach to the analysis of index ellipsoid deformations in biaxial and uniaxial media
Authors: Faria J. A. Brandao 
Published: July 2007

AbstractUnder the disturbing influence of photoelastic, piezoelectric, or electrooptic effects, anisotropic media have their natural behavior modified, the modification being described by a change in both the dimensions and orientation of the index ellipsoid. A first‐order perturbation method useful for determining the perturbed index ellipsoid based on the unperturbed one is developed. Results concerning the new principal axes and principal refractive indices of the perturbed optical medium are presented. © 1993 John Wiley & Sons, Inc.
AN ULTRA‐LOW‐NOISE MILLIMETER‐WAVE OSCILLATOR USING A SAPPHIRE DISK RESONATOR AND HIGH‐TEMPERATURE SUPERCONDUCTOR GROUND PLANES
Authors: Negrete George V. 
Published: July 2007

AbstractThe first fully integrated HTS millimeter‐wave oscillator operating at 77 K with a phase noise improvement of 20 dB over conventional oscillators is reported. A loaded Q of 59,000 at 36.5 GHz obtained from a sapphire resonator shielded by HTS ground planes is almost 100 times greater than ceramic resonators. © 1993 John Wiley & Sons, Inc.
Analysis of a millimeter‐wave integrated beam‐forming network for quasioptical multibeam antennas
Authors: Bankov Sergey E. , Bugrova Tatiana I. 
Published: July 2007

AbstractAn integrated beam‐forming network analysis for multibeam antennas based on an array of dielectric slotted waveguides in millimeter waves is proposed. The advantages of such networks include low losses, high aperture efficiencies, and design flexibility in comparison with traditional quasitopical systems. A new technique for obtaining the main characteristics by solving eigenwave and diffraction problems of the basic structure of the proposed network has been developed. © 1993 John Wiley & Sons, Inc.
Design and realization of a reduced‐size microstrip 3‐dB rat‐race hybrid coupler
Authors: Brewster B. D. , Robertson I. D. , Gemikonakli O. 
Published: July 2007

AbstractA reduced‐sized rat‐race coupler based on a meander line configuration, with bend equivalent phase length compensation, is presented. © 1993 John Wiley & Sons, Inc.
Polarization‐independent operation of reflective fiber ring resonators
Authors: Mouroulis Pantazis 
Published: July 2007

AbstractThe fringe shape stability of fiber ring resonators that incorporate an orthoconjugate reflector (OCR) is discussed. A resonator with a 90° polarization rotation and an OCR displays a stable fringe shape upon reflection, independent of the input polarization and of the loop birefringence. © 1993 John Wiley & Sons, Inc.
Axial propagation in general helicoidal bianisotropic media
Authors: Lakhtakia Akhlesh , Weiglhofer Werner S. 
Published: July 2007

AbstractHelicoidal bianisotropic materials (HBMs) are rotationally inhomogeneous in one spatial direction. A simple procedure to derive exact solutions for axial propagation of electromagnetic waves in general HBMs is presented here. © 1993 John Wiley & Sons, Inc.
Electromagnetic scattering by a strip grating with nonplanar illumination
Authors: Gimeno B. , Marquina J. L. , Navasquillo J. , Pomer F. 
Published: July 2007

AbstractAn angular‐spectrum method combined with the Galerkin procedure has been used to evaluate the electromagnetic scattering of a beam radiated by an aperture antenna after being incident obliquely upon a strip grating. Integral expressions for the transmitted and reflected fields are obtained. The incident beam radiated by the antenna is diffracted in several beams corresponding to the propagative Floquet harmonics. An angular shift of the transmitted and reflected fundamental harmonic beams has been shown. Comparison between numerical and experimental results validates this method. © 1993 John Wiley & Sons, Inc.
High‐sensitivity optical sampling using an erbium‐doped fiber laser strobe
Authors: Schlager J. B. , Hale P. D. , Franzen D. L. 
Published: July 2007

AbstractOptical pulses at a repetition frequency of 1 GHz from a gainswitched InGaAsP distributed‐feedback laser diode at 1.3 μm are optically sampled with compressed pulses from a mode‐locked erbium‐doped fiber laser amplifier. High signal‐to‐noise ratios down to 21‐μW average laser‐diode power with temporal resolutions close to the sampling pulse duration of 4 ps are achieved. The sampled waveform is displayed at a repetition rate of 3 Hz or higher to give a real‐time measurement.
Field singularities at the common tip of a number of concentric biisotropic cones
Authors: Olyslager Frank 
Published: July 2007

AbstractIn this contribution we present a general matrix formalism to determine the singular electromagnetic field behavior at the common tip of a number of concentric circular cones consisting of lossless biisotropic, perfect electric conducting or perfect magnetic conducting material. Three cases are studied in detail: a chiral salient and reentrant cone, two perfectly conducting cones, and a perfectly conducting cone balancing on a semiinfinite chiral space.
(FD)2‐TD and experimental comparison for a cylindrical cavity loaded with lossy dielectric
Authors: Hum P. J. , Leong M. S. , Kooi P. S. , Yeo T. S. 
Published: July 2007

AbstractIn this article, the frequency‐dependent finite‐difference time‐domain (FD)2‐TD technique is used to analyze a coaxial‐line excited cylindrical cavity loaded with an electrically lossy dielectric, modeled by a first‐order Debye expression. Results obtained for the reflected voltage in the coaxial line are Fourier transformed to yield the reflection coefficient Γ and input admittance at the coaxial aperture. Experimental measurements for Γ show good agreement with predicted (FD)2‐TD results.
Conductor‐backed and upper‐shielded coplanar waveguide with finite ground planes
Authors: Costamagna Eugenio , Fanni Alessandra 
Published: July 2007

AbstractA variational procedure is proposed to accurately analyze the electrical quasi‐TEM parameters of coplanar waveguides, taking into account finite‐extent as well as semiinfinite lateral ground planes. The procedure leads to accurate calculations and allows comparison with results already presented for coplanar waveguides. Data for geometries incompletely analyzed in the technical literature are provided.
The variation of short‐gate‐length gaas mesfet intrinsic noise parameters with BIAS
Authors: Greaves S. D. , Unwin R. T. 
Published: July 2007

AbstractThe use of intrinsic noise parameters P, R, and C to describe the noise mechanisms present in short‐gate‐length GaAs MESFETs is well established. These parameters are, however, bias dependent, and as yet no analytic solution is available that can accurately predict this dependency. Here results are presented that show the evolution of these parameters with drain current for three practical devices.
Single‐mode four‐port optical fiber loop resonators using a nonplanar 3 × 3 fiber coupler
Authors: Ja Y. H. , Dai X. 
Published: July 2007

AbstractThis article presents the first experimental observation of the output resonance response of two single‐mode four‐port optical fiber loop resonators using a nonplanar 3 × 3 fiber coupler with a triangular cross section. It is found that, under a special condition of coupling strength kd = 2π/9, the output resonance responses of these two different types of fiber loop resonators are the same, and also identical to that of a same type of fiber ring resonator. The loop resonators may be used as two‐channel wavelength‐division multi/demultiplexers and optical switches.
A stable electric field integral equation approach for analyzing scattering from nonplanar wire meshes with arbitrarily small cell sizes
Authors: Michielssen E. , Whites K. 
Published: July 2007

AbstractA simple and effective approach is presented for analyzing the plane‐wave scattering from nonplanar wire meshes. In contrast to both traditional integral equation solutions and homogenization techniques, which have a limited range of application in terms of the size of the unit cell, the present technique is applicable to structures with periodicities varying from a small fraction of the wavelength (e.g., 10−10λ0) up to several wavelengths. The technique is applied to the analysis of meshes consisting of straight wires as well as wire meshes containing helical elements.
Experimental reduction of phase‐noise influence for an optical CPFSK system with I.F. filtering
Authors: Jaouën Y. , Roudas I. , Gallion P. 
Published: July 2007

AbstractTheoretical modeling and experimental analysis of the influence of i.f. filtering on performance of optical heterodyne CPFSK systems with differential detection in the presence of phase noise are compared. It is shown that for a bit rate of 1 Gbits/s with a modulation index of 1, i.f. filtering reduces phase noise influence, leading to a significant reduction of the bit‐error‐rate floor.
Cross‐polarization characteristics of rectangular microstrip patch antennas on a cylindrical surface
Authors: Ke Shyh‐Yeong , Wong Kin‐Lu 
Published: July 2007

AbstractThe cross‐polarization characteristics of a rectangular microstrip patch antenna mounted on a cylindrical surface are investigated by using the modal‐expansion theory. The case of the patch antenna excited at TM01 mode is treated. Numerical results showing the variations of the cross‐polarization level for various aspect ratios and different curvature radii are given. A great dependence of the cross‐polarization level on the curvature radius of the cylindrical microstrip patch antenna is observed. The effects of feed positions on the cross‐polarization characteristics are also analyzed.
Influence of chirality parameter on the propagation characteristics of elliptical chirowaveguide
Authors: Cheng Dajun 
Published: July 2007

AbstractThe boundary value problem of an elliptical chirowaveguide is rigorously formulated by constructing the elliptical cylinder vector wave functions. Influence of chirality parameter both on the propagation axial constant and on the attenuation constant, are illustrated for the first several modes. © 1994 John Wiley & Sons, Inc.
Transient analysis of conducting half‐plane problem with noncausal scattering image
Authors: Nikoskinen K. I. , Lindell I. V. , Ermutlu M. E. 
Published: July 2007

AbstractIn the present article two‐dimensional transient scattering from a perfectly conducting half plane is studied. The excitation is an infinite impulsive line current parallel to edge of the conductor. Due to the symmetry of the problem the electromagnetic field everywhere is TM along the direction defined by the edge. The analysis presented in this article is based on a new time‐harmonic image solution found for the scattered field. The frequency‐domain image current giving the reflected and diffracted fields is an exact function that can be expressed in terms of simple trigonometric functions. It is dependent only on the coordinates and the amplitude of the source, but interestingly, it is independent of the used frequency. Thus, the corresponding time‐domain image is independent of time, which makes it noncausal. However, when integrating this image to compute the actual field, physical and causal results are obtained. © 1994 John Wiley & Sons, Inc.
Corrugated pyramidal horns with improved E‐plane radiation patterns
Authors: Narasimhan M. S. , Jayakumar Immanuel 
Published: July 2007

AbstractThe design and experimental studies on a pyramidal horn with corrugations and choke on the outer surface of the E‐plane walls excited in the TE10 mode with improved far‐field E‐plane patterns are reported in this Letter. © 1994 John Wiley & Sons, Inc.
Microstrip antenna with polarization switching
Authors: Dauguet Stéphane , Ongareau Eric , Wyrwinski Jacques 
Published: July 2007

AbstractIn this article the principle of an elementary printed antenna connected with an active hybrid coupler able to provide right‐ or left‐hand circular polarization is investigated. Dual‐gate MESFETs are used as phase shifters, and polarization switching is obtained by changing dc voltage applied to the control gate of each MESFET. Equal‐amplitude signals with identical phases can also be provided to generate linear polarization. Design and performance of a square patch with such polarization switching capability in S band is presented. © 1994 John Wiley & Sons, Inc.
Use of microstrip antenna technology in an angle diversity receiver for a 15‐GHz radio link
Authors: Tessereau S. , Zein G. El , Citerne J. 
Published: July 2007

AbstractThis Letter describes how the performance of a line‐of‐sight radio link can be improved by using an angular diversity receiver. The received antenna is a dual‐beam microstrip antenna realized with two linear arrays of 20 transverse printed dipoles, series fed by proximity coupling to a microstrip line. © 1994 John Wiley & Sons, Inc.
On the crucial role of impedance matching in chirolens design
Authors: Lakhtakla Akhiesh 
Published: July 2007

AbstractIt is shown that impedance matching delivers two specific benefits for chirolens design. First, there is no left‐handed ↔ right‐handed field conversion inside a nonhomogeneous chirolens with a spatially constant impedance. Second, when the chirolens is impedance matched to the surrounding free space, the incident, the scattered and the internally induced fields have the same handedness. In addition, the backscattered field of an impedance‐matched, radially non‐homogeneous, spherical chirolens is null in the far zone. © 1994 John Wiley & Sons, Inc.
Strain effects on refractive index and confinement factor of InxGa(1−x)As laser diodes
Authors: Ghafouri‐Shiraz H. , Tsuji S. 
Published: July 2007

AbstractThe effects of strain upon the bandgap energy, the refractive index, and the confinement factor of a SCH laser diode with InxGa(1−x)As as its active layer have been investigated. © 1994 John Wiley & Sons, Inc.
Scattering from an internal penetrable inhomogeneity of a dielectric slab waveguide
Authors: Yarovoy Alexander G. 
Published: July 2007

AbstractA rigorous analysis of two‐dimensional scattering of a dielectric slab eigenmode from a penetrable cylinder is carried out by an integral equation method. A new procedure for reduction of an initial integral equation system to a well‐conditioned matrix equation is developed. Numerical results are presented for cylinders with different cross‐section shapes. A physical explanation of the revealed effects is proposed. © 1994 John Wiley & Sons, Inc.
Spectral‐domain decoupling method of electromagnetic waves propagating and radiating in bianisotropic gyroelectromagnetic chiral media
Authors: Wenyan Yin , Pao Li , Wei Wan 
Published: July 2007

AbstractIn this article a spectral‐domain decoupling method of electromagnetic waves propagating and radiating of sources in bianisotropic gyroelectromagnetic chiral media is presented, and the general transmission‐line‐like equations for the description of field quantities (IE‐, VE, VM, IM) are obtained using the technique of matrix transformation, which has been developed by Tsalamengas. As a practical application, the propagation behavior of electromagnetic waves in multilayered bianisotropic gyroelectromagnetic parallel‐plate chirowaveguides is investigated, and it is shown that in such a nonreciprocal chirowaveguide, propagating modes are always hybrid (EH and HE). Especially, the dyadic Green's function of sources in a grounded bianisotropic gyroelectromagnetic chiral superstrate‐substrate structure is derived, and it can be directly used to analyze the radiation characteristics of gyroelectromagnetic chirostrip antennas. © 1994 John Wiley & Sons, Inc.
Analysis of spherical annularring microstrip structures with an air gap
Authors: Chen Horng‐Dean , Wong Kin‐Lu 
Published: July 2007

AbstractThe spherical annular‐ring microstrip structure with an air gap is studied rigorously by using a full‐wave analysis and a momentmethod calculation. This study includes the analysis of the resonant frequencies and bandwidths of the microstrip structure for antenna applications. Results show that the bandwidth increases due to the existence of an air gap. This increase in bandwidth is also found to be more significant for the annular‐ring patch with smaller inner radius. © 1994 John Wiley & Sons, Inc.