bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of crossing interconnections on signal propagation on the GaAs‐based integrated circuits
Authors: Goel A. K. , Prabhakaran P. J. 
Published: July 2007

AbstractWe have analyzed the effects of embedded crossing interconnections on signal propagation in the top‐level driven interconnection on GaAs‐based integrated circuits. The algorithm has been used to study the dependences of the cross talk and propagation delays on the various crossing interconnection parameters. Results can be utilized for optimization of the high‐speed circuits. © 1993 John Wiley & Sons, Inc.
High‐power, low‐loss, broadband, spdt switch for VHF applications
Authors: Agarwal Arvind 
Published: July 2007

AbstractThis Letter discusses the design and development of high power, low‐loss SPDT switch using SPDT vacuum relays from dc to VHF range. One unit of SPDT switch was developed and subjected to 120.0‐KW peak power at 53 MHz with no trace of breakdown. © 1993 John Wiley & Sons, Inc.
The effect of dielectric truncation on the radiation of a microstrip ring antenna operated at higher‐order modes
Authors: Iyer S. M. Vaitheeswaran , Karekar R. N. 
Published: July 2007

AbstractSurface wave effects on the radiation of microstrip ring antennas are studied theoretically using the full‐wave solution based on reflection matrices for a microstrip ring antenna when they are operated at higher‐order modes. The effects on the radiation due to changes in the radius of the truncated dielectric substrate, the thickness, and the permittivity are examined. A choice between TM11 at ϵr = 9.8 or TM12 at ϵr = 2.2 is suggested. © 1993 John Wiley & Sons, Inc.
On the design and analysis of ultrabroadband antenna windows
Authors: Prasad R. V. Hara , Lakshminarayana D. 
Published: July 2007

AbstractThe design, analysis, and the results obtained on two ultrabroad‐band antenna windows, operating over 2‐18 GHz, one in A‐sandwich and the other in C‐sandwich construction are presented. Curves are given for theoretical and practical power transmission coefficients. The maximum transmission loss measured in the A‐sandwich window is <1.5 dB and that of the C‐sandwich window is <1.5 dB over the complete band. © 1993 John Wiley & Sons, Inc.
Evolution of signals in long‐haul fiber links
Authors: Matera F. , Mecozzi A. , Romagnoli M. , Settembre M. 
Published: July 2007

AbstractPropagation of nonsoliton and soliton signals in long‐haul fiber links is numerically investigated in the presence of chromatic dispersion, the Kerr effect, and noise of erbium amplifiers. Conditions for propagation of a nonsoliton signal with good system performances are found when an anomalous dispersion region is used. A comparison with systems based on such signals and soliton systems are also presented. © 1993 John Wiley & Sons, Inc.
A millimeter‐wave total power radiometer
Authors: Lyons B. N. , Vizard D. R. , Pike J. P. , Kelly W. M. 
Published: July 2007

AbstractThe design of a multichannel millimeter‐wave total power radiometer with frequent calibration is described. The radiometer has seven channels ranging in frequency from 20 to 183 GHz. The radiometer combines a quasioptical front end with subharmonic mixers and integrated calibration loads to yield a compact low‐cost radiometer package. Measured results are presented. © 1993 John Wiley & Sons, Inc.
The analysis of propagation characteristics in planar gyrotropic chirowaveguides
Authors: Wenyan Yin , Pao Li 
Published: July 2007

AbstractWe analyze the coupled‐mode propagation in planar gyrotropic chirowaveguides. At first, the transverse components of electric and magnetic fields in such waveguides are expressed in terms of the longitudinal components of Ē and H̄. Dispersion diagrams for the parallel metallic‐plate gyrotropic chirowaveguides are shown, and their novel features are pointed out. The effects of chirality admittances on the cutoff wavelengths of propagating modes in the grounded planar and parallel metallic‐plate gyrotropic chirowaveguides are taken into consideration. © 1993 John Wiley & Sons, Inc.
Performance evaluation of moment‐method codes on an intel iPSC/860 hypercube computer
Authors: Klimkowski Kenneth , Ling Hao 
Published: July 2007

AbstractThe performance of a moment‐method code on a parallel computer is analyzed and evaluated. Algorithmic complexity costs are discussed in terms of matrix size and a parameter of matrix partitioning, subblock size. The measured computational times of the matrix fill operation and LU solver are analyzed in terms of scaled efficiencies. © 1993 John Wiley & Sons, Inc.
A spectral‐domain‐eigenfunction method for radiation by a cavity‐backed planar structure
Authors: Ronghong Jin , Yuanheng Qiu 
Published: July 2007

AbstractA planar structure backed with a cavity is analyzed by a spectral‐domain‐eigenfunction method. An appropriate basis function and an appropriate weighting function have been chosen, which greatly simplifies the process of the solution. Finally, the calculated radiation fields of the antenna are compared with the measured results. © 1993 John Wiley & Sons, Inc.
Eigenwaves in uniaxial chiral omega media
Authors: Tretyakov Sergei A. , Sochava Alexander A. 
Published: July 2007

AbstractEigenwaves in novel materials which have properties of chiral composites and omega structures are considered. The materials can be modeled by uniaxial bianisotropic constitutive relations. Both chiral and omega composites possess promising features, for and one may expect still more interesting effects in more general media. © 1993 John Wiley & Sons, Inc.
Input impedance of rectangular microstrip antennas for different feed sizes
Authors: Dan S. , Chauhan B. , Maggo G. , Bhattacharya A. , Thakur A. , Bhattacharjee A. K. 
Published: July 2007

AbstractClosed‐form expressions for the input impedance of half‐wavelength rectangular microstrip antennas fed by coaxial connectors of different sizes at the center of one of the radiating edges and open circuited at one of the ends are derived. Good agreement between computed and measured data is obtained. © 1993 John Wiley & Sons, Inc.
Design analysis and fabrication of lumped‐distributed branch‐line couplers for coplanar waveguide mmics
Authors: Gillick M. , Robertson I. D. , Joshi J. S. 
Published: July 2007

AbstractAn analysis of lumped‐distributed coplanar waveguide (CPW) branch‐line couplers suitable for GaAs MMIC designs is presented. This investigation takes into account the degree of coupling, impedance transformation, and levels of miniaturization in order to provide a greater design flexibility for integration with uniplanar monolithic circuits. Synthesis techniques and design graphs are given for these couplers and a monolithic 50‐15‐OM version has been fabricated and tested. The coupler's measured results show an amplitude balance of 4.7 × 0.3 dB, input and output return losses of better than 12 and 15 dB, respectively, and an isolation of better than 20 dB over the range 14–16 GHz. This new method of designing miniaturized couplers demonstrates their suitability for balanced amplifiers, especially when they are incorporated into CPW MMICs. © 1993 John Wiley & Sons, Inc.
Measurement of the current‐density distribution in high‐temperature superconducting microstrip by means of kinetic‐inductance photoresponse (invited paper)
Authors: Newman Harvey S. , Culbertson James C. 
Published: July 2007

AbstractWe report a technique for measuring the spatial profile of microwave‐frequency currents in resonant thin‐film superconducting microstrip devices operated near resonance. We probe the patterned superconducting device as a function of position by scanning a modulated light beam across the region to be probed. With the light focused to a spot size much smaller than the microstrip width, we have measured the current density distribution as a function of position across the width of the strip. Using an elementary model for the superconducting current density distribution, we fit an effective penetration depth at the edge of the microstrip. © 1993 John Wiley & Sons, Inc.
Demonstration of A 3‐GHz‐bandwidth real‐time spectral‐analysis receiver based on a high‐Tc superconductive chirp filter (invited paper)
Authors: Lyons W. G. , Seaver M. M. , Arsenault D. R. , Boisvert R. R. , Sollner T. C. L. G. 
Published: July 2007

AbstractA 3‐GHz‐bandwidth real‐time spectral‐analysis receiver has been demonstrated. The fully integrated compressive receiver is based on the chirp‐transform algorithm and uses a high‐Tc superconductive (HTS) tapped‐delay‐line chirp filter with a time‐bandwidth product of 40. The 3‐GHz bandwidth of the HTS chirp filter is unobtainable using other technologies such as surface acoustic waves. This prototype receiver, a combination of an HTS passive microwave component and conventional semiconductor circuits, demonstrates a microwave system that could not be built without the unique HTS component. © 1993 John Wiley & Sons, Inc.
Superconducting multiport antenna arrays (invited paper)
Authors: Chaloupka H. 
Published: July 2007

AbstractApplications of HTS to radiating elements and beam‐forming networks of multibeam and/or multifrequency arrays are discussed. This includes radiating elements which meet special requirements with respect to size and frequency response. Realized versions of both a three‐port HTS array and a April × 4 Butler matrix are presented. © 1993 John Wiley & Sons, Inc.
Wide hts microbridge series array transmission line
Authors: Jackson Charles M. , Kobayashi June H. , Wire M. S. , Heflinger Lee O. , Lee Alfred , Pettiette‐Hall Claire , Hu Roger , Burch John F. 
Published: July 2007

AbstractExperiments are performed on an HTS transmission line fabricated with a series array of Josephson junctions. We have determined the phase shift mechanism and have measured the magnitude of the phase shift of wide junctions. A qualitative model of the phase shift mechanism has been developed which explains the effects of applied magnetic fields. © 1993 John Wiley & Sons, Inc.
Double serial amplified recirculating delay line
Authors: Vizoso B. , Civera R. , López‐Amo M. 
Published: July 2007

AbstractTheoretical results on a double serial amplified recirculating delay line are presented. Its application as filter is emphasized, showing a wide flexibility of design by appropriate choices of its main parameters: loop length, gain, and coupling ratio of the couplers. © 1993 John Wiley & Sons, Inc.
The scan performance of the fresnel‐zone plate antenna: A comparison with the parabolic reflector antenna
Authors: Baggen L. C. J. , Jeronimus C. J. J. , Herben M. H. A. J. 
Published: July 2007

AbstractUsing Kirchhoffs diffraction theory, scalar field analyses of two off‐axis focused antenna systems, the Fresnel‐zone plate antenna (FZPA) and parabolic reflector antenna, are presented. Expressions which describe the gain patterns of both antennas are derived and used to examine the scan properties of the two systems and to reveal and discuss similarities and differences between them. The results of the analysis give good insight into future applications of the FZPA as a multibeam antenna. © 1993 John Wiley & Sons, Inc.
Optical‐fiber multiple PPM frame synchronization
Authors: Elmirghani Jaafar M. H. , Cryan Robert A. , Clayton F. M. 
Published: July 2007

AbstractAt high data rates and gigabit schemes, orthogonal optical‐fiber pulse position modulation (PPM) prematurely exhausts the available pulse width resources. Multiple PPM (MPPM) offers improved throughput while preserving the PPM sensitivity attraction. The multiple pulse positions per pulse width place a high demand on the synchronization subsystem. We propose MPPM for the optical fiber channel, then investigate the synchronization requirements at the chip, symbol, and frame rates. An original spectral characterization is presented for the format, illustrating that symbol and chip synchronization are achievable from the data stream. Frame synchronization is examined and a novel technique based on natural sequences is proposed and demonstrated, resulting in the extraction of both the frame frequency and the frame phase. Data pattern dependency is eliminated through an original technique, and a practical implementation is given. Practical results are presented for the synchronizers and shown to correlate with the developed models. © 1993 John Wiley & Sons, Inc.
New design techniques for high‐order narrow‐band microwave filters derived from low‐frequency recursive concepts
Authors: Billonnet L. , Jarry B. , Guillon P. 
Published: July 2007

AbstractWe show how high‐order narrow‐band microwave filters can be built with the help of various unitary first‐order recursive cells in strict accordance to low‐frequency principles. We illustrate our approach with the simulated results for a third‐order filter in the 2.25–8.4‐GHz frequency range. © 1993 John Wiley & Sons, Inc.
Effects of initial chirp of control pulse on soliton‐dragging logic gates
Authors: Tang Xiongyan , Ye Peida 
Published: July 2007

AbstractThe effects of the initial chirp of the control soliton pulse on the time shift of the soliton‐dragging logic gate (SDLG) is investigated numerically in this article. We find that the positive initial chirp increases the time shift and the negative initial chirp decreases the time shift. The physical interpretation for this phenomenon is presented. © 1993 John Wiley & Sons, Inc.
An S‐shaped optical fiber loop resonator using a 3 × 3 nonplanar fiber coupler
Authors: Ja Y. H. , Dai X. 
Published: July 2007

AbstractThe first demonstration of a new S‐shaped single‐mode fiber loop resonator is presented. The S‐shaped fiber loop resonator is made with a nonplanar 3 × 3 fiber directional coupler and two fiber delay lines. Expressions for the circulating (resonant) fields and the transmitted and reflected output fields are derived. Theoretical and experimental results show that this fiber loop resonator may have potential applications as a spectral filter and a closely spaced two‐channel wavelength division multi/demultiplexer.
Monolithic Ka‐band coplanar waveguide amplifier design in MMIC
Authors: Bayar Esen , Robertson Ian D. , Aghvami A. Hamid 
Published: July 2007

AbstractIn this article an effective design approach which realizes high‐frequency MMIC networks in grounded coplanar waveguide (CPWG) transmission media is demonstrated. Topological features which effect electrical characteristics are highlighted and a layout topology which minimizes secondary circuit parameters is illustrated. A method is described which enables these features to be implemented while minimizing discontinuity effects, and a practical application is demonstrated with a 23‐GHz CPWG amplifier design.
Low cost L‐band mobile terminal antennas for helicopters
Authors: Wu Te‐Kao 
Published: July 2007

AbstractThe feasibility of using a low‐gain antenna (LGA) as a mobile terminal antenna for helicopers is described in this article. The objectives are (a) to select the lowest cost antenna system which can be easily mounted on a helicopter and capable of communicating with a satellite, and (b) to determine the best antenna position on the helicopter to mitigate the signal blockage due to rotor blades and the multipath effect from the ehlicopter's body. The omnidirectional low gain antenna (LGA) is selected because it is simple, reliable, and low cost. The helix antenna is selected among the many LGAs because it is the most economical and has the widest elevation beam‐width. Both two‐ and four‐arm helices are studied experimentally to determine the antenna's performance and the scattering effects from the helicopter's body. It is found that the LGA should be located near the tail section and at least 8 in. above the helicopter.
Resonance in a spherical annular‐ring microstrip structure
Authors: Wong Kin‐Lu , Chen Horng‐Dean 
Published: July 2007

AbstractThe resonance problem of a spherical annular‐ring microstrip structure is investigated rigorously by using a Green's function formulation in the spectral domain. Numerical results of the complex resonant frequencies are obtained by using Galerkin's moment method. The convergence of the numerical calculation using different numbers of basis functions is also discussed. Typical numerical results of the resonant frequency and the quality factor, obtained from the real and imaginary parts of complex resonant frequency, for the microstrip structure used as a resonator element at TM11 mode and as an efficient radiator at TM12 mode are presented. Effects of the curvature on the resonant frequency and the quality factor of the structure are also analyzed and discussed.
Integrated active slot dipole antenna amplifier
Authors: Wu Xiao‐Dong , Chang Kai 
Published: July 2007

AbstractThis article presents the design and performance of a slop dipole antenna integrated directly with an FET amplifier. The measured radiation patterns of the antenna are linear with cross‐polarization levels of 11 dB down in E plane and 17.5 dB down in H plane. The measured gain of the antenna is 10 dB at 7.1 GHz. Compared with a passive antenna, the active antenna has an extra gain of 7 dB.
Single and double square‐loop frequency‐selective surfaces with thick metallization
Authors: Webb David B. , Michielssen Eric , Mittra Raj 
Published: July 2007

AbstractSingle and double square‐loop frequency‐selective surfaces (FSSs) are investigated to determine the effects of metallization thickness on the scattering characteristics. Results presented are computed via a spatial‐domain method of moments technique using triangular patch basis functions. To isolate the effects of metallization thickness, freestanding screens of infinite extent are considered.
Conformal absorbing boundary conditions for the vector wave equation
Authors: Chatterjee A. , Volakis J. L. 
Published: July 2007

AbstractAn absorbing boundary condition of second order is derived for mesh terminations conformal to the shape of the radiator or scatterer. The boundary condition is expressed entirely in terms of the principal curvatures of the termination surface and results in a symmetric system of equations when incorporated into the finite‐element functional.
New types of TEM cells with shaped inner and outer conductors
Authors: Costamagna Eugenio , Fanni Alessandra 
Published: July 2007

AbstractNumerical algorithms are utilized to design nontraditional transversal sections of TEM cells, leading to large areas of almost uniform electric field within small dimensions. Numerical inversion of the Schwarz‐Christoffel formula and predictor‐corrector mapping of equipotential lines are, utilized. © 1994 John Wiley & Sons, Inc.
Analytic solutions for the finite‐difference time‐domain and transmission‐line‐matrix methods
Authors: Chen Zhizhang , Silvester Peter P. 
Published: July 2007

AbstractEigenmodal decomposition formulations are given for numerical solutions of the finite‐difference time‐domain (FDTD) and the transmission‐line‐matrix (TLM) methods. Instead of direct simulation with these time‐recursive schemes, the analysis involves two steps: (1) solving an eigenvalue problem, and (2) analytically constructing the numerical solutions in terms of the eigenvalues and eigenvectors. The numerical solution at any time step can be obtained with only O(N) computation once the corresponding eigenvalue problem has been solved. The main advantage of this technique is that the eigenvalues and eigenvectors for a problem can be stored, the numerical solutions then quickly processed with the stored data. In addition, high‐frequency numerical noise can be reduced simply by discarding the related high‐frequency modes. © 1994 John Wiley & Sons, Inc.
Time‐domain modeling of the impedance boundary condition for an oblique incident parallel‐polarization plane wave
Authors: Wang Bing‐Zhong , Xiao Qun 
Published: July 2007

AbstractIn this article, the time‐domain impedance boundary condition (TDIBC) used for a thin layer coating over perfect conductors is obtained for the case of an oblique incident parallel‐polarization plane wave. Discretization of the TDIBC to efficiently handle the thin‐layer coating is presented in the context of the time‐domain finite‐difference (TDFD) technique. The TDFD solutions using our TDIBC are in good agreement with the analytical results. © 1994 John Wiley & Sons, Inc.
Microwave imaging in angular spectral domain based on the improved Newton's procedure
Authors: Park Cheon‐Seok , Park Seon‐Kyu , Ra Jung‐Woong 
Published: July 2007

AbstractAn iterative inversion in angular spectral domain based on the quasi Newton's procedure is presented. Angular spectral‐domain reconstruction is shown to be more insensitive to the noise in the scattered field than configuration domain reconstruction. It is also shown by closed‐form solution of a homogeneous circular cylinder that the local minima hindering this inversion process exist in the cost function. © 1994 John Wiley & Sons, Inc.
Analysis of a broadband hemispherical dielectric resonator antenna with a dielectric coating
Authors: Wong Kln‐Lu , Chen Nan‐Cheng 
Published: July 2007

AbstractA probe‐fed hemispherical dielectric resonator antenna with a dielectric coating is investigated rigorously by using a Green's function formulation. Numerical results for the input impedance at TE111 mode are calculated. It is found that, by coating the dielectric resonator antenna with a dielectric material having a relative permittivity about half that of the dielectric resonator antenna, the impedance bandwidth of the antenna can be significantly improved. This dielectric coating here serves as a transition region between the wave inside the dielectric resonator antenna and the free‐space wave, and thus can increase the impedance bandwidth of the antenna. A broadband dielectric resonator antenna can thus be obtained. © 1994 John Wiley & Sons, Inc.
MOCVD growth and ultrafast photoluminescence in GaAs and InAs freestanding quantum whiskers—a review
Authors: Viswanath A. Kasi , Hiruma K. , Yazawa M. , Ogawa K. , Katsuyama T. 
Published: July 2007

AbstractNanometer‐size quantum whiskers of InAs and GaAs have been fabricated by low‐pressure MOCVD. Time‐integrated and time‐resolved photoluminescence of GaAs wires of diameters 200, 100, 70, and 50 nm have been studied. The temperature dependence of PL peak energy was found to follow the same variation as the bandgap of GaAs, and Varshni's theory has been used to explain the temperature dependence. The main channel of radiative recombination was found to be due to free excitons. The nonuniformity in diameter and lattice phonon interactions were considered to understand the origin of the linewidth. From the time‐resolved PL the surface recombination lifetimes were measured directly. Surface recombination velocities were evaluated and were correlated to wire diameter. The quantum‐size‐dependent spatial part of the electronic wave function was thought to be responsible for the variation of surface recombination velocity with diameter. Surface treatment with sulphur reduced the surface depletion layer, as evidenced from the time‐resolved and time‐integrated spectra. The carrier lifetime was in picosecond time scales at 7 K and increased with temperature, thus confirming the quantum confinement effects. The polarization experiments revealed the one‐dimensional nature of quantum whiskers. © 1994 John Wiley & Sons, Inc.
Theoretical calculation of optical gain and threshold current density in strained in1−XGaxAs/InP quantum‐well lasers using strain‐dependent conduction‐band and valence‐band structures (invited paper)
Authors: Sugawara Mitsuru , Yamazaki Susumu 
Published: July 2007

AbstractWe theoretically calculate the optical gain of In1−xGaxAs/InGaAsP strained quantum wells on (001) InP substrates based on strain‐dependent conduction‐band and valence‐band structures. Using the calculated gain, we estimate threshold current density of the strained quantum‐well lasers. We show that both biaxial compressive and tensile strains can lower the threshold current density by ½–⅓, and clarijv the mechanism for the reduction. © 1994 John Wiley & Sons. Inc.