bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐efficiency InGaAs/InGaAsP compressively strained multiple‐quantum‐well laser diode
Authors: Ogita Shouichi , Kobayashi Hirohiko , Higashi Toshio , Okazaki Niro , Aoki Osamu , Soda Haruhisa 
Published: July 2007

AbstractThe characteristics of the InGaAs/InGaAsP compressively strained multiple‐quantum‐well laser diodes with thin wells were studied experimentally to realize the pumping laser diode for the optical‐fiber amplifier. High external quantum efficiency and comparatively low threshold current density were obtained when the thickness of the well was reduced to less than 2 nm. It was also found that the characteristic temperature depends only on the optical confinement to the wells when the optical confinement factor is smaller than 1.5%. Output power as high as 210 mW was demonstrated in the coated sample with the optimized well structure. © 1994 John Wiley & Sons, Inc.
Extremely low power penalty in 2.5‐Gb/S transmission experiment using 1.55‐μm MQW‐DFB lasers with optimized QW number
Authors: Kawano M. , Aoyagi T. , Watanabe H. , Takiguchi T. , Nakajima Y. , Takemoto A. , Hirano R. 
Published: July 2007

AbstractFor 1.55‐μm MQW‐DFB lasers, the dependence of transmission characteristics under 2.5‐Gb/s modulation on the number of wells is investigated experimentally and theoretically. The fiber length is 70 km and the total dispersion is 1470 ps/nm. Extremely low power penalty of 1.3 dB is obtained for a 12‐well laser with large differential gain of 7.1 × 10−16 cm2. © 1994 John Wiley & Sons, Inc.
Application of the 2D finiteelement/boundary‐element method to scattering from coated aerofoils
Authors: Meyer F. J. C. , Davidson D. B. 
Published: July 2007

AbstractA two‐dimensional solver combining the finite‐element method (FEM) with the boundary‐element method (BEM) has been implemented and results have previously been compared to analytical solutions using canonical problems. The code has now been applied to predict scattering from electromagnetically larger, inhomogeneous, and lossy objects of more complex shape, including a coated aerofoil, and the results are compared to analytical as well as experimental data. The cross sections modeled were up to 15 wavelengths in Size. © 1994 John Wiley & Sons, Inc.
A C‐band microstrip varactor‐tuned reflection phase shifter employing UHF general‐purpose diodes
Authors: Brewster B. D. , Robertson I. D. 
Published: July 2007

AbstractA 4‐GHz phase shifter based on a hybrid coupler terminated with reverse‐biased UHF general‐purpose diodes is shown capable of providing excellent tuning responses, adequate for noncritical applications. The assembly demonstrates that considerable component specijcation relaxation can be implemented for low microwave frequencies. © I994 John Wiley & Sons, Inc.
A model for timing jitter estimation in optical‐fiber PPM
Authors: Elmirghanl Jaafar M. H. , Cryan Robert A. , Clayton F. M. 
Published: July 2007

AbstractAn original model for timing jitter estimation in optical‐fiber PPM is developed and used to examine the performance impairment due to imperfect slot synchronization. An original expression that predicts the spectral properties in the presence of jitter is presented. The extracted slot clock timing variance is evaluated in terms of the PPM parameters such as the number of slots and the modulation index, and the effects of the other parameters such as the phase‐locked loop (PLL) bandwidth and the fiber bandwidth are examined and used to optimize the slot clock timing variance. Original results are presented for the system wrong slot error (WSE) probability due to imperfect synchronization. The results indicate that this probability can be maintained well below the 10−9system operating error rate. The model enables the identification of the set of optimum PPM, PLL, and fiber parameters for a given required performance. © 1994 John Wiley & Sons, Inc.
Signal splitting using the traveling‐wave principle
Authors: Desclos Laurent , Floc'h Jean Marie , Bernick Philip 
Published: July 2007

AbstractIn this article we will describe a concept that we call active splitting. It is based on an extension of an existing structure. The primary advantages to active splitting are that it provides large frequency bandwidth and cascadability. Additionally, active splitting produces gain rather than loss. This feature allows us to design cells with multiple (more than two) in‐phase outputs and to adjust gain by using bias points on the same coplanar structure. © 1994 John Wiley & Sons, Inc.
On the simplified expression of realistic raindrop shapes
Authors: Li L. W. , Kooi P. S. , Leong M. S. , Yeo T. S. 
Published: July 2007

AbstractThe Pruppacher‐and‐Pitter (PP) raindrop model has been well accepted as a realistically distorted raindrop model. To employ this model for the investigation of radio wave attenuation by rain requires tedious numerical calculations. In this Letter a simple mathematical formula is used to simplify and improve the expression of the nonaxisymmetric distorted raindrop shapes, enabling the scattered field by rain to be derived analytically. The coefficients in the formula are determined for different raindrop sizes by translating the polar coordinates vertically and fitting the shapes of the Pruppacher‐and‐Pitter‐form raindrops to the shapes discussed in this Letter. Using the least‐squares method, a general expression for the coefficients in terms of the raindrop sizes is obtained. A comparison of the raindrop shapes obtained from the Pruppacher and Fitter expression and the expression in this Letter demonstrates the validity of the simplified formula for realistically distorted raindrops. © 1994 John Wiley & Sons, Inc.
On stability in the MMIC distributed amplifier
Authors: D'Agostino Stefano , Paoloni Claudio 
Published: July 2007

AbstractA study aimed at avoiding the high‐frequency oscillation phenomenon in the MMIC distributed amplifier is presented. The results obtained are applicable to both the design simulation step and the bias tuning phase on the realized amplifier. The analysis of a five‐section MMIC distributed amplifier confirms the validity of this research. © 1994 John Wiley & Sons, Inc.
Fiber ring resonator with fringe shape stabilization
Authors: Mouroulis Pantazis , Narayanan S. Anantha 
Published: July 2007

AbstractWe describe a fringe shape stabilization scheme for a birefringent fiber ring resonator with power exchange between the birefringent axes. It is shown that this type of resonator provides an easy way of deriving an error signal in order to stabilize the fringe shape. The system uses piezoelectric control of the fiber birefringence along a short portion of the loop, which counteracts environmentally induced changes in the fringe shape. The system is suitable for use in sensing and spectrum analysis applications requiring high accuracy and scale factor stability. © 1994 John Wiley & Sons, Inc.
Cavity stabilized Gunn oscillator at 35 GHz
Authors: Nag B. R. , Saha P. K. , Ghosh G. , Biswas S. K. 
Published: July 2007

AbstractThe performance characteristics of a 35‐GHz cavity stabilized Gunn diode oscillator is presented. The frequency variations are found to be reduced by a factor of 66 when the oscillator is locked to the cavity. © 1994 John Wiley & Sons, Inc.
A gamma distribution of raindrop sizes and its application to Singapore's tropical environment
Authors: Li L. W. , Kooi P. S. , Leong M. S. , Yeo T. S. 
Published: July 2007

AbstractThe use of a gamma distribution of raindrop sizes in the calculation of microwave rain attenuation is gaining acceptance. A method of calculating the general gamma distribution of raindrop sizes based on the rain attenuation relation aRb has been developed in this article using the measured microwave attenuation data with respect to the rain rates. The method, which has been tested using the CCIR model, overcomes the common problems of instability and does not suffer from the possibility of multiple solutions. The parameters of the gamma distribution suitable for the moderate climatic region are computed from the calculated attenuation data provided by CCIR model. Comparison of the calculated results with the data from the CCIR model shows that the method provides the ideal modeling of raindrop size distribution (DSD). As an application, the two‐year experimental data recorded in Singapore have been used to obtain another set of parameters of the gamma DSD function for the tropical region. © 1994 John Wiley & Sons, Inc.
EM plane‐wave diffraction by a material‐coated perfectly conducting half‐plane‐ oblique incidence
Authors: Ly H. C. , Rojas R. G. 
Published: July 2007

AbstractA high‐frequency solution is developed for the electromagnetic diffraction of an obliquely incident plane wave by a material‐coated perfectly conducting half‐plane. It is assumed that the coating is electrically thin so that it can be modeled by a generalized impedance boundary condition of O(t), where t is the coating's thickness. © 1994 John Wiley & Sons, Inc.
Periodic wavelet expansions for analysis of scattering from metallic cylinders
Authors: Steinberg B. Z. , Leviatan Y. 
Published: July 2007

AbstractThe recent application of wavelet transforms in method‐of‐moments solutions for scattering problems is extended to cases involving metallic cylinders whose periphery contain a variety of length scale features ranging from smoothly varying large‐scale features to rapidly varying small‐scale ones. The basic idea is to first consider a periodic extension of the equivalent current in the arc‐length variable with a period identical to the scatterer circumference, and then to expand this representation, using a set of periodic wavelets derived from a conventional basis of wavelets by a periodic extension. Using a Galerkin method and subsequently applying a threshold procedure, a substantial reduction in the number of elements of the moment‐method matrix is attained without virtually affecting the solution accuracy. The proposed extension is illustrated by a numerical study of TM (transverse magnetic) scattering from a cylinder of elliptic cross section. © 1994 John Wiley & Sons, Inc.
Characterization of single‐mode graded‐index fibers: A new method based on transverse offset splice loss
Authors: Hosain S. I. , de Fornel F. , Goudonnet J. P. 
Published: July 2007

AbstractA method of characterization has been proposed for single‐mode graded‐index fibers using knowledge of the power transmission coefficient at the splice as a function of transverse offset. The method utilizes an analytical expression for the power transmission coefficient based on a highly accurate variational approximation for the LP01 mode developed earlier. The method accurately predicts the profile shape parameter and the normalized frequency of the fiber. © 1994 John Wiley & Sons, Inc.
An optically preamplified PPM threshold detection receiver for satellite communications
Authors: Cryan R. A. , Phillips A. J. , Senior J. M. 
Published: July 2007

AbstractA novel scheme for the utilization of optically preamplified (EDFA) PPM receivers in intersatellite laser communications is proposed. Instead of employing a photon counting strategy, we have considered a threshold detection system. Using our model with conservative parameters, we have demonstrated potential receiver sensitivities of 40 photons/bit. This compares well with other results in the field and indicates the great potential of this receiver formation for use in satellite communications. © 1994 John Wiley & Sons, Inc.
Dual‐mode dielectric‐resonator microwave active filters
Authors: Delpino F. , Madrangeas V. , Billonnet L. , Jarry B. , Guillon P. 
Published: July 2007

AbstractThe purpose of this article is to present a new miniature dielectric‐resonator (DR) dual‐mode active filter. Measured results for a two‐pole bandpass active filter using dielectric‐resonator dual HEM118 mode are described. © 1994 John Wiley & Sons, Inc.
Comparison of InGaAs/InP photodetectors for microwave applications
Authors: Peredo E. , Decoster D. , Gouy J. P. , Vilcot J. P. , Constant M. 
Published: July 2007

AbstractThe purpose of this article is to compare the microwave performance of three photodetector types, an InGaAs/InP p‐i‐n photodiode, an interdigitated InAlAs/InGaAs/InP metal‐semiconductor‐metal (MSM) photodiode, and an interdigitated InGaAs/InP photo‐conductor (PC). Static and dynamic characterizations have been carried out at 1.3‐μm wavelength using a directly modulated laser diode. Our experiments show that photoconductive detectors exhibit the best sensitivity for frequencies up to 3 GHz. © 1994 John Wiley & Sons, Inc.
Use of correlation functions to assist the experimental validation of numerical modeling techniques
Authors: Duffy A. P. , Woolfson M. S. , Benson T. M. 
Published: July 2007

AbstractNumerical modeling has an important role to play in optical, microwave, and EMC design. An objective assessment of the accuracy of such numerical modeling tools using experimental data is often hampered by the general complexity of the data to be compared. It is therefore difficult to quantify the resulting comparisons. This communication suggests that three parameters derived from correlation functions can prove useful in assessing validation comparisons. © 1994 John Wiley & Sons, Inc.
Resonance frequency of a superstrate‐loaded annular‐ring microstrip structure on a spherical body
Authors: Chen Horng‐Dean , Wong Kin‐Lu 
Published: July 2007

AbstractWe report on the resonance problem of a superstrate‐loaded annular‐ring microstrip structure on a spherical body. This study is performed by using a Green's‐function formulation in the spectral domain and a moment‐method calculation. Numerical results of the resonant frequency and quality factor of the structure are presented. Both cases of the structure, used as a radiator at TM12 mode and as a resonator at TM11 mode, are studied. A great superstrate loading effect is observed for the structure excited at the TM12 mode as a radiator. Details of the results are presented. © 1994 John Wiley & Sons, Inc.
Annular ring microstrip antenna on a spherical body
Authors: Tam W. Y. , Lai A. K. Y. , Luk K. M. 
Published: July 2007

AbstractA theoretical analysis on the radiation pattern and the radiation resistance of an annular ring microstrip antenna mounted on a spherical body using an electric surface current model is presented. The effects of the dielectric layer and the metallic sphere are rigorously taken into account by the Green's functions in the spectral domain. Results for the antenna operating in the TM01 (wraparound antenna) and TM12 modes are given. © 1994 John Wiley & Sons, Inc.
A low‐cost etched linear slotted waveguide array
Authors: Roberts A. R. , Joubert J. 
Published: July 2007

AbstractChemical etching and deposition techniques have been used to fabricate longitudinal slots for a linear slotted waveguide array operating at 15 GHz. A comparison between computed and measured data for the antenna radiation pattern demonstrates the success of this low‐cost and accurate fabrication method. © 1994 John Wiley & Sons, Inc.
Analysis of shielding effects on the microstrip effective dielectric constant by the finite‐element method
Authors: Medina José L. , Javier Mendieta F. , Ku Walter H. 
Published: July 2007

AbstractStructures having symmetrically centered microstrip lines enclosed in a metallic waveguide are analyzed by the finite‐element method. Single and combined shielding effects on the microstrip effective dielectric constant due to a top cover and two side walls are investigated. A finite‐element computer program has been written in Fortran for a supercomputer to obtain very accurate numerical results by means of the solution of a very large system of linear equations. In addition, a new set of accurate empirical equations adequate for CAD to take both effects into account has been developed. Results are compared with other numerical and empirical methods, and discussions are also presented. © 1994 John Wiley & Sons, Inc.
Binary‐encoded matrix‐matrix multiplication architecture based on correlation by shadow casting
Authors: Zhou Changhe , Liu Liren 
Published: July 2007

AbstractA new binary‐encoded matrix‐matrix multiplication architecture based on correlation by shadow casting is presented. It can perform a binary‐encoded matrix‐matrix multiplication in a fully parallel manner to gel the mixed‐binary output matrix in the focal plane of the lens. Both the advantages and the disadvantages of the proposed architecture are carefully discussed. The proof‐of‐principle experiments demonstrate the effectiveness of the proposed architecture. © 1994 John Wiley & Sons, Inc.
Exact expressions for the ac resistance and internal inductance of a lossy circular two‐wire transmission line
Authors: Wang Bing‐Zhong 
Published: July 2007

AbstractIn this article, under the quasi‐TEM assumption, through an exact electromagnetic field analysis, we give an analytic solution for the current density inside the conductors of a lossy circular two‐wire transmission line, and finally obtain the exact expressions for the ac resistance and internal inductance at an arbitrary frequency. © 1994 John Wiley & Sons, Inc.
On symmetry in microstrip antenna analysis
Authors: Sǒipusǒ Zvonimir , Bartolić Juraj , Milin Zǒeljka 
Published: July 2007

AbstractAn application of the patch shape symmetry for the basis‐function selection for the Green's function/Galerkin's solution is reported. As a result many impedance matrix elements are equal to zero and the computation time is reduced. The symmetry properties of four commonly used microstrip patch antennas are described as examples. © 1994 John Wiley & Sons, Inc.
A multilevel algorithm for solving a boundary integral equation of wave scattering
Authors: Lu Cai‐Cheng , Chew Weng Cho 
Published: July 2007

AbstractIn the solution of an integral equation using the conjugate gradient (CG) method, the most expensive part is the matrix‐vector multiplication, requiring O(N2) floating‐point operations. The fast multipole method (FMM) reduced the operation to O(N15). In this article we apply a multilevel algorithm to this problem and show that the complexity of a matrix‐vector multiplication is proportional to N (log(N))2. © 1994 John Wiley & Sons, Inc.
Adaptation of the fdtd method to the study of femtosecond electromagnetic soliton
Authors: Reineix A. , Ariaudo M. , Jecko B. , Barthelemy A. , Froehly C. 
Published: July 2007

AbstractThis article introduces a theoretical method based on the resolution of Maxwell's equations in the time domain using an extended version of a FDTD algorithm. This approach allows the modeling of optical pulse propagation in nonlinear media; for this, dispersive and nonlinear models have been introduced in the code. Two versions of the method are proposed, the accuracy of this approach is shown, and then some results on the propagation of a soliton are given. © 1994 John Wiley & Sons, Inc.
An empirical resonant frequency prediction of k‐ and v‐band dielectric resonators
Authors: Desclos L. , Madihlan M. 
Published: July 2007

AbstractThis Letter deals with the optimum design of shielded dielectric resonators, with a dielectric constant around 24, for millimeter‐wave oscillator stabilization. Extending the Itoh et al. and Kaifez models, an empirical formula is devised that explicitly determines the optimum dielectric resonator dimensions and the shield height for a desired resonant frequency under the maximum achievable unloaded quality factor. © 1994 John Wiley & Sons, Inc.
Time‐domain analysis of kerr electro‐optic cells for high‐voltage pulse measurements
Authors: Brandao Farla J. A. 
Published: July 2007

AbstractThe time‐domain behavior of Kerr modulators operating under pulse voltage conditions is analyzed and discussed. Comparison with the ordinary quasistatic approach is established, showing the inadequacy of the latter. © 1994 John Wiley & Sons, Inc.
A method of generation of sum and sls‐type difference patterns
Authors: Sridevi P. V. , Raju G. S. N. , Chakraborty Ajoy , Das B. N. 
Published: July 2007

AbstractThe article presents a method of realization of useful sum and sidelobe‐suppressed difference patterns using only one array antenna. The method involves the synthesis of phase functions required for the generation of desired patterns. Computed results on radiation patterns are presented both for a continuous line source and an array of radiators © 1994 John Wiley & Sons, Inc.
A 3D perfectly matched medium from modified maxwell's equations with stretched coordinates
Authors: Chew Weng Cho , Weedon William H. 
Published: July 2007

AbstractA modified set of Maxwell's equations is presented that includes complex coordinate stretching along the three Cartesian coordinates. The added degrees of freedom in the modified Maxwell's equations allow the specification of absorbing boundaries with zero reflection at all angles of incidence and all frequencies. The modified equations are also related to the perfectly matched layer that was presented recently for 2D wave propagation. Absorbing‐material boundary conditions are of particular interest for finite‐difference time‐domain (FDTD) computations on a single‐instruction multiple‐data (SIMD) massively parallel supercomputer. A 3D FDTD algorithm has been developed on a connection machine CM‐5 based on the modified Maxwell's equations and simulation results are presented to validate the approach. © 1994 John Wiley & Sons, Inc.
Design and characteristics of a periodic butterworth‐like blocking filter using an s‐shaped two‐coupler optical fiber ring resonator
Authors: Ja Y. H. 
Published: July 2007

AbstractWe present the design and output characteristics of a periodic Butterworth‐like blocking filter using the transmitted output intensity of an S‐shaped optical fiber ring resonator with two 2 × 2 fiber couplers. Performance parameters of the periodic Buttenworth‐like blocking filter, including the ripple, the contrast, the bandwidth, and the maximum output intensity, are evaluated, and the design procedures are given. © 1994 John Wiley & Sons, Inc.
On the performance of different AR methods in the spectral estimation of FDTD waveforms
Authors: Jandhyala Vikram , Michielssen Eric , Mittra Raj 
Published: July 2007

AbstractIn the past, several extrapolation techniques have been used in conjunction with the finite‐difference—time‐domain algorithm to reduce the computational cost involved in obtaining an accurate representation of the frequency response of the electromagnetic system under consideration. In this article we study the performances of different autoregressive techniques in accurately estimating the spectra of finite‐difference—time‐domain waveforms without resorting to extrapolation. The advantages and disadvantages of these techniques are demonstrated through two examples: a package plane structure and a cavity. © 1994 John Wiley & Sons, Inc.
The chromatic dispersion of optical guiding structures by an approximation of numerical results
Authors: Valentinuzzi Elvio 
Published: July 2007

AbstractThe guiding structures in photonic and integrated optical circuits have complex geometries and refractive‐index profiles so that numerical methods must be used to analyze them. When it is necessary to evaluate parameters such as group delay or dispersion coefficient, which involve first and second derivatives of the numerically calculated propagation constants of the modes, the required accuracy is not easy to obtain. Suitable functions may be used to fit, in a least‐squares sense, the numerical solutions and to easily obtain derivatives from a direct analytical calculation. © 1994 John Wiley & Sons, Inc.
Attenuation and handedness of axial propagation modes in a cholesteric liquid crystal
Authors: Nagle Steven F. , Lakhtakia Akhlesh 
Published: July 2007

AbstractThe interplay of spatial and temporal periodicities in a cholesteric liquid crystal is responsible for the three zones into which axial propagation may be classified. Each of the three zones is marked by specific attenuation and handedness characteristics. © 1994 John Wiley & Sons, Inc.