bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of step discontinuities in dielectric‐slab and dielectric‐loaded waveguides using geometric‐optics approach
Authors: Yu Cheng‐Cheh , Chu Tah‐Hsiung 
Published: July 2007

AbstractIn this article calculations of power components transmitted and reflected at the step discontinuities in dielectric‐slab and dielectric‐loaded waveguides are presented using the geometric‐optics approach. Step discontinuities regarding the dielectric slab thickness and refractive index are considered. Numerical results are shown to be in good agreement with those of other rigorous methods. The computation involved in this approach is efficient since the associated mathematical formulation can be analytically expressed from the geometric optics point of view. © 1992 John Wiley & Sons, Inc.
Effect of metallization process on the performance of passive microstripline circuits
Authors: Puri Vijaya 
Published: July 2007

AbstractThe coupling and isolation of a 10‐dB directional coupler, midband rejection of Δ/2 rejection filter, and transmission and reflection coefficients of microstriplines are studied in the X band (8–11 GHz). The circuits are delineated photolithographically on alumina substrates metallized by aluminum and copper using different metallization processes. The adhesion and dc resistivity are also compared. The microwave properties do not show appreciable differences due to the various metallizations, though dc ion plating + electroplating seems to be the best of the lot. It has also been found that aluminum under proper conditions of deposition proves to be as good a conductor for microwave purposes as copper, and in some cases better. It is felt that using ion plating initially to get a thickness of ∼2000 Å and then electroplating to 4 μn thickness will be very cost effective, the film having the advantages of the good adhesive property of ion plating and less wastage of costly pure material. © 1992 John Wiley & Sons, Inc.
A Mach‐Zehnder interferometer made of strip‐loaded outdiffusion guide
Authors: Lau Chi‐Sang , Liu Shuh‐Fang , Wei Pei‐Kuen , Wang Way‐Seen 
Published: July 2007

AbstractThe electro‐optic (EO) characteristics of the strip‐loaded outdiffusion guide (SLOG) [1] are presented. A Mach‐Zehnder interferometer using the SLOG technique is fabricated for test. The results show that the EO effect is greatly enhanced and the extinction ratio is also larger compared to those made by the conventional titanium indiffusion technique. Moreover, the fabrication takes less time, yet the waveguide has no surface guide and less damage. Experimental and computer‐simulated results are also shown for comparison. © 1992 John Wiley & Sons, Inc.
Calculation of S parameters from abcd parameters with complex normalizing impedances
Authors: Frickey Dean A. 
Published: July 2007

AbstractExpressions for the conversion between ABCD parameters and S parameters are derived without making assumptions as to the nature of the normalizing impedances. The resulting equations contain the port 1 normalizing impedance Z01, and the port 2 normalizing impedance Z02, and are valid even when these are complex. © 1992 John Wiley & Sons, Inc.
A new differential calibration for radar cross‐section measurements
Authors: Desclos L. , Chassay G. , Pouliguen P. 
Published: July 2007

AbstractThis article presents an extension of the classical calibration method for RCS measurements on vectorial network analyzer. The classical one [1, 2] is based on the dynamical range of the measurement system with a single reference, which causes distortion if the target return level is very low compared to the calibration reference. The new differential method uses at least two measurements of known targets and contributes a reference to the system in addition to the classical method. In addition a new dynamical scaling is developed using this technique. This is very important in the measurement of targets with a wide dynamical return range. The application of this method is compared to the existing one. ©John Wiley & Sons, Inc.
Open‐boundary relaxation
Authors: Simpson Ted 
Published: July 2007

AbstractThe relaxation technique for computing the electrostatic potential in 2D is extended to open‐boundary problems. Two methods are introduced for updating the outer boundary potential between iterations using a numerical Green's function. Comparisons with conventional grounded‐boundary results show that greatly increased accuracy is obtainable with the open‐boundary method. © 1992 John Wiley & Sons, Inc.
Acousto‐optic wavelength division multiplexing system
Authors: Helaly Anwar , Abushagur Mustafa A. G. 
Published: July 2007

AbstractA novel wavelength division multiplexing/demultiplexing (WDM) system using acousto‐optic Bragg cell is presented. The system is adaptable for any wavelength deviation of light sources caused by temperature changes and allows changing the operating wavelengths over a wide range. High diffraction efficiency, high resolution, and a large number of channels are obtained. Computer simulation for a five‐channel system in the 0.8‐μm region is presented. © 1992 John Wiley & Sons, Inc.
Combined effects of microstrip width and substrate height on complex mode frequency range of boxed microstrip lines
Authors: Huret F. , Kennis P. , Pribetich P. 
Published: July 2007

AbstractIn this Letter we show, using the classical spectral domain approach modified by asymptotic expansions, the evolution of the frequency range of complex modes of boxed microstrip lines for several sets of physical and geometrical parameters. © 1992 John Wiley & Sons, Inc.
Asymptotic formulations for the wedge diffracted field
Authors: Vaudon P. , Jecko B. , Reineix A. 
Published: July 2007

AbstractIn this article the notion of transition function is reviewed under a mathematical form: Two methods are explored which respectively lead to two different transition functions. They are used to make asymptotic evaluations of an exact integral representation. Original analytic formulations are established. Their main properties are presented and compared with other diffraction coefficients which already exist. Several numerical computations allow us to give an idea of the accuracy of each formulation. © 1992 John Wiley & Sons. Inc.
Analysis of a microstrip step discontinuity fabricated on a metal‐insulator‐semiconductor (MIS) substrate
Authors: Livernols Thomas G. , East Jack R. 
Published: July 2007

AbstractA space‐domain coupled integral equation analysis is used to compute the two‐dimensional surface current distribution on a basic microstrip step discontinuity fabricated on an MIS substrate. The two‐port scattering parameters are computed from the surface current and their accuracy is verified through comparison with a measured data. © 1992 John Wiley & Sons, Inc.
Thin‐film boundary conditions
Authors: Jeng Shyh‐Kang , Lee Shung‐Wu 
Published: July 2007

AbstractA set of boundary conditions for general thin‐film structures is derived, which includes special cases of a resistive card and a thin coating over perfect electric conductors. The use of such boundary conditions in an analytical method, the method of moments, or the finite element method offers three distinct advantages: (i) the boundary conditions are much simpler, which makes the integral equation or the variational equation formulation simpler, (ii) the number of unknowns is reduced, and (iii) the numerical solution is more stable. © 1992 John Wiley & Sons, Inc.
Theoretical evidence for the near‐cosinusoidal electric field distribution of edge slots in rectangular waveguide
Authors: Jacobs J. Pieter , McNamara Derek A. 
Published: July 2007

AbstractA method‐of‐moments surface patch formulation has been applied to examine edge slots in rectangular waveguide. The electric field in the aperture and the vicinity of the slot is computed using the solution for the current distribution on the waveguide walls. The results of such “numerical experimentation” are described in this article. The slot field distribution is shown to be near‐cosinusoidal, with discontinuities at the corners of the waveguide which are more marked than has been shown previously. © 1992 John Wiley & Sons, Inc.
Analysis of a monopole in a substrate
Authors: Kwok Sai Chong 
Published: July 2007

AbstractA variational formulation of self‐impedance and mutual impedance of an electrically short vertical monopole above an infinite ground plane in a substrate is presented in this article. A comparison of self‐impedance with results from a mixed‐potential integral equation formulation and a comparison of mutual impedance with results from the method of moments are given. © 1992 John Wiley & Sons, Inc.
Input impedance of circular‐disk microstrip antennas with a dielectric cover
Authors: Fan Zhibo , Lee Kal‐Fong 
Published: July 2007

AbstractA spectral‐domain analysis of a coaxially fed circular‐disk microstrip antenna with a dielectric cover is presented. Numerical results are given on input impedance, resonant frequency, and impedance bandwidth of the TM11 mode. It is found that the dielectric cover reduces the resonant frequency, decreases the resonant resistance, and increases the impedance bandwidth. © 1992 John Wiley & Sons, Inc.
On the rigorous mode identification techniques in the shielded MICS
Authors: Essaaidi Mohamed 
Published: July 2007

AbstractIn this article four different mode identification techniques (ITs) are presented for the rigorous elimination of the moments method parasitic solutions (modes), propagating in a shielded microwave integrated circuit (MIC). These techniques involve mathematical models which have been developed from physical considerations concerning the nature of these modes. © 1992 John Wiley & Sons, Inc.
Field distortion in a longitudinal slot radiator in a slotted‐waveguide array
Authors: Wang Hanyang , Sangster A. J. 
Published: July 2007

AbstractA direct moment method is employed to examine the electric field distortion, due to mutual coupling, for a longitudinal slot radiator in a linear slotted‐waveguide array. A strict solution to the tangential field is obtained by employing a set of basis functions to simulate the field in the slots as a group. It is shown that while the mutual coupling between slots has significant influence on the amplitude of the slot aperture field, it has little impact on the shape of the field, even when the interfering slots are asymmetrically distributed in relation to the slot under examination. © 1992 John Wiley & Sons, Inc.
Novel monolithic phase shifter combining ferroelectrics and high temperature superconductors
Authors: Jackson Charles M. , Kobayashi June H. , Lee Alfred , Pettiette‐Hall Claire , Burch John F. , Hu Roger , Hilton Rick , McDade Jim 
Published: July 2007

AbstractWe describe a monolithic phase shifter which combines the low loss of high‐temperature superconductivity (HTS) with the variable dielectric properties of a ferroelectric material SrTiO3. Phase shifts greater than 28 degrees per wavelength were observed around 30° K. The compatibility of YBa2Cu3O7‐x and other ferroelectric materials is discussed. © 1992 John Wiley & Sons, Inc.
Application of convolution approach for microstrip lines on ferrite substrate
Authors: Hindy Moataza A. , Mitkess A. A. , Elsohly A. A. 
Published: July 2007

AbstractThe normalized longitudinal and transverse current distributions of a microstrip line on a ferrite substrate are obtained using the spectral domain approach for vertical magnetization. The dispersive properties of the line [characteristic impedance and effective permeability μeff (f)] are accurately evaluated. The new current distributions speed up the numerical computation of the parameters at different frequencies. © 1992 John Wiley & Sons, Inc.
Application of the network theory in one‐dimensional inverse scattering
Authors: Cul T. J. , Liang C. H. 
Published: July 2007

AbstractFor a half‐space barrier potential, it has been shown that the potential functions in a'shallow region 0 > x > d can be accurately reconstructed by using a generalized Born approximation from the reflection coefficient r(k) at x = 0, and the reconstructed error is notable when x < d. By using the network theory presented in this article, we can transform the reflection coefficient at x = 0 into the one at x = d, from which the potential functions of the region x < d can be accurately reconstructed. Numerical examples are given, which show the applicability of this method. © 1992 John Wiley & Sons, Inc.
Enhanced correlation discrimination using binary joint transform correlation with feedback
Authors: Alam M. S. , Karim M. A. 
Published: July 2007

AbstractThe correlation peak intensity in a binary joint transform correlator (JTC) usually decreases as the number of objects in the input scene increases. This problem is solved by incorporating additive feedback in a binary JTC to update the input plane information on the basis of correlation plane information. © 1992 John Wiley & Sons, Inc.
An analysis of the frequency limitations of an Alx GA1‐xAs/GaAs optical modulator
Authors: Tabib‐Azar M. , Claspy P. C. , Chorey C. , Bhasin K. B. 
Published: July 2007

AbstractFrequency response of an optical modulator, operating at λ = 0.83 μm and utilizing the linear electro‐optic (Pockels) effect in a Mach‐Zehnder configuration using an AlxGa1‐xAs/AlyGa1‐yAs double heterostructure, is analyzed. We show that in semiconductor modulators, electroabsorption should be taken into account in optimizing the frequency response of the device. © 1993 John Wiley & sons, Inc.
Light interaction with GaAs mesfet and its applications— a review (invited paper)
Authors: Madjar A. , Paollela A. , Herczfeld P. R. 
Published: July 2007

AbstractThe GaAs MESFET is a light‐sensitive device. For normal microwave applications this is considered an undesirable property, and device manufacturers attempt to minimize it. In the last decade researchers discovered ways of utilizing this effect. In this article we present briefly the optical detection properties of the MESFET and describe some typical applications. © 1993 John Wiley & sons, Inc.
Direct optical subharmonically injection‐locked mesfet oscillators
Authors: Higgins Thomas P. 
Published: July 2007

AbstractReported here are the results of direct optical subharmonically injection‐locked oscillators at 5.455 and 15.011 GHz. Multiplication of subharmonics was achieved mainly by overmodulation of a laser diode. Significant locking ranges were attained, and subharmonic factors of up to 1/15 were used. © 1993 John Wiley & sons, Inc.
Proposal of fiber and radio extension link for future personal communications
Authors: Komaki Shozo , Tukamoto Katutoshi , Hara Shinsuke , Morinaga Norihiko 
Published: July 2007

AbstractThis article proposes a fiber and radio extension link (FREx Link) that offers the advantage of enhancing the flexibility of the various communication systems. In this article, two examples of applications for FREx Link, the intercell connection link (ICCL) and the fiber to the area system (FTTA), are described. Some numerical results of the system design considerations are given for each example. © 1993 John Wiley & sons, Inc.
A study of high‐order modes in a quasi‐optical cavity
Authors: Ge Junxiang 
Published: July 2007

AbstractIn this article the vector field of TEMpl modes in a concave spherical quasioptical cavity is investigated by the complex source point theory (CSPT) and multipole theory (MT). The resonant frequencies for TEMpl‐modes are also obtained. © 1993 John Wiley & sons, Inc.
Bistatic scattering for a finite lossy cylinder
Authors: Murphy R. A. , Christodoulou C. G. , Phillips R. L. 
Published: July 2007

AbstractThe problem of scattering from a finite conductive cylinder with complex permittivity at arbitrary orientation is analyzed using a first‐order approximation to an iterative technique developed by Shifrin. The classical Kerker solution for a simple infinite dielectric cylinder is extended to a more physically realistic solution accounting for a finite‐length cylinder with frequency‐dependent complex permittivity using a modified Drude conductivity approach. The polarization matrix of the cylinder is derived from the electrostatic solution for a finite cylinder in a uniform electric field, and it is given as a function of the length‐to‐diameter ratio (aspect ratio) and the permittivity of the cylinder. The electrostatic solution for a finite cylinder does not permit a closed solution; therefore the cylinder is approximated by an inscribed ellipsoid which provides a converging analytic expression. The effects of typical variations in the length, diameter, and bulk conductivity of the cylinder were analyzed for TE, TM, and TEM polarizations. © 1993 John Wiley & sons, Inc.
Scattering of electromagnetic waves from a time‐varying fractal surface
Authors: Chen Ji , Lo Titus , Litva John , Leung Henry 
Published: July 2007

AbstractA time‐varying band‐limited fractal model is proposed for modeling rough surfaces. The Kirchhoff approximation is used to obtain the backscattering field from this surface. A K‐distributed intensity fluctuation is observed for the distribution of the field amplitude. When the numerical results are compared with previous experimental work [1], good agreement is observed. © 1993 John Wiley & sons, Inc.
Generation of accurate broadband information from narrowband data using the cauchy method
Authors: Adve R. S. , Sarkar T. K. 
Published: July 2007

AbstractThe Cauchy method has been used to extrapolate a desired parameter over a broad range of frequencies. This information is generated using some information about the parameter at some discrete frequency points in a narrow range. The approach is to assume that the parameter is a rational function of frequency. The problem is to determine the order of the polynomials and the coefficients therein. The method of total least squares is used to solve the resulting matrix equation. This method can be coded as a stand‐alone program for parameter extrapolation or incorporated as part of a larger analysis program. The Cauchy method has yielded accurate results when used in conjunction with a method‐of‐moments program and as an independent program in device characterization. © 1993 John Wiley & Sons, Inc.
A generalized Gel'fand‐Lavitan equation for purely conducting layered media with applications
Authors: Shi Xiaowei , Liang Changhong 
Published: July 2007

AbstractThe conductivity profile inversion for purely conducting media is studied. Presently, some approximation inversion formulations are given for this problem. In this Letter, a generalized Gel'fand‐Lavitan equation is given for exact inversion. Like the famous GL equation, the generalized GL equation is exactly solvable when the reflection coefficient is a rational function. Reconstruction examples are also given. © 1993 John Wiley & Sons, Inc.
Improved performance of power‐efficient topologies for wdm optical sensor networks using an extended spectral‐width broadband led
Authors: Senior J. M. , Moss S. E. , Cusworth S. D. 
Published: July 2007

AbstractThe provision of WDM multiple optical point‐sensor networks is examined by modeling the power budgets required for their implementation. A larger number of distributed optical point sensors are indicated than previously obtained by using an extended spectral width broadband LED together with two power‐efficient WDM sensor network topologies. © 1993 John Wiley & Sons, Inc.
Wide‐range variable‐bandwidth microstrip patch antenna using electromagnetic coupling
Authors: Yousefi M. H. , Aiyer R. C. , Vaitheeswaran S. M. , Karekar R. N. 
Published: July 2007

AbstractThe rectangular microstrip putch antenna (RMPA) and square microstrip patch antenna (SMPA), designed to resonate at about 10 GHz, are excited by a electromagneticully coupled microstrip line. The effect of variation in the offset and inset of the feed line on resonating frequency (fr), VSWR, and impedance bandwidth (BW) are experimentally studied using alumina substrate. It is seen that SMPA gives the highest BW of 4.98% for diagonal feed. The lowest BW obtained is for side‐fed SMPA (0.012%), with maximum variation in BW of 1:278. The best trade‐off to get such a variable BW easily, with only feed point adjustment using electromagnetic coupling for these patches, is to use a long‐side‐fed RMPA which gives sufficiently good BW variation of 1:98 and the lowest possible mismatch error, while adjusting the relative position of the feeder microstrip line. All the bandwidths mentioned above are only obtained when, simultaneously, VSWR < 2. Such an RMPA may also give multifrequency operation. © 1993 John Wiley & Sons, Inc.
Time‐frequency analysis of the scattering phenomenology in finite dielectric gratings
Authors: Moore John , Ling Hao 
Published: July 2007

AbstractThe short‐time Fourier transform is applied to analyze the backscattered signal from a finite dielectric grating. The resulting time‐frequency display provides a clear description of the different scattering mechanisms, including edge diffraction, surface Floquet reflection, and surface wave propagation. In addition, Floquet harmonics are found to be excited not only by the incident plane wave, but also by the surface waves launched at the edges of the grating. © 1993 John Wiley & Sons, Inc.
Numerical modeling of wave propagation in optical nonlinear couplers
Authors: Yuan Li‐Pen 
Published: July 2007

AbstractA numerical method is proposed and implemented for the analysis of propagation characteristics of nonlinear optical couplers. This technique is based on the shooting method. A fourth‐order Runge‐Kutta method is adopted to solve wave equations in the coupler. An error function is defined to estimate the discrepency between the computed and predicted boundary values. A secant method is then used to evaluate the correction term of the initial guesses. This procedure is performed iterationally for realization of nonlinear couplers with an arbitrary number of branches and varying parameters. © 1993 John Wiley & Sons, Inc.
Matrix perturbation theory of the eigenequation [A][u] = Δ[u] and its application in electromagnetic fields
Authors: Cui T. J. , Liang C. H. 
Published: July 2007

AbstractA novel matrix perturbation theory to the eigenequation [h][u] = Δ[u] is investigated, in which the perturbation solutions to eigenvalue Δ and eigenvector [u] are given. One of the applications of the above theory‐application in a microwave resonate cavity‐is researched. © 1993 John Wiley & Sons, Inc.
Active polarimetric microwave remote sensing of corn and multiparametric retrieval of corn parameters with an artificial neural network
Authors: Chen Zhengxlao , Tsang Leung , Kuga Yasuo , Chan Chi 
Published: July 2007

AbstractPolarimetric signatures of a corn canopy are studied with the vector radiative transfer theory. Comparisons are made with experimental data at L and C bands. Multiparametric inversions of corn canopy parameters are performed with an artificial neural network (ANN) trained with vector radiative transfer theory. We have performed simultaneous retrieval of three parameters: corn height, volumetric moisture of corn stalks, and volumetric soil moisture from a total of eight averaged Mueller matrix elements at L and C bands and at one incidence angle. It is shown that the performance of the neural network is good, with errors of less than 10%. It is also shown that the performance of the ANN is better if measurements at both frequencies are used and also if polarimetric measurements including information about the polarization phase difference are used. © 1993 John Wiley & Sons, Inc.
MIllimeter‐wave wideband frequency divider
Authors: Chen R. S. , Li X. G. , Sun M. S. 
Published: July 2007

AbstractIn this article a novel configuration used as a wideband frequency divider is presented. When the bias of varactor in the circuit is properly adjusted, the experiments show that such a wideband divider can operate in the 31–36 GHz range with a small input power level. © 1993 John Wiley & Sons, Inc.