bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new electromagnetically coupled printed ring radiator
Authors: Sastry N. N. , Lakshminarayana M. 
Published: July 2007

AbstractA new type of printed radiator has been designed, fabricated, and tested. This radiator is in the form of an annular ring with a narrow break in the form of a slot. The antenna is fed by a microstripline and has yielded a VSWR less than 2.0 over a 20% band width. Because of its low profile construction and large bandwidth, this antenna can find wide application as an element radiator in phased array antennas.
Thin‐film permanent magnet requirements for magnetic devices in MMIC
Authors: Stancil Daniel D. 
Published: July 2007

AbstractThe use of sputtered thin‐film permanent magnets for biasing microwave devices in planar geometries compatible with monolithic integration is considered. Possible geometries are presented for biasing a reciprocal microstrip phaser at 7 GHz, a stripline circulator at 15 GHz, and a magnetostatic wave delay line at 3 GHz. Yttrium iron garnet (YIG) is assumed to be the ferrite used in each of these devices. It is concluded that the in‐plane magnetization orientation is more useful than normal magnetization, and thick films (100‐150 μm) are needed with high magnetization ( > 16 kG) and moderate coercivity ( > 2 kOe). Below‐resonance devices are preferable because of their modest field requirements and tolerance to bias field inhomogeneities.
Correlation with a phase‐only matched filter made from outline feature
Authors: Minhua Liang , Min Yu , Liren Liu , Shudong Wu , Zhijiang Wang 
Published: July 2007

AbstractTo obtain a high correlation peak intensity, a high optical efficiency, and high rotation and scale sensitivities, a new method, which can be realized optically, is proposed. Computer simulation results show that this method will have a neater output and better sensitivities than phase‐only matched filter.
Theoretical analysis of the breakdown voltage in InP MISFETs
Authors: de Jaeger J. C. , Fellon P. , Kozlowski R. , Crosnier Y. , Salmer G. 
Published: July 2007

AbstractThe theoretical avalanche breakdown in InP MISFETs is described using a two‐dimensional numerical model based on the calculation of Poisson's equation and the current equation. The study investigates various structures with a full analysis of the potential shape and the electric field distribution which gives complete explanations of the breakdown behaviour of the device. The characteristics of the transistor are determined as a function of the geometry of the structure, and the effects of the main parameters are given: The gate‐drain distance, the insulator zone width, the channel thickness, the doping concentration of the active layer and the shape of the recess.
Scanning tunneling microscopy of thin film surfaces and film steps
Authors: Yue Lin , Xiangzhen Chen , Runwen Wang 
Published: July 2007

AbstractA novel technique of scanning tunneling microscopy applied to optical surfaces has been analyzed both in theory and experiment in this paper. The profiles of Al, Mo coated film surfaces and multilayer film steps are measured with the scanning tunneling microscope and stylus instrament, whose experimental results are compared and analyzed.
High‐efficiency variable‐power class‐B dual‐gate power fets
Authors: Bahl Inder , Geissberger Art , Griffin Edward 
Published: July 2007

AbstractWe report state‐of‐the‐art measured performance of class‐B dual‐gate GaAs power FETs fabricated using a highly manufacturable SAG technology. The class‐B devices use selective co‐implantation for FET channel formation and demonstrate 640 mW / mm (for 2.5 mm FETs) of power at C‐band with 45% PAE and 11.4‐dB gain.
Near‐field diffraction pattern by an underground void of circular cylinder
Authors: Lee Taek‐Kyung , Park Seong‐Ook , Ra Jung‐Woong , Kim Se‐Yun 
Published: July 2007

AbstractAmplitude patterns of the electromagnetic field scattered by a circular air cylinder embedded in a dielectric medium are analyzed. Twenty five decibel double dip patterns measured by the scale‐down experiment are presented. Theoretical analysis shows that these double dips become double nulls in the near‐field region. This phenomenon is useful in locating high‐contrast geological anomalies.
Propagation coefficient of the transverse electric mode in a rectangular waveguide with sinusoidally varying width
Authors: Li Guifang , Seshadri S. R. 
Published: July 2007

AbstractAn analytical expression is deduced for the propagation coefficient of the transverse electric mode in a rectangular waveguide with sinusoidally corrugated sidewalls by a perturbation procedure. The accuracy of the present treatment is of the same order as that of the previously obtained numerical results.
Magnitude and phase of the electric field of infinite‐strip, unstable optical resonators using different techniques
Authors: Rahnavard M. H. 
Published: July 2007

AbstractWe calculate the magnitude and phase of the electric field (eigenfunctions) in infinite‐strip, unstable optical resonators which are used in medium‐to‐high power lasers. In this paper physical optics (PO), scalar theory of diffraction (STD), physical theory of diffraction (PTD), approximate physical optics (POA), and geometrical theory of diffraction plus geometrical optics (GTD + GO) methods are used to compute the magnitude and phase of the electric field in infinite‐strip, unstable optical resonators. The results of these different methods are compared. The calculated power loss using eigenvalues corresponding to the calculated electric field (eigenfunctions) are in agreement with previously published calculations.
Band‐pass distributed amplifiers
Authors: Prasad S. N. , Beyer J. B. 
Published: July 2007

AbstractA novel band‐pass distributed amplifier design concept is presented. The amplifier can be realized in monolithic form using GaAs FETs. The amplifier has excellent wideband gain and phase response characteristics. It shows promise for applications in the millimeter wave region. In this paper the results of analytical modelling as well as computer simulations are discussed.
Analysis of an electrically long, all‐dielectric, fiber‐optic electric‐field sensor
Authors: Atkinson Leonard A. , Kruppa Walter 
Published: July 2007

AbstractAn electrically short fiber‐optic electric‐field sensor has a sensitivity that is proportional to the fiber length. In this paper an analysis is presented for a sensor with an electrically long fiber. The result indicates that zeros will occur in the frequency response. A sensitivity tapering technique is presented which prevents these zeros from occurring.
All‐optical cutoff modulation in gallium arsenide ridge waveguides
Authors: McWright G. , Ross B. 
Published: July 2007

AbstractWe discuss all‐optical cutoff modulation in gallium arsenide integrated optical ridge waveguides for a guide wavelength of 1.3 μ.m. These modulators use the change in refractive index due to electron‐hole pair generation to bring the waveguide to cutoff.
Mutual interaction of the first‐order soliton multipulse series in optical fibers
Authors: Guo Qi , Zhou Guosheng , Lin Weigan 
Published: July 2007

AbstractIt is pointed out that the split step method and the propagating beam method are equivalent and numerically calculated by the method that the initial equal separation first‐order multipulse series propagates in an optical fiber. A possible scheme to increase the bandwidth of an optical soliton communication system is proposed.
A 32 × 32 array for satellite reception
Authors: Russo P. , Ruggieri M. 
Published: July 2007

AbstractThe possible use of microstrip arrays for 12 GHz satellite reception has been evaluated. In particular a 32 × 32 element array has been synthesized that considers both a broadside solution and a beam‐steered approach.The interesting results that have been achieved show the great promise of planar arrays for end‐user applications.
Large deviation fsk baseband receiver using an optical multiport device
Authors: Betti S. , Curti F. , de Marchis G. , Iannone E. 
Published: July 2007

AbstractA new large deviation FSK baseband receiver is presented. It is based on an eight port optical multiport that provides phase‐quadrature detection so as to avoid aliasing when the input signal is baseband translated. The multiport device also provides insensitivity to laser intensity noise and suppresses channel intermodulation in FDM systems.
Fabrication of waveguide ‐ fiber array couplers using laser‐machined V‐groove techniques in perspex substrates
Authors: Chung P. S. , Hung W. Y. , Chan H. P. 
Published: July 2007

AbstractWe report an inexpensive and versatile technique for coupling multichannel waveguides to a fiber array using V‐grooves in perspex substrates that are accurately machined by a computer‐controlled CO2 laser system. An excess loss of less than 1 dB could be achieved for coupling between 1 × 2, 1 × 3, and 1 × 4 branching circuits and an array of N‐port fibers.
A phase quadrature square patch microwave coupler
Authors: Merugu L. N. , Fusco V. F. , Stewart J. A. C. 
Published: July 2007

AbstractTheoretical and experimental results are presented for a square microstrip patch employed as a coupler at 13.2 GHz. The square patch exhibits equal power‐split in phase quadrature over a 7% bandwidth, 5.0 dB coupling, and 17 dB isolation. The effect of packaging on the performance is investigated.
Effective dielectric parameter method — A new method for analyzing propagation characteristics of dielectric waveguides
Authors: Zhendong Shi , Jiang Li 
Published: July 2007

AbstractThe effective dielectric constant method is known for analyzing propagation characteristics of dielectric waveguides. In this paper we discuss the substance of this method. Further, an effective dielectric parameter method having higher accuracy is introduced. The agreement between experimental values and the values calculated by this method is shown to be quite good.
Microstrip bandstop and passband filters using gap discontinuities and shorted terminals
Authors: Faria J. A. Brandão 
Published: July 2007

AbstractThis paper presents an analysis of a transversally symmetric three‐line microstrip structure whose side lines have discontinuities. The device is shown to behave as a bandstop or as a passband filter depending on an asymmetry coefficient characterizing the discontinuity localization. Formulas for the filter parameters (attenuation, bandwidth, phase and group velocities, and characteristic wave impedance) are established and design examples are provided to illustrate the analysis results.
Error effects on the processing of adaptive array data using the BOC
Authors: Abushagur Mustafa A. G. 
Published: July 2007

AbstractThe Bimodal Optical Computer (BOC) is considered for Adaptive Phase Array Radar (APAR) data processing. The effect of the errors in the BOC and the number of iterations on the optimum weight calculations for the interference cancelling are studied. Computer simulations for five‐and nine‐element APARs are presented.
Restoration of blurred images due to linear motion using a joint transform processor
Authors: Cheng Feng , Xu Xin , Wu Shudong , Yu Francis T. S. , Gregory Don A. 
Published: July 2007

AbstractIn this paper we shall show that blurred photographic images due to linear motion can be restored with a joint transform processor (JTP). The deconvolution function for the image deblurring can be directly implemented at the input plane of a JTP. The bipolarity of the deconvolution function can be accomplished by encoding with a ±‐shifted grating structure. Computer simulations to test the feasibility of the scheme are given.
Mechanical displacement measurement by single‐mode fiber optic and moving mirror
Authors: Bakalidis George N. , Georgopoulos Chris J. 
Published: July 2007

AbstractIn this paper a theoretical model of a mechanical displacement sensor based on the theory of the optical Gaussian beam emerging from an optical single mode and the recoupling through a multimode optical fiber is presented. The developed model presents a dynamic region of measurements from 0 to 130 μm.
Radiation and surface waves of a microstrip antenna covered with a dielectric layer
Authors: Hoorfar Ahmad , Gupta K. C. , Chang D. C. 
Published: July 2007

AbstractThe effects of a thick cover layer on the radiation characteristics of a microstrip patch antenna are investigated. A magnetic line source model has been used to derive explicit expressions for the far field, radiated power, directivity, and surface wave of the antenna. Numerical results are presented to show the effects of a lossless as well as a lossy dielectric cover layer on the surface waves and the radiated power.
Experimental determination of the resonance frequencies of suspended‐substrate microstrip antennas
Authors: Lin C. C. 
Published: July 2007

AbstractA simple experimental method is presented which enables the determination of the resonance frequencies of suspended‐substrate microstrip antennas. Resonance frequencies have been measured in L‐band for square patch‐antennas in “suspended‐substrate” as well as in “inverted” configurations. The relationship between the above measured resonance frequencies and the input impedances of the corresponding patches is also shown.
Calculations on the increased sensitivity of dielectric constant measurements using open‐end coaxial line with a hemispherical center conductor extension
Authors: Xu Yansheng , Bosisio Renato G. 
Published: July 2007

AbstractIn this paper, the method of measurement of dielectric constant by using open‐ended coaxial lines with a hemispherical center conductor extension is examined in great detail. Calculation results show that this method can considerably improve the sensitivity of measurement while retaining the advantages of a simple mechanical construction. Such a probe is conveniently used with any material that can intimately embrace the hemispherical tip of the probe (e.g., liquids, fine powders, etc.).
Characteristic impedance for double‐sided slotlines
Authors: Coetzee Jacob C. , Malherbe Johannes A. G. 
Published: July 2007

AbstractComputed results on the characteristic impedance of double‐sided slot‐lines on low‐permittivity substrates are presented. Curves for ϵr= 2.22, 3.0, and 3.8 are included. A spectral Galerkin method is employed to calculate the slotline wave number and the slot electric field. The characteristic impedance is then calculated in the spectral domain from the slot field.
Near field radiation from four coaxial line fed structures
Authors: Nevels Robert D. , Ed Wheeler J. 
Published: July 2007

AbstractNear field time‐average power distribution and radiation direction patterns are presented for a coaxial line flush‐mounted on an infinite ground plane and terminated with (a) an infinite homogeneous half space, (b) a hemispherical extended center conductor, (c) a hemispherical dielectric cover, and (d) a hemispherical extended center conductor with a dielectric coating. Expressions are given for the electric and magnetic fields and Green's functions for the dielectric coaled conducting hemisphere case, from which the fields and Green's functions for the other three cases can be constructed. Each of the four structures described here is either in use or has potential applications as an antenna or as a component in an external medium dielectric constant measurement system.
Scattering of a tem wave from a time varying surface
Authors: Elcrat Alan R. , Harder T. Mark , Stonebraker John T. 
Published: July 2007

AbstractA solution is given for reflection of a plane wave with TEM polarization from a planar surface with time varying properties. These properties are given in terms of the currents on the surface. The solution is obtained by numerically solving a system of differential‐delay equations in the time domain.
A variable‐gain constant‐phase dual‐gate amplifier with series feedback
Authors: Willems David , Bahl Inder , Pollman Mike , Coluzzi Michael , Tantod Shukdev , Andricos C. 
Published: July 2007

AbstractThis paper presents series feedback used in a variable‐gain constant‐phase dual‐gate amplifier for T / R module applications. The inductive series feedback element shifts the input match of the dual gate FET to an impedance that is much easier to match 50 ohms. This allows the amplifier to have a much broader bandwidth and increased gain while maintaining constant phase in the different gain states. This amplifier was fabricated as a MMIC chip using the ITT MSAG process, and we obtained excellent performance: variable gain range of 13 dB, VSWR better than 2.0:1, phase variation less than ±2°, and gain flatness of ±0.4 dB over the 4.5‐6‐GHz frequency range.
An improved all‐fiber 90° optical hybrid
Authors: Kejian Guan , Yizun Wu 
Published: July 2007

AbstractIn this letter, an improved all‐fiber 90° optical hybrid is reported. The experimental unit has the following characteristics: low insertion loss, high stability, wide operation bandwidth, and simple fabrication process of all functional components. The unit will find applications in phase diversity coherent optical communication systems and interferometric sensing systems.
Characteristic modes for nonconducting bodies having mutually orthogonal symmetry planes
Authors: Vescovo Roberto , Corzani Tullio 
Published: July 2007

AbstractWe consider the characteristic modes of lossy or loss‐free dielectric and / or magnetic bodies symmetric with respect to mutually orthogonal symmetry planes. For such cases, we show that the moment method can be applied to the eigenvalue equation defining the modes, transforming it into a matrix eigenvalue equation involving matrices partitioned into diagonal blocks.
Green's function for the poisson equation in the domains bounded by two intersecting spheres
Authors: Lin Weigan , Jin Hang 
Published: July 2007

AbstractThe Green's functions for the Poisson equation in the domains bounded by two intersecting spheres with Dirichlet boundary conditions is presented. As an illustration of the application, the perturbation of a thick wall conducting spherical cavity with a circular aperature in a uniform static field is treated.
On phase‐shift position and linewidth of λ/4‐shifted DFB laser diodes
Authors: Ghafouri‐Shiraz H. , Chu C. Y. J. 
Published: July 2007

AbstractThe phase‐shift position (PSP) of a λ/4‐shifted distributed feedback (DFB) laser diode affects many characteristics of the laser. In particular, the effects of PSP on stability and external differential quantum efficiency for single longitudinal mode (SLM) operation of the laser were investigated previously by many authors. In this letter, a theoretical analysis of the effect of PSP on the spectral linewidth of the laser is presented. The results revealed the necessity of trade‐off in optimizing the PSP for a laser diode with a narrow linewidth while maintaining a sufficient stability and efficiency.
Monte carlo simulations of scattering of waves by a random rough surface with the finite element method and the finite difference method
Authors: Lou S. H. , Tsang L. , Chan C. H. , Ishimaru A. 
Published: July 2007

AbstractThe finite element and the finite difference methods are applied to Monte Carlo simulations of random rough surface scattering. The advantages of these methods are the banded nature of matrix and the reduction of computer time. These results are also compared with those of Kirchhoff approximation and those of small perturbation theory when applicable.
Theory and design of wideband 3‐dB suspended microstrip couplers with floating conductor
Authors: Karam Michel , Demers Yves , Xu Yansheng , Bosisio Renato G. 
Published: July 2007

AbstractUsing the spectral domain method, theoretical analysis of the characteristics of coupled suspended microstrip lines with floating conductor is presented in detail. The distributions of electrical charges on the coupled microstrip lines and floating conductor are studied, and a set of basis functions used in the calculation is obtained. Detailed numerical results and design curves are presented, and an experimental wideband 2.5‐dB coupler is designed and measured. The test results are in agreement with theoretical values. This type of coupler is simple in construction and capable of realizing tight coupling (3 dB or higher) in microwave integrated circuits (MIC) with high directivity.
High‐efficiency diffraction modulation of light by strain‐optic effect of piezoelectrically induced standing acoustic waves in bulk LiNbO3 crystal
Authors: Kuti Cs. , Turi I. , Yan Li , Lee Chi H. 
Published: July 2007

Abstract100% modulation of light was achieved by the strain‐optic effect of the piezoelectrically induced standing acoustic waves in a bulk LiNbO3 crystal. The modulation index as high as 4 was attained. As a result, in a single pass a continuous wave light has been modulated resulting in transmission peaks of width less than 2 ns at a repetition rate of 100 MHz.
Analysis of arbitrarily shaped COAX‐FED microstrip antennas—a hybrid mixed‐potential integral equation approach
Authors: Zheng Dalian , Michalski Krzysztof A. 
Published: July 2007

AbstractArbitrarily shaped coax‐fed microstrip patch antennas on thick substrates are studied using a hybrid mixed‐potential integral equation approach, which incorporates a triangle‐element model of the patch and a simplified treatment of the probe‐to‐patch junction. Computed input impedance data are shown to agree well with measured results.
Microwave characterization of high‐temperature superconducting thin films using stripline resonators
Authors: Macdonald Alan D. , Long Stuart A. , Williams Jeffery T. , Jackson David R. , Lichtenberg Christopher L. , Davis Matthew L. , Wosik Jaroslaw L. , Wolfe John C. 
Published: July 2007

AbstractA method was derived for the extraction of the surface resistivity (Rs) of high Tc superconducting (HTS) thin films at microwave frequencies using a stripline resonator circuit. Surface resistivity values were calculated by measuring the difference in Q‐values of a stripline resonator configuration when an HTS thin film was substituted for one of the metallic ground planes. Cryogenic tests were completed for several stripline resonator structures, yielding accurate predictions of the HTS thin‐film performance at frequencies between 3 and 26 GHz (in harmonics of approximately 3 GHz). These results were then used to illustrate the dependence of HTS surface resistivity on frequency and temperature in the microwave frequency band.
Measurements of signal transmission to 20 GHz and crosstalk to 10 GHz on small copper microstrips embedded in polyimide dielectric
Authors: Loos J. S. , Engvik A. H. , Lin M. S. , Lin‐Hendel C. G. 
Published: July 2007

AbstractMulti‐GHz measurements of signal propagation and crosstalk are reported for small, somewhat resistive, copper microstrips (20‐30 μm width and 2‐3 μm thickness) that are embedded in polyimide dielectric and fabricated on a silicon substrate. The transmission, reflection, signal velocity, and crosstalk on 50‐Ω terminated microstrips are well behaved and, moreover, are well described by standard transmission line theory when resistive losses (corrected for the skin effect) are included.
Optoelectronic implementation of local cellular logic with polarization coding
Authors: Zhang Li , Liu Liren 
Published: July 2007

AbstractAn optoelectronic architecture is suggested to perform local cellular logic. A polarization coding technique along with the electronic substraction and thresholding techniques are developed to complete the operations with both positive and negative interconnections. Experimental results of the Laplacian operator for edge enhancement and their numerical simulations are given.
A method for optimizing efficiency and power dissipations in high power microwave/ millimeter‐wave amplifiers
Authors: Larose Robert , Ghannouchi Fadhel M. , Bosisio Renato G. 
Published: July 2007

AbstractAn alternative method for large signal characterization of microwave / millimeter‐wave power transistors suitable for high power amplifier design is presented. Constant output power contours, constant added‐power efficiency contours, and constant power dissipation contours over the full Smith chart are obtained for a NEC 71083 MESFET.