bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dielectric‐loaded circular ridge waveguide applicator for hyperthermia
Authors: Beckman C. , Lundgren L. , Roos D. 
Published: July 2007

AbstractAn applicator for intracavitary hyperthermia treatment of cancer has been designed and tested. The applicator is a section of a dielectric‐loaded circular ridge waveguide closed at both ends to form a transmission cavity. An aperture in the cavity wall can produce a directed heating of a tumor growing in the wall of a body cavity such as the vagina.
Radar applications of 10‐GHZ fiber optic links
Authors: Newberg I. L. , Gee C. M. , Thurmond G. D. , Yen H. W. 
Published: July 2007

AbstractLong delay lines can improve the performance and flexibility of radar test sets. Using a 2.25‐km‐long fiber optic link, we demonstrated generation of an ideal target for a radar repeater test set and measurement of phase noise closer than 100 Hz to a 9.6‐GHz radar carrier signal using a delay line discriminator phase‐noise test set.
Adaptive array radar data processing using the bimodal optical computer
Authors: Abushagur Mustafa A. G. 
Published: July 2007

AbstractThe use of the bimodal optical computer (BOC) in determining the weights for an adaptive phased array radar is introduced. Interference canceling is presented for two cases: (1) assuming the direction of the jammer is known and (2) assuming no a priori information. The effect of the jammers on the array pattern is shown for up to four jammers.
Comparisons of the application of various conjugate‐gradient algorithms to electromagnetic radiation from conducting bodies of revolution
Authors: Davidson David B. , McNamara Derek A. 
Published: July 2007

AbstractDescriptions are given of the application of the classical conjugate‐gradient (CG) matrix solution algorithm and variants thereof (three types of preconditioner and the biconjugate gradient method) to the matrix equations obtained on application of the moment method to the reduced subproblems describing radiation from conducting bodies of revolution, and the associated numerical results. A recent debate in the literature on the interpretation of the application of CG methods to electromagnetic problems is put in perspective.
Efficient characterization of multilevel interconnections on the gaas‐based VLSICs
Authors: Goel A. K. , Huang Y. R. 
Published: July 2007

AbstractAn efficient numerical technique for the characterization of the single‐and multi‐level interconnections on the GaAs‐based VLSIs is presented. The algorithm employs an efficient and more flexible network analog method suitable for the finite‐dimensional interconnection configurations on the GaAs substrate.
Characteristic impedance of a curved microstrip transmission line
Authors: Roy J. S. , Poddar D. R. , Mukherjee A. , Chowdhury S. K. 
Published: July 2007

AbstractModification of Wheeler's expression for the characteristic impedance of a straight microstrip transmission line is derived for the computation of the characteristic impedance of a curved microstrip transmission line. Good agreement between computed and measured data is obtained.
A compact biconical dual‐mode feed for low‐cost offset reflector antennas
Authors: Maniá Lucio , Vatalaro Francesco 
Published: July 2007

AbstractThis paper describes a version of the dual‐model feed horn that is considered particularly suitable for application in receive‐only reflector antennas. Even though it was originally presented many years ago, to the authors' knowledge this type of biconical feed horn has not previously been analyzed or utilized. The present paper aims to describe the potential advantages of this feed horn for low‐cost satellite earth stations, and then briefly to illustrate the design methodology that was adopted. Finally, it presents some of the experimental and theoretical results, which are in good agreement and demonstrate the performance achievable with this class of feeds.
Effective refractive index and single‐transverse mode condition in InGaAsP/InP BH laser diodes
Authors: Ghafoori‐Shiraz H. 
Published: July 2007

AbstractThe effective refractive index and single‐transverse mode condition in three‐layer BH laser diodes operating at 1.3 and 1.55 μm have been investigated for both TE and TM modes. The results can be useful in the design of laser diodes with improved light‐output coupling efficiency into single‐mode fibers and also to determine the corrugation period of DFB lasers.
Heterodyne detection of small angle scattered far‐infrared laser radiation
Authors: Jacobsson Stellan , Hård Sverker 
Published: July 2007

AbstractA heterodyne detection scheme for far‐infrared small angle scattered laser radiation is reported and demonstrated by measuring the known scattering from a thin wire scatterer. Frequency shifts were on the order of 10 Hz. A Golay cell was used as a detector. The results were compared with theoretical predictions and direct detection data. The method should be useful for scattering measurements of density waves in plasmas.
Computer‐aided design of nonlinear optimum output power mesfet oscillator
Authors: Choo E. B. L. , Stewart J. A. C. , Fusco V. F. 
Published: July 2007

AbstractLarge‐signal MESFET microwave oscillator design is a nontrivial problem, involving nonlinear analysis, or extensive and time consuming load‐pull methods. A computer‐aided oscillator design technique employing nonlinear analysis in conjunction with optimization to identify the device best operating condition, for maximum output power, is described. Experimental verification at Ku band is presented.
A high gain microstrip array adopting EMC dipoles
Authors: Russo P. , Ruggieri M. 
Published: July 2007

AbstractSamples of microstrip arrays for linear polarization have been developed for operating in the 11.7‐12.5‐GHz frequency range starting from analyses and experiments performed on EMC dipoles and corporate feed boards.The array analysis approach is discussed together with the results achieved. Further results, obtained for circularly polarized structures, are also presented.Attractive performance has been achieved, especially in terms of bandwidth and efficiency.
Self‐steepening effect of optical pulse propagating in kerr medium
Authors: Dingyuan Tang , Peixia Qiu , Fuxin Zhou , Runwen Wang 
Published: July 2007

AbstractUsing a specially designed liquid‐core optical fiber system and Q‐switched optical pulse, we have first experimentally observed the effect of self steepening of the optical pulse caused by the optical Kerr effect. The mechanism and characteristics of this effect have also been analyzed theoretically.
Finite‐element analysis of anisotropic waveguides with storage reduction and elimination of spurious modes
Authors: Pantic‐Tanner Zorica , Chan Chi Hou , Mittra Raj 
Published: July 2007

AbstractIn this paper we present a finite‐element analysis of waveguides that are inhomogeneously filled with an anisotropic material, which may be either dielectric or magnetic type. The problem is formulated by using the transverse magnetic or electric field components, respectively, for anisotropic dielectric and magnetic materials. The formulation employed eliminates the spurious and nonphysical modes by analytically satisfying the divergence relations and achieves a reduction in the computer storage requirement as well. Numerical results are found to exhibit good agreement with the available data.
A full‐wave solution for the mutual coupling between circular microstrip patch antennas
Authors: Aberle J. T. , Pozar D. M. 
Published: July 2007

AbstractA full‐wave solution for the mutual coupling between circular microstrip patches fed by idealized vertical probe feeds is presented. The grounded slab Green's function is used together with the moment method to determine the current distribution on each patch. From this, the patch port impedance matrix and, hence, the mutual coupling can be determined. Measured data that validate the theory are presented.
Cutoff frequencies and radial wave numbers of surface wave modes in a multilayered structure
Authors: Bhattacharyya Arun K. 
Published: July 2007

AbstractFormulations of radial wave numbers and cutoff frequencies for surface wave modes in a multilayered structure on a ground plane are presented Numerical results for one, two, and three layered structures are shown. These results will be useful for determining the existence of possible surface wave modes in a multilayered structure at a given frequency of operation.
Frequency chirping and the impact of 1/f‐type noise in negative electrical feedback semiconductor lasers
Authors: Jianping Zhang , Ling Li , Peida Ye 
Published: July 2007

AbstractIn this letter we will present a complete analysis of frequency chirping in negative electrical feedback (NEFB) semiconductor lasers by using the semiclassical rate equation model. The effects of 1/f‐type FM noise also will be discussed. Our result shows that this kind of noise is an important origin of the linewidth reduction limitation.
Spectral green's functions for a thin, circular, magnetic‐current loop for microstrip VIA hole analysis
Authors: Chan C. H. 
Published: July 2007

AbstractThe full‐wave spectral Green's function for a thin, circular, magnetic‐current loop radiating slightly above the shorted aperture of a microstrip via hole is given. The expression for the electric potential (in the spectral domain) due to the magnetic‐current loop is then derived for both the full‐wave and electrostatic cases.
Analysis and design of extracted pole E‐plane filters
Authors: Mansour R. R. , Fouladian J. 
Published: July 2007

AbstractThis paper presents a rigorous field theory analysis and design of a novel configuration for E‐plane filters. The proposed configuration is suitable for diplexer applications and preserves the desirable features of conventional E‐plane filters. The analysis is based on the mode matching technique, which allows the effect of the higher order modes to be taken into account in the optimization process. The numerical results agree well with the measured data.
Low impedance matching: The radial stub solution
Authors: Giannini F. , Ruggieri M. , Bartolucci G. , Paoloni C. 
Published: July 2007

AbstractThe radial stub as a key microstrip structure to provide low impedance levels with a well‐defined insertion point is proposed. Its characterization through a planar approach provides a superior accuracy, as compared with the simulations attainable from presently available CAD packages. Some experiments have fully confirmed the design. Furthermore, the flexibility of radial lines in replacing both open and shorted straight stubs is demonstrated together with some successful results, achieved through their use in practical applications.
X‐band local oscillator distribution network
Authors: Bharj Sarjit S. , Tan S. P. , Gluck J. , Thompson B. 
Published: July 2007

AbstractAn X‐band local oscillator network has been designed and developed to provide in excess of +8 dBm for four independent channels. The network consists of an X‐band voltage controlled oscillator tunable from 8 to 12 GHz. The output of the oscillator is input to a set of three MMIC in‐phase power splitters with 0 dB gain and excellent phase performance.
Optical implementation of A 2‐D neural net with a third‐order interconnection for image quadratic associative memory based on a compact‐encoding method
Authors: Lin Senmao , Wu Jie , Liu Liren 
Published: July 2007

AbstractThe optical implementations of a 2‐D neural net with a third‐order interconnection for image quadratic associative memory are reported. Two types of incoherent optical systems, based on multiple imaging and correlation, are used. In particular, a compact‐encoding method, which can greatly reduce the size of the interconnection tensor, is also proposed. The experimental results are given.
Double fsk coherent optical system exploiting the orthogonal polarization modes of a single‐mode fiber
Authors: Betti S. , Curti F. , de Marchis G. , Lannone E. 
Published: July 2007

AbstractA novel coherent optical system is proposed based on transmission of two FSK modulated signals associated to orthogonal polarization states of a single‐mode fiber. At the receiver the transmitted signals are separated by Jones matrix inversion providing insensitivity to polarization fluctuations and allowing the use of two semiconductor lasers at the transmitter.
Rigorous solutions of problems of electromagnetic resonators loaded with high‐loss dielectrics
Authors: Xu Yansheng , Bosisio Renato G. 
Published: July 2007

AbstractIn this paper, free oscillations in a rectangular cavity loaded with a high‐loss dielectric slab are analyzed and calculated. By means of the transformation of the complex characteristic equation into an ordinary differential equation and the application of suitable initial conditions, this problem is solved with both simplicity and high accuracy. The behavior of resonant frequencies (both the real and imaginary parts) of various modes is demonstrated and discussed. Our theoretical results will be helpful to computer simulation of heating and cooking processes in microwave ovens and applicators; our method of analysis may also be used in the calculation of microwave components and devices loaded with high‐loss dielectrics or magnetic materials.
Multifrequency antenna system for propagation experiments at 12.5, 20, and 30 GHZ
Authors: Herben M. H. A. J. , de Maagt P. J. I. , van de Goor W. A. , Casper A. C. A. 
Published: July 2007

AbstractA multifrequency antenna system for future propagation experiments, at 12.5, 20, and 30 GHz with the Olympus satellite, is described. This antenna system consists of a 5.5 m Cassegrain reflector antenna and a multifrequency feed system.
Addition to spectral domain analysis of a microstrip thin superconducting line laid on GaAs substrate
Authors: Huret F. , Kinowski D. , Pribetich P. , Kennis P. 
Published: July 2007

AbstractOur letter was published in the June, 1989 issue.* We would like to add additional curves to this letter in order to clarify the curves exhibited on Figure 4 with a too extensive caption. Furthermore, some mistakes have been introduced in the curves due to this bad representation. But the main purpose of this addition is to make some comments on the determination of σ1 and σ2 for new high Tc superconductor YBaCuO, especially for thin film.
A technique for reducing mutual coupling between rectangular microstrip antennas by frequency scaling
Authors: Gupta B. , Chaudhuri S. R. Bhadra , Mukherjee A. , Poddar D. R. , Chowdhury S. K. 
Published: July 2007

AbstractA significant reduction of mutual coupling between E‐plane coupled rectangular microstrip antennas by frequency scaling is presented. Compactness in the design may also be achieved by this technique.
Parameters of shielded modified coupled microstrip lines
Authors: Hanna Victor Fouad 
Published: July 2007

AbstractAnalytic closed‐form expressions for even‐ and odd‐mode characteristic impedance and effective dielectric constant for shielded coupled microstrip lines, either having or not having a tuning slit in their back metallization, are obtained using conformal mapping techniques. The effect of the existence of this tuning slit as well as that of the upper shielding is studied.
Theoretical investigation on the effects of nonmatching loads upon the impedances of millimeter wave oscillators
Authors: Hong Wei 
Published: July 2007

AbstractIn this paper the effects of nonmatching loads on the impedances of millimeter wave oscillators are analyzed. For a special case of matching load, the numerical results are in agreement with Doring's experimental data and Wu's theoretical results. The impedance variations due to the nonmatching loads are first presented and some useful conclusions are followed.
Millimeter‐wave detection using resonant tunnelling diodes
Authors: Mehdi I. , Kidner C. , East J. R. , Haddad G. I. 
Published: July 2007

AbstractA lattice‐matched InGaAs/InAlAs resonant tunnelling diode is studied as a video detector in the millimeter‐wave range. Tangential signal sensitivity and video resistance measurements are made as a function of bias and frequency. A tangential signal sensitivity of — 37 dBm (1 MHz amplifier bandwidth) with a corresponding video resistance of 350 Ω at 40 GHz has been measured. These results, to the best of our knowledge, are the first millimeter‐wave tangential signal sensitivity and video resistance results for a resonant tunnelling diode.
Complex permittivity of lanthanum aluminate in the 20 to 300 K temperature range from 26.5 TO 40.0 GHZ
Authors: Miranda F. A. , Gordon W. L. , Bhasin K. B. , Ebihara B. T. , Heinen V. O. , Chorey C. M. 
Published: July 2007

AbstractDielectric constants of microwave subtrales are required in the design of superconducting microwave circuits at various temperatures. In this paper, we report the results of a study of the complex permittivity of the newly developed lanthanum aluminate (LaAIO3) substrate, in the 20 to 300 K temperature range at frequencies from 26.5 to 40.0 GHz. The value of the complex permittivity was obtained by measuring the sample scattering parameters using a microwave waveguide technique. It is observed that, while the dielectric constant did not change appreciably with frequency, its value decreased by approximately 14 percent from room temperature to 20 K.
Total reflected millimeter‐wave power from moving‐strip‐illuminated semiconductor panel
Authors: Rahnavard M. H. , Habibzadeh A. 
Published: July 2007

AbstractMoving‐spot‐illuminated semiconductor panels are used as millimeter‐wave image converters. To determine the performance of this system, it is required to know the response of illuminated semiconductor panels. In this paper total reflected' millimeter power from moving‐strip‐illuminated semiconductor panels as a function of attenuation, scanning velocity, width of the strip, etc., is studied.
Active devices for microwave distributed amplification
Authors: D'Inzeo Guglielmo , Giusto Roberto , Petrachi Claudio 
Published: July 2007

AbstractThe theoretical results presented in this letter demonstrate the possibility of growing waves' propagation along MESFET electrodes, through a distributed interaction mechanism based on the active characteristics of the transistor. The analysis proves that a T cross‐section gate is necessary to obtain amplification, moreover this gate configuration allows a remarkable reduction of the electrode gate resistance. In the validity range of the analysis used, the main feature of the new device is a wide bandwidth, deriving from a fully distributed component. This device could result in a valid substitute for low power TWTs.
Multidomain gunn diodes
Authors: Tsay Jenngang , Schwarz S. E. , Raman Shankar , Smith J. S. 
Published: July 2007

AbstractA technique for obtaining multidomain operation of Gunn diodes is proposed. Device impedance is increased, leading to large potential increases in output power. The precision required of the doping profile has been estimated by simulation and appears to be within the capabilities of molecular beam epitaxy. Estimates of output power, taking thermal effects into account, indicate that in many cases an N‐domain diode can produce N2 times as much power as a single‐domain diode. For example, it should be possible to obtain 1.8 W from a three‐domain device oscillating at 30 GHz.
Performance of convolutional codes in noisy optical channels using an APD‐viterbi decoder receiver
Authors: Fares Doaa A. 
Published: July 2007

AbstractIn this analysis, performance evaluation of orthogonal convolutional coded pulse position modulation (PPM) in a typical binary‐asymmetric optical channel is presented. Then, the system performance is compared to that of the Reed‐Solomon coded PPM model, where high background noise affects the channel behavior. Using an avalanche photodetector for detection, threshold decision technique is used. This treatment for the PPM orthogonal convolutional coding is more comprehensive than that described in reference 1.
Broadband design of ring type microstrip power divider
Authors: Roy Jibendu Sekhar , Poddar Dipak Ranjan , Chowdhury Santosh Kumar 
Published: July 2007

AbstractThe broadband design of a ring type microstrip power divider with any desired power division ratio is described. The improvement in bandwidth is obtained by the addition of a fifth port to the conventional four‐port power divider design. The present design provides good device performance over a wide range of frequency. For a minimum isolation of around 30 dB, the coupling coefficients remain about constant over a band of frequency that is 30% of the design center frequency. This design technique is applicable to both equal and unequal power divisions. This broadband design of power divider is very useful for the basic power divider of the feeding network in microstrip antenna arrays including phased arrays.
Performance evaluation of two passive mmic components
Authors: Choudhury Debabani , Mahapatra S. 
Published: July 2007

AbstractAn important part of the monolithic microwave integrated circuits (MMICs) are the passive circuit elements which outnumber the FETs. In this article, design procedures and techniques for realizations of two passive components (viz., power divider and interdigital capacitor) on the semiinsulating GaAs substrates are indicated. Performances of the components are described and commented on.
A novel very wideband 2‐port S‐parameter calibration technique
Authors: Soares R. , Gouzien P. , Meszaros S. 
Published: July 2007

AbstractIn this article explicit formulas are presented permitting the de‐embedding of two‐port S‐parameter data in the case of the through‐reflect family of calibration techniques. The readily programmable algorithm developed is applied to a novel through‐attenuate‐reflect method (TAR) which, unlike the through‐reflect‐line method, has no inherent bandwidth limitation.
Effect of a parasitic mode on the performance of a serpentine waveguide mode converter
Authors: Kasraian Masoud , Seshadri S. R. 
Published: July 2007

AbstractA cylindrical waveguide with an axis having a weak harmonic variation about a straight line in a plane can be used to convert selectively the TEpq mode to the TEp+1,r mode. The performance of this waveguide converter in the presence of a parasitic mode is examined and certain aspects of the optimization of this distributed mode converter are discussed.
A derivation of the vector addition theorem
Authors: Chew W. C. 
Published: July 2007

AbstractAn alternative derivation of the vector addition theorem is presented using the completeness of vector wave functions and integration by parts. The advantage of this derivation is that it leads directly to the simplified results of Bruning and Lo and of Stein. Moreover, the dichotomous results of the addition theorem when a spherical Hankel function is involved can be derived by contour integration.
Space‐variant aberrations: Differential operator
Authors: Ojeda‐Castañeda J. , Ibarra J. 
Published: July 2007

AbstractA differential operator describes the influence of space‐variant aberrations on a diffraction‐limited image, formed under coherent illumination. To illustrate our general treatment, the Talbot effect for space‐variant defocus is discussed in terms of the eigenfunctions of the differential operator.
Dielectric properties measurement of substrate and support materials
Authors: Wu Te‐Kao 
Published: July 2007

AbstractIn this paper a fast and straightforward waveguide measurement technique is described for the determination of the dielectric constant and loss tangent of many commercially available materials. These dielectric materials include Cuflon, Teflon, Arlon's polyimides, Lockheed's ceramic foams, and Rogers Duroid materials. The effective dielectric constant and loss tangent of Hexsel's honeycomb material is also measured by this method and is compared to the predicted data obtained using the volume averaging theory. The accuracy and other features of this measurement technique are also discussed.