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Showing papers by "University of Electronic Science and Technology of China published in 1992"


Journal ArticleDOI
TL;DR: In this paper, the effect of the reduction of the peak field at the edges of reverse-biased p-n junctions by the resistive field plate (RFP) and variation lateral doping (VLD) is explained with the surface charges induced by their structures.
Abstract: The effect of the reduction of the peak field at the edges of reverse-biased p-n junctions by the resistive field plate (RFP) and variation lateral doping (VLD) is explained with the surface charges induced by their structures. Analytical solutions of the field profile under the RFP and under the VLD were found, from which the optimum doping profile of the VLD can also be found. The relations between the breakdown voltage and the surface depletion width for these two structures are proposed. The realization of the optimum VLD by an approach using multiple zones of the JTE is proved to be satisfactory.

53 citations


Journal ArticleDOI
TL;DR: The atom percentage of an optical compound film coated with Ta 2 O 5, ZrO 2 and TiO 2 materials using a double e-gun is measured and calculated in this paper.

12 citations


Journal ArticleDOI
01 Aug 1992-Vacuum
TL;DR: In this paper, bias voltage treatment and vacuum annealing was applied to indium tin oxide (ITO) films to obtain a resistivity of 3 × 10 −4 Ω·cm and transmittance better than 85% in the visible spectrum.

9 citations


Journal Article
TL;DR: In this paper, the analysis of electromagnetic propagation and scattering from axially symmetrical, two dimension-layered media with arbitriry N planar layers in virtical direction and cylindrical layers in radial direction has been made.
Abstract: In this paper the analysis of electromagnetic propagation and scattering from axially symmetrical, two dimension-layered media with arbitriry N planar layers in virtical direction and cylindrical layers in radial direction has been made. The numerical mode matching (NMM) theory is used to simplify computation. In this method the discrete numerical eigenmodes are used in radial direction and the mode matching method is used in virtical direction to derive the recurrent expresions of the field. This half-analytical and half-numerical method avoids tremendous computation of two dimensions as in Finite element method (FEM). The subsurface electrical parameter profile can be rebuilt by using the numerical results of the field. Counting for inference of various factors in the subsurface formation, this method can be used as computer aid explaination tool for induced logging and deep propagation logging tool (DPT).

9 citations


Journal ArticleDOI
TL;DR: In this article, the effect of imperfectly conducting surface of scatter on the radar cross-section of a cylinder with absorbent materials is studied, and the relationship between σ/λ2 and λs is obtained.
Abstract: The scale-down model testing of radar cross section for imperfectly conducting bodies requires physical similarity between models and prototype. Practically, it is often impossible to satisfy all the requirements at the same time; so it is necessary to study the effect of imperfectly conducting surface of scatter on its RCS. Dimensional analysis and theory of the model are used. As a result, relationship between σ/λ2 and λs is obtained, and the comparison between theoretical and experimental values for a cylinder coated with absorbent materials is given.

8 citations


Journal ArticleDOI
TL;DR: In this article, the scale factor of RCS for lossy targets is given, by which the RCS of a complex lossy target can be calculated in terms of scale-model testing, even though the model does not satisfy similarity becausse of coated absorbent materials.
Abstract: In this article the scale factor of RCS for lossy targets is given, by which the RCS of a complex lossy target can be calculated in terms of scale-model testing, even though the model does not satisfy similarity becausse of coated absorbent materials. © 1992 John Wiley & Sons, Inc.

6 citations


Proceedings ArticleDOI
01 Jun 1992
TL;DR: In this paper, a coherent CO2 laser system is described, where the master laser is stabilized over its tuning range by NH2D Stark cell and the local laser is offset frequency-locked by an electric loop.
Abstract: This paper describes a coherent CO2 laser system. The master laser is stabilized over its tuning range by NH2D Stark cell and the local laser is offset frequency-locked by an electric loop. Error signal produced by NH2D Stark cell is analyzed and the phase fluctuation of the heterodyne signal due to noises is discussed. A 23Hz Allan variance for the beating signal between laser beams has been achieved at 1 s gate time.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

6 citations


Journal ArticleDOI
TL;DR: In this article, the electromagnetic radiation of arbitrarily oriented elementary dipole sources, both electric and magnetic types, embedded in stratified chiral media is investigated using the matrix analysis, in conjunction with the Fourier transformation techniques for the observation points not near the excited sources.
Abstract: EM radiation of the arbitrarily oriented elementary dipole sources, both electric and magnetic types, embedded in stratified chiral media is investigated using the matrix analysis, in conjunction with the Fourier transformation techniques for the observation points not near the excited sources.

6 citations


Journal ArticleDOI
TL;DR: In this paper, the general volume equivalence theorem for bianisotropic scatterers is presented, where the equivalent electric and magnetic currents are determined by a pair of coupled vector integral equations.
Abstract: The general volume equivalence theorem for bianisotropic scatterers is presented, where the equivalent electric and magnetic currents are determined by a pair of coupled vector integral equations. Moreover, using the general volume equivalence theorem and conventional image principle, image theory is developed for a bianisotropic body over an infinite perfect electric or magnetic conducting ground plane.

5 citations


Journal ArticleDOI
TL;DR: The fabrication and properties of the multilayer Sr0.7Ba0.3TiO3 ceramic varistors made from low-fire ceramic materials doped with small amounts of additives such as Nb2O5 and Li2CO3 are described in this article.
Abstract: The fabrication and properties of the multilayer Sr0.7Ba0.3TiO3 ceramic varistors made from low-fire Sr0.7Ba0.3TiO3-based ceramic materials doped with small amounts of additives such as Nb2O5 and Li2CO3 are described. After being sintered at 1100° C in a reducing atmosphere and annealed at 900° C in air, the varistors exhibited the following characteristics: varistor voltage V1mA, 10 v; nonlinear coefficientα, 15. The varistor voltage was almost unchanged against a supplied surge energy of 300 J/cm3. The varistors had excellent capacitor characteristics. The capacitance and loss factor were 80 nF and 2%, respectively.

5 citations


Proceedings ArticleDOI
10 May 1992
TL;DR: A recursion-adaptive nonlinear filter structure that is based on the linear combination of order statistics is developed, using the minimal mean square error (MSE) criterion and the unbiasedness condition, and two efficient methods to update the filter coefficients are presented.
Abstract: A recursion-adaptive nonlinear filter structure that is based on the linear combination of order statistics is developed, using the minimal mean square error (MSE) criterion and the unbiasedness condition, Two efficient methods to update the filter coefficients are presented. The proposed recursion algorithms can adapt well to a variety of noise probability distributions and are useful for real-time applications. The MSE estimation computed using the local statistics of the input signal and noise is considered. Simulation results on one-dimensional signals and real images are also presented. >

Journal ArticleDOI
TL;DR: In this paper, the scattering response of an electrically small bianisotropic particle suspended in free space is studied, and it is found that cross-polarization and/or copolarisation phenomena may occur for certain constitutive relations, separatively.
Abstract: Scattering response of an electrically small bianisotropic particle suspended in free space is presented. Formulation of this problem is based on the assumption that the electrical small bianisotropic particle can be modelled as both an equivalent electric and a magnetic dipole moments. It is found that cross-polarization and/or co-polarization phenomena may occur for certain constitutive relations, separatively.

Journal ArticleDOI
TL;DR: In this paper, a detailed analysis of the higher harmonic in free electron laser (FEL) with combined electromagnetic wiggler and axial guide magnetic fields is derived, and the spontaneous emission spectrum and the gain in the low-gain Compton regime are also calculated in detail.
Abstract: Following a single-particle approach, a detailed analysis of the higher harmonic in free electron laser (FEL) with combined electromagnetic wiggler and axial guide magnetic fields is derived. The spontaneous emission spectrum and the gain in the low-gain Compton regime are also calculated in detail. This analysis results in a clear resonance condition and shows that this kind of FEL can generate significant coherent harmonic emission of radiation with axial guide magnetic field of suitable strength.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the radiation of an electric dipole located along an arbitrary direction in the presence of a grounded chiral slab using matrix analysis in conjunction with Fourier transform techniques.
Abstract: Radiation of an electric dipole located along an arbitrary direction in the presence of a grounded chiral slab is investigated using matrix analysis in conjunction with Fourier-transform techniques. Numerical results of the radiation pattern of such a structure are plotted both for vertical and parallel cases.

Journal ArticleDOI
TL;DR: In this paper, a systematic approach is presented for finding the resonant frequency, damping factor and EM field distribution of a layered planar structure consisting of chiral media and having arbitrary conductor sheets at the interfaces.
Abstract: In this paper, a systematic approach is presented for finding the resonant frequency, damping factor and EM field distribution of a layered planar structure consisting of chiral media and having arbitrary conductor sheets at the interfaces. The analysis is based on the spectral dyadic Green's function followed by a Ritz-Galerkin's process, using matrix analysis in the Fourier transform spectral domain. The great value of our formulation lies in that it provides methodology for the solutions to chiral layered media problems.


Journal ArticleDOI
TL;DR: In this paper, a bandpass filter with all-metal insert, an inductive strip in the E-plane of a waveguide is analyzed by a prototype filter and the scattering matrix of the strip is calculated by electromagnetic fields theory theoretically.
Abstract: In this paper, a bandpass filter with all-metal insert, an inductive strip in the E-plane of a waveguide is analyzed by a prototype filter and the scattering matrix of the strip is calculated by electromagnetic fields theory theoretically. By means of matrix combining technique, the scattering matrix of a bandpass filter of this type is obtained. And a rigourous error function is used to optimize the CAD program by Powell's method and make the experimental results agree well with the theory design at V-band.

Journal ArticleDOI
TL;DR: In this article, an infinitely long bianisotropic cylinder with electrically small cross-section suspended in free space is presented, and a coupled integral equation method with the long wavelength approximation is proposed.
Abstract: EM scattering response of an infinitely long bianisotropic cylinder with electrically small cross-section suspended in free space is presented. Formulation of this problem is based on the coupled integral equation method with the long wavelength approximation. Reduced expressions for the scattering of plane waves, both E-wave and H-wave types, are obtained. It is revealed that for certain polarization matrices determined by the constitutive parameters of the scatterer, cross-polarization and/or co-polarization phenomena may occur, respectively.


Journal ArticleDOI
TL;DR: In this article, a new formulation for coherent inelastic scattering by an arbitrary body uniformly filled with active molecules was obtained by the extended boundary condition method and a particular solution of the nonhomogeneous wave equation for the inelastically electric field inside the body due to the existence of active molecules is included.
Abstract: A new formulation for coherent inelastic scattering by an arbitrary body uniformly filled with active molecules is obtained by the extended boundary condition method and a particular solution of the nonhomogeneous wave equation for the inelastic electric field inside the body due to the existence of active molecules is included. The agreement between the current results for coherent inelastic scattering by a sphere uniformly filled with active molecules and the exact resuits shows the current formulation is not restricted to the case of weak scattering. © 1992 John Wiley & Sons, Inc.

Journal ArticleDOI
TL;DR: In this article, the authors reformulate Riblet's results with some comments and give an excellent treatment of this rectangular line with an off-center strip inner conductor, which may not be very useful to those not very familiar with elliptical integrals.
Abstract: In 1979 Riblet gave an excellent treatment of this rectangular line with an off-center strip inner conductor [1]; however this work may not be very useful to those not very familiar with elliptical integrals. Here we will try to reformulate Riblet's results with some comments.

Proceedings ArticleDOI
09 Jun 1992
TL;DR: The physical models of the phase control of different phased errors in SAS are presented, and a computer simulation of the beams control in SAS is performed via the FFT computational methods.
Abstract: The effects of phased errors, such as piston errors, tilt errors, and focus errors, on beams combination in synthetic aperture systems (SAS) are analyzed based on the experiments conducted by Hu Zhiping et al. (1989, 1990) on beam control of SAS in vacuum and on a numerical simulation. The physical models of the phase control of different phased errors in SAS are presented, and a computer simulation of the beams control in SAS is performed via the FFT computational methods. The result are presented in form of three-dimensional graphs.

Proceedings ArticleDOI
09 Jun 1992
TL;DR: In this article, a 10.6-micron laser heterodyne receiving system with acoustooptic frequency modulation is described, where first-order diffraction beams are used as the optical signal modulation beam in the transmitting optical terminal, a 77 K-PV-HgCdTe detector is used as heterodyn reception device in the receiving optical teminal, and the Stark cells are used in the transmission and reception terminals in order to stabilize the frequencies of local and signal laser.
Abstract: A 10.6-micron laser heterodyne receiving system with acoustooptic frequency modulation is described. In this system, the first-order diffraction beams are used as the optical signal modulation beam in the transmitting optical terminal, a 77 K-PV-HgCdTe detector is used as heterodyne reception device in the receiving optical teminal, and the Stark cells are used in the transmission and reception terminals in order to stabilize the frequencies of local and signal laser. With the application of frequency shift key digital modulation, the terminal bit error rate is better than 10 exp -8.

Journal ArticleDOI
TL;DR: In this paper, the authors derived the gain formula of the ICL with slab geometry in the low gain using the madey's theorem, which is a valuable guide in research with new types of FEL's.
Abstract: Ion-Channel Laser (ICL) is a new form of laser, which can produce tunable coherent radiation with frequencies ranging from microwaves to soft X-rays. In this paper, the ICL with slab geometry in the low gain is studied. Using the Madey's theorem, the gain formula of the ICL is derived. The result shows that the Madey's theorem is a valuable guide in research with new types of FEL's.

Proceedings ArticleDOI
09 Jun 1992
TL;DR: In this paper, the effect of Doppler broadening on the Stark bistability of a (C-13)(O-16)2 laser has been investigated using the interaction between the asQ(6,6) transitions in NH3 gas and the R(18) line of the laser.
Abstract: This paper reports observations of a Stark tunable bistable optical device (BOD) (Smith et al., 1977) which uses the interaction between the asQ(6,6) transitions in NH3 gas and the R(18) line of a (C-13)(O-16)2 laser. It is shown that optical bistability can be observed using this laser as the nonlinear element. The effect of Doppler broadening on the Stark bistability is shown via numerical calculations. The observed effect is consistent with results of the theoretical analysis.

Journal ArticleDOI
TL;DR: In this article, the interaction between electron beam and RF fields of H811 π-mode in an eighth harmonic cusptron at f0=35GHz was studied numerically.
Abstract: The interaction between electron beam and RF fields of H811 π-mode in an eighth harmonic cusptron at f0=35GHz is studied numerically. The finite thickness and eccentricity of a rotating annular electron beam and the cusp magnetic field in the imbalance case (Bc≠−B0) are considered in the mumerical calculation. The results show that these pratical factors have a great influence upon the electron efficieency.

Journal ArticleDOI
TL;DR: In this article, the k-exponential stability of non-linear delay systems is investigated via the nonlinear variation of parameters formula and nonlinear inequality analysis, and a new concept of k-Exponential stability is introduced.
Abstract: In this paper we introduce a new concept of k-exponential stability. The k-exponential stability of non-linear delay systems is investigated via the non-linear variation of parameters formula and non-linear inequality analysis.

Journal ArticleDOI
TL;DR: In this paper, a 4-pair target-facing-type sputtering method was used to prepare magneto-optical (MO) TbFeCo films and the results showed that the targets sputtering current and substrate temperature have great influence on the microstructure of the Tb FeCo films.

Journal ArticleDOI
TL;DR: The stability control model of asymmetric unstable networks is suggested, which is also a valid way for optimization and dynamic control of stable neural networks.
Abstract: A new method for analyzing dynamics of continuous neural networks is proposed, and the necessary convergence conditions for a class of associative networks are obtained. Based on the stability criterion and the equations of equilibrium set of the network, synthesis of a class of associative neural networks is given. The stability control model of asymmetric unstable networks is suggested, which is also a valid way for optimization and dynamic control of stable neural networks.

Journal ArticleDOI
TL;DR: In this article, the analysis method for the antipodal finline waveguide-to-micro-strip transition is presented, and the experimental results have a good agreement with the theoretical ones.
Abstract: The analysis method for the antipodal finline waveguide-to-micro-strip transition is presented in the article. The revised empirical expressions for the transition from nonoverlapped antipodal finline to overlapped one are given. We design a Ka-band broadband waveguide-to-microstrip transition using this method. The experimental results have a good agreement with the theoretical ones.