Showing papers by "University of Electronic Science and Technology of China published in 1995"
TL;DR: In this paper, a sufficient condition for generalized diagonally dominant matrices was obtained under the assumption that A ∈ Cn,n is weakly diagonal dominant.
38 citations
TL;DR: It is shown that when an upper bound of the plant transfer function's H/sup /spl infin//-norm has been supplied, and the noise contaminating the time domain identification experiment data is not too significant, such a transfer function set can be parameterized by a linear fractional transformation of two transfer function matrices.
Abstract: In this paper, we investigate the structure of the transfer function set which includes all the transfer functions deduced from the plant available information. It is shown that when an upper bound of the plant transfer function's H/sup /spl infin//-norm has been supplied, and the noise contaminating the time domain identification experiment data is not too significant, such a transfer function set can be parameterized by a linear fractional transformation of two transfer function matrices. One of them is a fixed transfer function matrix which is completely determined by the plant available information and the noise magnitude. The other is a norm bounded, structure fixed, free transfer function matrix. Moreover, it is shown that the problem of analytically obtaining the fixed complexity nominal model that best approximates this transfer function set is as difficult as the /spl mu/-synthesis problem. >
35 citations
TL;DR: In this paper, a general proof of unification between two concepts of radar target angular glint was provided, and the analysis of a two-point target model, consisting of an electrically and magnetically ideal dipole, showed the relation, difference, and equivalent condition between them more clearly.
Abstract: This paper provides a general proof of unification between two concepts of radar target angular glint. The analysis of a two-point target model, consisting of an electrically and magnetically ideal dipole, shows the relation, difference, and equivalent condition between them more clearly. Angular glint has been synthesized from the measured data of radar echo phase, and compared with the theoretical result. >
22 citations
TL;DR: In this paper, the authors used the model T = ∝02π ∝0R E(r) cosn (θ) r/c2 dr dφ to calculate the film thickness distribution in a symmetrical magnet magnetron sputtering system.
17 citations
TL;DR: In this article, a numerical study of the TM01-TE11 circular waveguide mode converter, with its optimized size and structure, is presented, where many factors such as spurious modes, backward wave, perturbation functions of waveguide axis or radius, phase-rematching techniques and ohmic losses are taken into account for the influence to mode converter's efficiency and bandwidth.
Abstract: A numerical study of TM01-TE11 circular waveguide mode converter, with its optimized size and structure, is presented in this paper. Many factors such as spurious modes, backward wave, perturbation functions of waveguide axis or radius, phase-rematching techniques and ohmic losses are taken into account for the influence to mode converter's efficiency and bandwidth. And the dimensions of an optimized model (f0=35GHz. with input and output radius a0=13.6mm) are given.
17 citations
TL;DR: In this paper, the structure and magneto-optical properties of fine-grain garnet thin films crystallized by the Rapid Recurrent Thermal Annealing (RRTA) method have been studied.
15 citations
TL;DR: Numerical results show that the solution in terms of wave functions of various kinds in anisotropic media gives essentially the same radar cross sections as obtained by Beker, Umashankar, and Taflove using a different approach.
Abstract: The general solutions of the first, second, third, and fourth kinds to the wave equation in homogeneous anisotropic media are expressed by integrals over a finite range. The convergence of the series solution of wave functions in homogeneous anisotropic media [Phys. Rev. E 47, 664 (1993)] is discussed. The use of the wave functions in anisotropic media is demonstrated. The theory is expounded via an illustrative example of a two-dimensional scalar case. The analytical solution of plane-wave scattering by a conducting circular cylinder coated with anisotropic materials is formulated in terms of the series of wave functions for anisotropic media. Numerical results show that the solution in terms of wave functions of various kinds in anisotropic media gives essentially the same radar cross sections as obtained by Beker, Umashankar, and Taflove [Electromagnetics 10, 387 (1990)] using a different approach. Numerical results in the resonance region are presented for reference purposes. The analysis of this paper can be easily generalized to vector and tensor wave functions in homogeneous anisotropic media.
15 citations
TL;DR: In this paper, a new complex source representation for time harmonic radiation from a plane aperture is proposed, which is the Kirchhoff's spatial convolution formula of a complex plane aperture with the complex aperture field being the analytic extension of the original aperture field.
Abstract: Developed here is a new complex source representation for time harmonic radiation from a plane aperture which is the Kirchhoff's spatial convolution formula of a complex plane aperture with the complex aperture field being the analytic extension of the original aperture field. A systematic study for a one-dimensional linearly phased cosine aperture distribution confirms the effectiveness of the new method in the simulation of the time harmonic radiation. >
14 citations
TL;DR: In this paper, rapid thermal annealing was used to crystallize a glass/Al/BiGaDyIG double-layer film, where Bi-Dy-IG denotes dysprosium iron garnet films doped with Bi and Ga.
Abstract: The rapid thermal annealing method is used to crystallize a glass/Al/BiGaDyIG double-layer film (where BiGaDyIG denotes dysprosium iron garnet films doped with Bi and Ga); the effective Faraday angle of the double-layer film is about 0.25° greater than that for glass/BiGaDyIG film and about 0.15° greater than that for common glass/BiGaDyIG/Al double films in a wide thickness range; meanwhile the Curie point is decreased because of the aluminium atoms diffusing into the garnet film and substituting at octahedral and tetrahedral Fe 3+ sites. The Curie temperature can be adjusted between 161 and 140 °C by means of delay annealing duration. The grain diameter and Faraday angle as functions of heating rate α and number of rapid recurrent annealings N have been presented, and are used to explain the mechanism of effective Faraday angle increase and grain size decrease, suggesting that glass/Al/BiGaDyIG films are promising candidates for blue light magneto-optical recording disks.
11 citations
TL;DR: A new spectrum estimation method for direction-finding, the FOMUSIC algorithm, which is based on the eigen-structure analysis of the fourth-order cumulants, which outperforms the traditional methods, especially when the noise is an unknown colored one.
Abstract: Traditional approaches of spatial spectral estimation are usually based on the second-order statistics. The higher-order cumulants and the poly-spectrum contain more information and are capable of reducing the Gaussian noise. In this paper, we present a new spectrum estimation method for direction-finding, the FOMUSIC algorithm, which is based on the eigen-structure analysis of the fourth-order cumulants. The derivation of the algorithm is given in detail and its performance is illustrated by both the computer simulations and the experiments of a direction-finding system. The obtained results demonstrate that the fourth-order cumulants based method outperforms the traditional methods, especially when the noise is an unknown colored one.
10 citations
TL;DR: In this paper, an analytical solution of plane-wave scattering by an anisotropic circular cylinder is given in terms of the wave functions for an isotropic media, and the T matrix of the T-matrix of a circular cylinder has been derived.
Abstract: An analytical solution of plane-wave scattering by an anisotropic circular cylinder is given in terms of the wave functions for anisotropic media. The T matrix of an anisotropic circular cylinder is derived. Numerical results in the low-frequency range are used to check our calculations, and those in the resonance region are also presented.
TL;DR: In this paper, the properties of fuzzy finite-state automaton languages are studied, i.e. under the operators of union, concatenation and closure, fuzzy finite, state-of-the-art automata are close.
TL;DR: In this article, a whispering gallery mode ring dielectric resonator was proposed and the theoretical analysis and a method for determination of the resonant frequencies was presented by the mode matching method.
Abstract: A new type of whispering-gallery mode ring dielectric resonators are first proposed. Theoretical analysis and a method for determination of the resonant frequencies is presented by the mode matching method. The numerical results show good agreement with theoretical analysis.
TL;DR: In this article, the degenerated rotational bipolar coordinate approach was used to solve the problem of point charge in front of a dielectric sphere in the plane interface between two different dielectrics.
TL;DR: The method of differential-Thompson transformation (DTTR) is applied for the first time to the field of electromagnetic scattering and the finite-difference-Time-Domain (FDTD) technique, the field distribution is solved conveniently.
Abstract: The method of differential-Thompson transformation (DTTR) is applied for the first time to the field of electromagnetic scattering. Complex objects and their computational areas are transformed by DTTR to a regular area. By applying the finite-difference-Time-Domain (FDTD) technique, the field distribution is solved conveniently. Numerical examples show good comparison with exact results. © 1995 John Wiley & Sons, Inc.
TL;DR: In this article, the authors presented the general formula of complex Huygens' principle, i.e., the complex point source representation of three-dimensional wave propagation, and derived the analytic formula of the strength of complex point sources for the special case that wave sources are enclosed in a sphere.
Abstract: Complex Huygens' principle provides an exact base for the simulation of wave propagation through a complex medium by complex ray. In this article, presented is the general formula of complex Huygens' principle, i. e. the complex point source representation of three-dimensional wave propagation, and the analytic formula of the strength of complex point source is derived here for the special case that wave sources are enclosed in a sphere.
TL;DR: In this article, an analysis and optimum method of a microstrip probe is presented, where the input impedance is derived through the dyadic Green's function in a dielectric loaded waveguide.
Abstract: An analysis and optimum method of a microstrip probe is presented. The input impedance is derived through the dyadic Green's function in a dielectric loaded waveguide. A wideband impedance match optimum process is employed to realize good return loss and insert loss of the microstrip probe. A Ka-band microstrip probe has been designed and tested. Experiment shows good coupling efficiency and return loss. © 1995 John Wiley & Sons, Inc.
TL;DR: In this paper, the reliability of a GI/G/I queueing system with a repairable service station was studied. But the reliability quantities of the service station were not considered.
TL;DR: In this article, a general representation of physical scale factor of RCS for variance in the size of simply shaped scatterers is described. But the results of this method from the model-testing agree well with their measured values both for two kinds of simply-shaped scatterer, cylinders and laddershaped plates.
Abstract: According to a general representation of physical scale factor of RCS for variance in the size of simply shaped scatterers, a novel RCS model-testing method is described. The computed results of the prototype scatterers by this method from the model-testing agree well with their measured values both for two kinds of simply shaped scatterers, cylinders and laddershaped plates.
Journal Article•
TL;DR: Progressive version switching TV and HDTVint could be reconstructed using one frame memory without the problems of handling temporal-vertical diamond shaped spectra of conventional TV andHDTVint based on one-frame memory algorithm in the receiver.
TL;DR: In this paper, the quasistatic parameters of coplanar strips and modified coplanars on a finitely thick substrate were derived through analyzing the structure with the complementary electrodes on the same substrate.
Abstract: Analytical expressions for calculating the quasistatic parameters of coplanar strips and modified coplanar strips on a finitely thick substrate were derived through analyzing the structure with the complementary electrodes on the same substrate [1, 2]. In this Letter we use conformal mapping techniques to investigate the accuracy of these expressions.
TL;DR: A threshold is derived and adopted to detect the number of orthogonalization in the procedure of Gram-Schmidt (GS) orthogonization decomposition, and this detection approach is simpler and faster than the approach based on eigenanalysis.
Abstract: Gram-Schmidt orthogonalization algorithm is an interesting theme in the field of adaptive beam-forming and filtering as a fast algorithm. However, a key problem associated with this algorithm is that the number of orthogonalization, namely, the dimensions of interference subspace, is required to know prior. In this paper we derive a threshold and adopt it to detect the number of orthogonalization in the procedure of Gram-Schmidt (GS) orthogonalization decomposition, and this detection approach is simpler and faster than the approach based on eigenanalysis. Finally, computer simulation results were presented too.
TL;DR: In this article, the general theory of syntopogenous structures on completely distributive lattices is established and the unified question of cotopology, quasi-uniformity and T-structure is investigated.
TL;DR: In this paper, a partially filled waveguide is presented to measure complex permittivity and permeability simultaneously at microwave frequency, and the mode-matching method is used to analyze the higher-order modes in the waveguide.
Abstract: A partially filled waveguide is presented to measure complex permittivity and permeability simultaneously at microwave frequency in this article. The mode-matching method is used to analyze the higher-order modes in the waveguide. Experimental results agree well with theoretical results. © 1995 John Wiley & Sons, Inc.
TL;DR: In this paper, an analytic method of the eguivalent network for RF sapphire window of 3mm diffraction radiation oscillator is given in a numerical simulation and experiment on 3mm wave band.
Abstract: A analytic method of the eguivalent network for RF sapphire window of 3mm diffraction radiation oscillator is given in the paper. Numerical simulate and experiment are carried out on 3mm wave band. The testing results show that the design method agrees with the practical windows, and it is the fast optimum method. We employ the universal method, the piece of the window can be equal to dielectric waveguide and one end of the window connects the coupling slit of the mirror of open cavity. The design window by means of this method is used satisfactorily on 3mm DRO. The tube operates in the 84 – 108GHZ band, the output power is about 250mW.
TL;DR: In this paper, the large amplitude nonlinear perturbed plasma electron density wave (wake wave) excited by an ultrarelativistic driving electron beam with finite length was used to upshift the frequency of the injected laser pulse behind the driving beam.
TL;DR: In this article, a technique for measuring the linearity of a linearly frequency-modulated continuous wave (LFM-CW) signal is presented, which uses a delay-line and a mixer to sense the slope of the output of a sweep oscillator.
Abstract: A technique for measuring the linearity of a linearly frequency-modulated continuous wave (LFM-CW) signal is presented. It uses a delay-line and a mixer to sense the slope of the output of a sweep oscillator, so that the original form of frequency function deviated from idealized linear slope is retrieved by means of spectrum analysis. Consequently, the linearity of the LFM signal is determined. The formulation is performed based on the principle that an angle-modulated signal can be approximated by an amplitude-modulated signal if the modulation coefficient is sufficiently small. To examine the validity of the procedure and to study the effect of each parameter on the accuracy of measurement, a number of computer simulations has been made. The results of simulation show that the error of the measurement is less than 2%.
TL;DR: In this article, a theoretic analysis of the analog division method for Kerr loop measurement is presented, and it is shown that the output signal V a can be expressed as V a = tan 2 ( φ ± θ K ), and the signal difference ΔV a is given by [sin(2 φ ) sin(2θ K )/[ cos ( 2 φ + cos (2 θ k )] 2, which means that the interference caused by the instability of I 0 is almost negligible.
TL;DR: In this paper, a low-temperature-flred semiconducting SrTiO3 ceramics were used to prepare multilayer grain-boundary layer capacitors (MBLCs) based on the conventional manufacturing process for multi-layer capacitors.
Abstract: Newly developed low-temperature-flred semiconducting SrTiO3 ceramics were used to prepare multilayer grain-boundary layer capacitors (MBLCs) based on the conventional manufacturing process for multilayer capacitors (MLCs). The compatibilities of ceramic materials with organic binder and inner electrodes and the effects of preparation methods were investigated. The experiment results showed that the method proposed by this study is a practicable technique for preparation of MBLCs.