最新刊期
卷 ， 期 9 ， 1993
- 摘要：In this paper,a 2-D temproal-spatial adaptive technique is proposed to suppress ground clutter for early warning radars based on a side phased array antenna.First,a multi-channel Dopplet filtering operation is carried out over the output data of each column subarray ,then Capon’s adaptive beamforming technique is applied respectively to process the output corresponding to the same Doppler filter.Theoretical analysis and computer simulation results show that the performance suffers little form the proposed approach degration in the presence of large random amplitude and phase errors existing in the array elements.In addition,it is not sensitive to the element failure.关键词：Airborne early warning radars;2-D temporal-spatial adaptive signal processing;clutter suppression;Adaptive array antennas2|1056|68更新时间：2025-12-08
- 摘要：In this paper,we study the theory of target imaging using FMCW millimeter wave technology,then present a novel method of reconstructing target with two-dimensional image under strong clutter background.This method has the advantage of not only better performance of suppressing clutter and noise but high resolution of super resolution spectrum estimation algorithm.The reconstructed image demonstrates features of spatial distribution of strong target scattering centers and can be applied to land vehicle target discrimination by millimeter wave anti-tank precision guidance.关键词：Target Imaging;Target discrimination;Precision guidance2|86|3更新时间：2025-12-08
- 摘要：This paper concentrates on the problem of finding a way to obtain angular resolutions better than the beam width of real aperture radars by means of azimuth signal processing.The model of the scaning process of real aperture radars is established,and the antenna pseudo-compression method is proposed based on generalized inverse filtering.The criterion of determining the optimum solution of the method is also presented.And the angular resolution is improved by a factor of about 5 by using this method in experiments.关键词：Real apertute;Generalized inverse filtering;Antenna beam effects;Antenna pseudo compression2|284|9更新时间：2025-12-08
- 摘要：A fullwave analysis method of ultra-short pulse photoconductive switches is described in this paper.Three-dimension Maxwell curl equations,including the conductive current components,are solved using a Finite-Difference Time-Domain scheme.The influence of the static electric field on boundary condition is taken into account in the analysis.And a more reasonable photoconductive mathematical model is employed here.The constituent of switch output,influence of laser pulse energy and width upon the switch performance and the responses of three-dimension field pattern in switch at different time are presented.关键词：photoconductive switch;Fullwave analysis;Time-Domain Finite-Difference method;absorbing boundary condition;Quasi-TEM modes;Plane waveguide modes2|66|3更新时间：2025-12-08
- 摘要：Based on 1-D wave equation,a reconstruction algorithm of layered acoustic impedance profile has been established in this paper.The algorithm can quantitatively reverse the acoustic impedance value and layered place of layered media to reconstruct the acoustic impedance profile of the layered media.The validity and practicability of the method has been proved by experiment results of computer simulation and real layered medium model.关键词：Layered medium;Acoustic impedance profile reconstruction;1-D wave equation2|79|1更新时间：2025-12-08
- 摘要：Based on theoretical research and calculation,the form of the correction model of groundwave propagation of Loran-c Chain in working zone on sea is determined and the formula of calculating the original values of parametera of the model and the method of iterated calculation of parameters are given.By fitting with the experiment data on sea measured during 1988-1991,the parameters of the correction model in working zone on sea of South China Sea Loran-c Chain are determined.The RMS of the deviation of calculated TD correction values according to the model from the measured ones is about 0.20.3μs.关键词：Loran-c;LF Groundwave;Correction Model2|73|1更新时间：2025-12-08
- 摘要：Using a new method,this paper shows that the 2-D characteristic polynomial A（z1,z2） =0 obeyed by 2-D sinusoidal frequencies may take four different forms.A data-direct approach is proposed for resolving several closely spaced 2-D sinusoids in white noise.This appproach adopts only the observed data rather than autocorrelations,and is shown to be of high resolution.关键词：Two-dimensional harmonic retrieval;ARMA modeling;Multichannel parameter estimation2|71|1更新时间：2025-12-08
- 摘要：In this paper a numerically derived absorbing boundary condition has been introduced to apply to the on-surface radiation condition （OSRC） method for the solution of open region scattering problems.Numerical results for perfectly conduction and homogeneous penetrable circular cylinder are presented and compared with the solutions by using second-order differential operator B2 type absorbing boundary condition.It is shown that the accuracy of OSRC method can be significantly Improved by using this kind of numerical absorbing boundary condition.关键词：electromagnetic scattering;On-surf ace radiation condition （OSRC） method;Absorbing boundary condition （ABC）2|16|0更新时间：2025-12-08
- 摘要：In this paper a realizing method of spaceborne synthetic aperture radar digital imaging is presented.Using SEASAT-SAR radar raw data,computer digital imaging is made.The imaging area is in range 2048 bins and in azimuth two aperture and about 38km×34km.We obtain high resolution radar imagery whose resolution is about 25m×25m.The results show that the imaging method presented in this paper is effective.关键词：spaceborne synthetic aperture radar;radar signal processing;radar imaging;motion compensation2|109|1更新时间：2025-12-08
- 摘要：A generalization of Born approximation in one-dimensional inverse scattering is derived by using an equivalent network technique,which is used to reconstruct the potential function of Schrodinger equation.Furthermore,a concept of effective reconstructing depth （ds） is introduced,and a constraint relation between potential function V（x） and ds is obtained.This relation is the applicable condition of Born approximation and its generalization.关键词：inverse scattering;Born approximation;Generalization of Born approximation2|111|2更新时间：2025-12-08
- 摘要：In this paper a differential equation describing the ABCD matrices of transmission is derived from the Telegrapher’s equation in the frequency-domain,thus the problem of time-domain re-spones analysis is transformed from a differential equation with boundary conditions to one with an initial condition which much easier to solve.Then the waveform relaxation method is used to numerically solve the ABCD matrices of nonuniform lines.A theorem about the convergence of the waveform relaxation method is proven.After obtaining the ABCD matrices,the time-domain respones of arbitrarily loaded transmission lines is easily analyzed with the FFT and convolution techniques.The given exem-ple demonstrates that this approach is reliable and efficient.关键词：Transmission lines;Time-Domain response;ABCD matrices;Waveform relaxation2|106|1更新时间：2025-12-08
- 摘要：The transient scattering of an electrically polarized,2-D pulsed wave by 2-D inhomoge-neous,lossy dielectric cylinder is investigated.In space discretization,a piecewise bilinear interpolation is used.THe integrals over patches are carried out analytically in closed form.The discretized equation in complex-frequency domain is sloved by using the CG-FFT method and the initial estimates are generated by using a new extrapolation scheme.Numerical results verify the efficiency of the new approach in this paper.关键词：Transient scattering;COM;Extrapolation;bilinear interpolation2|15|1更新时间：2025-12-08
- 摘要：This paper discusses the worst-case tolerance optimization of linear arrays,using excitation coefficients as design parameters.The problem considered is defined mathematically as a worst-case problem,a fixed tolerance problem（FTP）and a variable tolerance problem（VTP） and the new algorithms for solving this problem is presented.For solution of the FTP,we use the regular polyhedron method.The VTP is solved by a double iterative algorithm in which the inner iteration is performed by the FTP algorithm and the outer iteration is implemented by the comparison method.The VTP,which uses the largest discrepancy between the desired and the actual patterns in the tolerance region as the standard,harmonizes the relation between the array sklelobe level and the tolerance of excitation coefficients,so that the sidelobe level satisfies the desired requirements and the tolerance region is as large as possible.Finally,the numerical results of the 6-element and 16-element linear array tolerance optimization designs are given.关键词：Linear array;The worst-case problem;The fixed tolerance problem;The variable tolerance problem;Sidelobe level;Nonlinear optimization2|45|2更新时间：2025-12-08
- 摘要：A probe diameter （d） is the function of aperture angle （a） and magnification （M）,taking into account of a Gaussian probe,spherical,chromatic and diffraction aberrations of all lenses in a sysfem.With analytics,an equation for optimum α1 is derived to obtain the minimum probe diameter,when one of the two variables has been regarded as a constant We have also proved that d as a function of M and a has no extreme value if there is no any additional condition.关键词：Aperture angle;Cathode angular current intensity2|35|1更新时间：2025-12-08
- 摘要：In this paper the criteria of choosing phase reference of motion compensation in inverse synthetic aperture radar （ISAR） are proposed with the phase information of radar echoes.The radar images of a real flying Boeing airplane are obtained successfully through actual observation data.Then the superiority of the new criteria is confirmed.关键词：ISAR;Phase reference;Amplitude variance;Phase variance2|41|2更新时间：2025-12-08
- 摘要：By means of frequency selective surface （FSS） instead of metallic surface,a stealthy reflector antenna with small radar cross section （RCS） is constructed.The experimental results show this antenna can obtain about 15 dB of RCS reduction and similar radiation properties in comparison with ordinary metallic reflector antenna.关键词：Frequency selective surface;Stealthy reflector Antenna;RCS2|110|2更新时间：2025-12-08
- 摘要：Due to the quantization of electromagnetic fields there is an upper frequency limit in the spectrum of any finite energy transmitted by an electromagnetic system.It is shown that the existing electromagnetic missile theory is based on the classic theory.The electromagnetic missile is not feasible physically.Subsequent attempts to realize or utilize the electromagnetic missile phenomena theoretically and experimentally are in conflict with existing quantum theory.关键词：Quantum effect;Wave propagation;Space decay3|64|2更新时间：2025-12-08
- 摘要：In this paper,propagation constant formula for twin ferrite toroidal phase shifter using Back-Ridged waveguide is given.With typical parameters,the differential phase shift and the insertion loss are calculated.The results show that the figure of merit and the differential phase shift of the phase shifter are larger than these of rectangular waveguide phase shifter under the same condition.To prove the equation given in the paper,differential phase shift is measured by experiment.The results are basically agreement with those calculated by given equation关键词：Back-Ridged waveguide;Ferrite phase shifter2|61|3更新时间：2025-12-08
- 摘要：Electromagnetic missiles have been ever investigated in terms of approximation solution of Maxwell equation.It is doubtful whether this problem can be analyzed strictly.According to current distribution of radiation source,only using vector potential A to denote electromagnetic field,this paper presents the strict solution for electromagnetic missiles.It lays the mathematical foundation for analyzing propagation properties of arbitrary excitation waveforms and understanding slow attenuation mechanism of electromagnetic missiles.关键词：Electromagnetic missile;Radiation source;Vector potential2|83|3更新时间：2025-12-08
- 摘要：<正> 由中国计算机学会主办的第三届国际青年计算机学术会议（ICYCS’93）于1993年7月15日至17日在北京举行。国家智能机研究发展中心主任李国杰研究员担任大会主席,哈尔滨工业大学高文教授和清华大学吴建平副教授担任大会程序委员会主席。大会共收到来自25个国家和地区的论文400篇,其中国外论文183篇。由国内外各领域的专家学者对论文进行了三级严格评议。从400篇稿件中挑选出190篇论文大会正式录用,其中120篇论文是国外的。入选论文及其入选的比例充分体现了作为一次重要的国际学术会议的较高的学术水平。会议论文集《ICYCS’93 Towards the future》已由清华大学出版社正式出版,国内外发行。2|9|0更新时间：2025-12-08
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