最新刊期
卷 ， 期 6 ， 1996
- 摘要：A new fast algorithm is presented by combining method of lines（MoL） with FFT and diakoptic technique. In order to calculate the impedance elements by FFT,the Helmholtz equation of infinite period with oblique incidence is transformed to a new one. Then the current on the metal strip is calculated by using diakoptic technique. Compared with conventional MoL ,the new algorithm presented in this paper is more powerful. Numerical results computed are in good agreement with those published. Finally,the measured and calculated results of double gratings are presented.关键词：fast algorithm;Method of lines;Fast Fourier transform;Diakoptic technique;periodic structures2|73|2更新时间：2025-12-08
- 摘要：This paper presents a miniaturized"stepped impedance" patch microstrip antenna,the investigated High Temperature Superconductor（HTS） microstrip antenna was fabricted from YBa2Cu3O7-δ（YBCO） thin film exiptaxially grown on LaAlO3 substrate,the radiation efficiency of HTS antenna is 9. 19 times of the Au antenna for comparsion.A automatic measurement system for HTS antenna was constructed ,thorough experiment study was made,a lot of significance experimental datas were obtained and engineering experience was gained, it is shown that this automatic measurement system satisfies the special requirements of HTS antenna measurement very well. A invention patent was got for HTS antenna measurement apparatus.关键词：High temperature superconductor;microstrip antenna;efficiency;surface wave;miniaturized2|128|1更新时间：2025-12-08
- 摘要：This paper presents the soliton behavior of KdV equation stimulated by external signals, and developes a new method to detect dim moving point targets under high noisy background This method is based on a nonlinear system described by KdV equation. Finally, computer simulations are provided with a discretized real-time recursive algorithm.关键词：Solitary wave;resonance;Nonlinear dynamic system2|56|2更新时间：2025-12-08
- 摘要：The structure, operating and the characteristics of emission and stability of beam current for field emission gun（FEG） are reported. Experimental measurements show that if the vacuum in the gun chamber is better than 6. 67×10-7 Pa and the field emission current is 0. 9μA,the stability of beam current is better than 5% in 10 minutes,and if the acceleration voltage is 40kV,the radius of the virtual source of FEG is smaller than l. 3 nm and the brightness of FEG is higher than 5×109 A/cm2. sr. The results show that it is a new FEG of high brightness with very small beam spot. It can be used in SEM ,STEM and other electron probe systenis.关键词：Field emission gun;Stability of beam current;Finite radius of the vitual source;Brightness of FEG2|108|0更新时间：2025-12-08
- 摘要：In this paper, a spaceborne synthetic aperture radar（SAR） imaging processing algorithm using chirp scaling（CS） algorithm is presented. Comparing with range/Doppler（RD） algorithm, this algorithm avoids interpolation,yet performs range cell migration correction accurately,so CS algorithm provides image quality results better than the precision RD algorithm. The algorithm requires only complex multiplies and fast Fourier transforms to implement the processing.This paper describes the chirp scaling algorithm in detail,and using SEASAT-A raw data makes computer digital imaging. The results show that imaging method presented in this paper is effectlve.关键词：Spaceborne SAR;Chirp Scaling Algorithm;Radar imaging.2|458|29更新时间：2025-12-08
- 摘要：Considering the effect of the longitudinal uniform magnetic field,the microwave radiation produced by the interaction of a relativistic electron beam with a plasma column is examinned by use of the linear theory. It’ s shown that the E-mode and the Hmode produced by the interaction in the plasma column are coupled and undistinguished because of the effect of the longitudinal uniform magnetic field. The uncoupled condition of the E-mode with the H-mode and the dispersion equation of the E-mode are derived. And the calculations and discussions of the dispersion equation are presented.关键词：linear theory;Relativistic electron beam;plasma;Interaction;Microwave radiation4|60|0更新时间：2025-12-08
- 摘要：By using the methods of eigenmode expansion and mode-matching, the field distribution and the dispersion equations of hybrid modes in an inhomogeneous bianisotropic parallelplate waveguide are derived. With the help of numerical calculating technique,the effects of the geometrical and constitutive parameters of bianisotropic media on the reflection and transmission coefficients of lower-order propagating mode are investigated.关键词：Bianisotropics;Inhomogeneous parallel-plate waveguide;Eigenmode expansion;Mode-matching;Reflection and transmission coefficients2|92|0更新时间：2025-12-08
- 摘要：A camera calibration method for stereoscopic disparity metrology is described and discussed. It uses stereoscopic images of same objects with known position as input. Based on the projective geometry,and initial estimate of camera parameters is determined,and then the accurate estimate of camera parameters is computed by an iterated algorithm using the least square method.关键词：Stereoscopic disparity metrology;Camera calibration;Projective geometry;least square method4|88|0更新时间：2025-12-08
- 摘要：In this paper we presented a new idea of linked Faraday anomalous dispersion optical filter（FADOF）. The bandwidth of this linked FADOF is about 1GHz,and its noise rejection ratio is better than 10-6.关键词：Linked Faraday anomalous dispersion optical filter;Linkage;Noise rejection ratio2|50|1更新时间：2025-12-08
- 摘要：This paper discusses the methods of real-time correlation operation performed by the acousto-optic Bragg cell,and develops the mathematical models of the acousto-optic signal processing system that provides the correlation of high-speed digital pulse trains ,and a description of the system performance. The system utilizes a semiconductor diode laser,a Bragg cell with bandwidths of 100 MHz and aperture times of 7.4 μs,some lens and a photodiode-detector to perform the correlation operation in real time. With Barkor code sequences and its time inverse as inputs,the experimental results that correspond with the theory are obtained.关键词：Acousto-optics;Bragg cells;correlation2|93|15更新时间：2025-12-08
- 摘要：This paper have studied the dependence of the effective attenuation coefficient Г on both the parameters of system（height of plane H and field of view FOV） and parameters of sea water quality（volume attenuation coefficent c, single scattering albedo ωo） based on Monte Carlo simulation technology, which leads to an approximate formula of the minimum effective attenuation coefficient for the first time. The formula shows the quantity relationships between the effective attenuation coefficient and the parameters of sea water quality in the condition（H . FOV） is large enough, and provides powerful basis for the design of the lidar system.关键词：airborne;Oceanic lidar;monte carlo simulation;Effective attenuation coefficient2|241|14更新时间：2025-12-08
- 摘要：A new technique is introduced into the method of lines. Every dielectric layer of a multilayered multiconductor transmission line is equivalent to a two port network, the metal strips on the dielectric interfaces are equivalent to the current sources, all these have greatly facilitated the formulation procedure and have made the coding an easier task. Based on the quasi-TEM analysis of the multilayered multiconductor transmission line, a bilevel waveform relaxation method is used to calculate the transient response on every port, the results show that this algorithm is very fast and stable.关键词：Multiconductor transmission line;parameter extraction;Transient simulation;Method of lines;Waveform relaxation method.2|179|4更新时间：2025-12-08
- 摘要：The mathematical and physical properties of an algorithm for hierarchical fusion proposed in [1] are studied in this paper. First, the concepts for innovation and gain of fusing tracks are proposed. Second, their mathematical and physical properties are analyzed and proved.Final, we show that the hierarchical fusion estimate is a linear, unbiased, minimum variance estimate based on filter and prediction of each sensor. These properties reveal the essence of the hierarchical fusion eseianate in [1] and have of great value for solving problem on multisensor multitarget.关键词：data fusion;Hierarchical fusion;Fusion predict;estimation;Innovation;gain4|382|79更新时间：2025-12-08
- 摘要：A fast algorithm for MSMT data association, which includes initial association and fine association, is presented based on the fusion of local estimations. The data association algorithm[1] based on ternary searching is extended to MSMT case. On the basis of it, the relation between local position estimations at the main sensor and ones at others is given. The fine association is completed by using nearst neighbor JPDA（NNJPI）A). All local estirnations from the same targets are fused to obtain the global estiniations. A comparison of the algorithm here with the existing disiributed JPDA one is made, which shows that the algorithm here effeciently reduces computational cost with basic approximate performance.关键词：multisensor;multitarget tracking;data association;data fusion2|293|21更新时间：2025-12-08
- 摘要：A fuzzy sets-based method for radar weak target classification is proposed and studied. The membership functions of different radar targets are generated by using a two dimensional self-organizing feature mapping network. The kernel estimation of probability distribution and the consistent transformation between probability and possibility are employed by using the network. The problem of feature extraction for radar weak targets is simply discussed. The given testing results show that a high level of robustness and simultaneously a high accuracy of radar ship target classification have been reached by using the proposed fuzzy classification method. The method can be referred in other fuzzy pattern recognition areas.关键词：Fuzzy classification;radar target;neural networks;membership function2|99|6更新时间：2025-12-08
- 摘要：A method of GaAs FET large signal modelling using rneasured AM-AM and AMPM ourves is proposed, and the analysis means of intermodulation distortion and large signal gain in GaAs FET with single-tone AM-AM and AM-PM characterization is also presented. It can reduce complexity of analysis. The analysis is in agreement with experimental results.关键词：microwave;Field effect transistor;power amplifier;large signal modelling;Intermodulation calculation3|96|2更新时间：2025-12-08
- 摘要：The application of the nonlinearly constrained optimization method to low sidelobe synthesis of the space-scanned axial dipole arrays on cylindrical surfaces is discussed inthis paper.By adopting the information of the array element realized gain patterns, we propose an approximation method for finding the maximal sidelobe level of the scanned pattern with the prespecified beam pointing, and formulate the synthesis problem of the scanned arrays with the specified scan angle as nonlinearly constrained optimization problems. By using the new direct method, we can find a set of array coefficients that yield a scanned pattern, with the specified scan angle, meeting the specified sidelobe level and maximizing the directivity, if such a set of array coefficients exists.When the sidelobe specification can not be met, we can find a set of array coefficients that yield a scanned pattern meeting the best attainable sidelobe level and maximizing the directivity. Also,some numerical results for the low sidelobe control of the space-scanned axial dipole arrays on cylindrical surfaces are given.关键词：Axial dipole array on cylindrical surfaces;low sidelobe;directivity;Nonlinearly constrained optimization2|72|2更新时间：2025-12-08
- 摘要：Relationships between the scattering as well as absorption cross sections and polarizability of sphere-,needle-,disc-shaped dielectric-magnetic lossy particles of microwave absorbing materials are given in this paper. Calculations of the cross sections of carbonyl iron, ultrafine iron, ferrite and carbon particles have been carried out. The results show that the absorption cross sections of these particles are almost 1010 larger than their scattering cross sections. The absorption cross sections of disc- and needle-shaped carbonyl iron, ultrafine iron and carbon particles are larger than the absorption cross sections,of sphere-shaped particles. While ultrafine ferrite particles don’ t show this phenomenon, because its permeability becomes smaller than 1 in 9GHz frequency range.关键词：Ultrafine particles;Microwave absorbing material;Absorption cross sections;Scattering cross sections2|501|92更新时间：2025-12-08
- 摘要：A kind of matched filters in time-scale domain has been investigated in this paper based on continuous wavelet transforms, wavelet series and frame theory. It is shown that the wavelet based methods provide the same performance as traditional matched filters in ideal condition. Then we use it to detect transient signal with unknown parameters. Numerical examples and performance analysis show the method is effective and robust.关键词：Wavelet transforms;Wavelet series;Matched filters;signal detection2|277|13更新时间：2025-12-08
- 摘要：The paper presents a survey of recent advances in microwave nonlinear circuit theory, including two general-purpose analysis techniques for microwave nonlinear circuits, separately referred to as Modified Harmonic-Balance and Frequency-Domain Continuation Intermodulation Balance Methods, and their apphcations, as well as the numerical algorithms for nonlinear equations. The present popular research proJects in this field are also discussed.关键词：Microwave nonlinear circuits;Harmonic-balance;Intermodulation;Numerical algorithms;noise;sensitivity;stability2|972|23更新时间：2025-12-08
- 摘要：The concept of measured equation of invariance（MEI） is successfully applied to the computation of electrically large dielectric coated conductiong cylinder of arbitrary cross section. The MEI’s are used on the truncation boundary, which makes the truncation much closer to the scattering surface,thus reduces the computer memories requirements dramatically.关键词：Dielectric coated conducting cylinder;Measured equation of invariance;Electrically large dimension2|101|11更新时间：2025-12-08
- 摘要：In this paper, the similitude problem in aperture was examined. With the changes of aperture characteristic size, wavelength and the distance from observation plate to aperture,there are two different similarities in the diffraction field distribution for a specified aperture distribution, the strict similarity when electronical size is constant and the asymptotic similarity when it changes.关键词：Aperture diffaction;Convolution integration;Similarity.2|62|3更新时间：2025-12-08
- 摘要：A novel structure for integrated optical waveguide modulator is presented. It uses inverted coplanar waveguide as modulating circuit and decreases the mismatch between carrier and modulating wave,so the bandwidth of the modulator can be greatly increased. The analysis on the spectral approach is given.关键词：Travelling wave modulation;Invered coplanar waveguide;Spectral domain technique4|37|0更新时间：2025-12-08
- 摘要：The properties of the elliptically coaxial line with slotted outer conductor are studied by means of conformal transformations. The capacitance per unit length and charateristic impedance are given.关键词：Slotted coaxial line;Charcteristic impedance;conformal transformation2|76|0更新时间：2025-12-08
- 摘要：The properties of polarization adaptive counter-interference are analysed by using LMS algorithm in theis paper. After deduced the formulas of SINR ,Proceed with numerical calculation and imitation. As results.Except extremdy particular situation. The polarization adaptive counter-interference has obvious effect.关键词：adaptive;polarization;Counter-interference2|110|5更新时间：2025-12-08
- 摘要：In this paper,the telemetric transmitter on missile applying phase-locked technology is studied. High-speed wide-band PLL is designed with some novel components or chips,the high code rate, high frequency deviation and high-linearity in the transmitter are achieved. The transmitter are widely suited for various telemetric equipments on missile.关键词：Phase-lock;microwave;Telemetry;Frequency synthesizer2|102|7更新时间：2025-12-08
- 摘要：In this paper we investigate the relationship between the rate of decay of the radiated electromagnetic pulse energy and the exciting source. It has been shown clearly that the shorter the rise time of the exciting pulse. the slower is the decay of the radiated energy. It has also been demonstraed that for a pulse with a carrier the rate of the decay of the radiated energy can be decreased by increasing the carrier’s frequency.关键词：electromagnetic pulse;Rate of the decay of radiated energy;Rise time of pulse3|180|2更新时间：2025-12-08
- 摘要：A new method for computing propagation constants and amplitudes of creeping wave modes on an infinite conducting circular cylinder is presented. After acquired creeping wave currents on the surface of circular cylinder by its eigenfunction series, propagation constants and amplitudes of creeping wave current modes are obtainted by applying Prony’s method and complicated derivation is avoided. Numerical results obtained by applying Prony’s method are more accurate than those obtained by Keller’s formulas.关键词：Conducting circular cylinder;Creeping wave;Propagation constant;Prony’s method2|145|3更新时间：2025-12-08
- 摘要：In this paper,the mathematical model and the AAF of random binary phase-coded pulse radar signal are presented for the first time.Both the expression analysis and computer simulation show that the AAF is approximate to "thumbtack" form. and the signal of this kind can be used to measure the distance and velocity unambiguously, and the signal has good ability of counter-countermeasure.关键词：Random binary phase-code;pulse compression;average ambiguity function2|338|24更新时间：2025-12-08
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