最新刊期
卷 ， 期 6 ， 1994
- 摘要：A new approach for clutter suppression in airborne phased radar is presented in the paper. It belongs to the class of data transformation method. The transform matrix is dependent on the combined channel subspace spanned by main channel and auxiliary channels.By designing the main channel,the transform dimensionality is reduced to M+K-1（M is the number of sensors and K is the number of pulses）.The transformed optimal weight is obtained in this M +K-1 dimensional signal subspace. This approach can approximate the 2D optimal array well even under array errors and clutter fluctuations,and its volume of computation is much less compared to 2D optimal receiver.关键词：airborne radar;Spatial-temporal adaptive processing;clutter suppression;adaptive array2|171|32更新时间：2025-12-08
- 摘要：In this paper,a comprehensive method of estimation of Doppler Centroid and Doppler Frequency rate for spaceborne SAR are demonstratde. This method can provide Doppler parameters automatically in the case of lacking data of satellite ephemeris and satellite attitude. This method is proposed based on the properties of Doppler parameters and estimation error of Doppler parameters.Finally,the raw data of Ocean satellite SEASAT-A are used to test effectiveness and feasibility of this method. The results of imaging with raw data are presented to verify the validity of the approach.关键词：Synthetic aperture radar（SAR）;Doppler parameter estimation;range migration2|446|27更新时间：2025-12-08
- 摘要：In the present paper,computation of electrostatic field distribution for conical immersion lenses is studied by using the boundary element method（BEM）,and the electron trajectories incident from the object and image spaces have been traced using a set of curvilinear paraxial trajectory equations and practical trajectory equations, then the electron optical paramenters, such as cardinal points of lens, have been determined. The computational results coincide with the analytical asymptotical method given by S. Ya. Yavor et al.关键词：Conical lens;electron optics;boundary element method2|49|3更新时间：2025-12-08
- 摘要：A dipole antenna array in conform with a finite hollow cylinder is presented in this paper. The method of moments（MOM） and the inversion of block matrix are also adopted. As an example,the element pattern of a dipole in array and its input impedance are calculated.关键词：Conformial arrays;method of moments;Block matrix;Element pattern2|195|1更新时间：2025-12-08
- 摘要：In this paper an efficient analysis for the response of dual lateral logging（DLL） tool in complex environment has been presented. The computer code for DLL analysis based on the theory in this paper has been developed and the results are in excellent agreement with the data published previously. It can be used to analyse quantitatively the combined effect of borehole, mudcake, invation and shoulder beds on DLL response,to provide numerical simulation for design of new sonde and to develop computer-aid logging interpretation software.关键词：Electrical well logging;Dual lateral logging;Numerical mode matching2|253|64更新时间：2025-12-08
- 摘要：General dielectric boundary conditions for electrostatic problem in inversion transformation are described. It is shown that solution to electrostatic problem of two dielectric spheres with cloesd form cannot be reached by using inversion. Multiply-multipole method is applied to the problem and accurate results are obtained. The numerical results confirm the addition theorems for spherical harmonics.关键词：electrostatic field;Spherical harmonic expansion;Inversion transformation2|54|1更新时间：2025-12-08
- 摘要：In this paper,the Method of Lines（MOL） is successfully extended to solve the EM wave scattering problems of two dimensional metallic periodic surfaces. Cornpared with available of matrix elements is needed to be handled in numerical calculations. Meanwhile,the method presented in the paper possesses the advantage of less computation. The results of groove,comb and sinusoidal surfaces are presented.关键词：EM scattering;Periodic surface;Metallic grating;Method of lines2|125|2更新时间：2025-12-08
- 摘要：Angle-Doppler spectrum of clutter returns received by airborne surveillance radars based on a side phased array antennas appears as some kind of ridge. The simplified processor based on the "ridge"clutter spectrum suffers great performance degradation, in the presence of amplitude and phase errors between array elements. The reason for the performance degradation is analysed and a new modified 2-dimensional processor is proposed in this paper.关键词：Airborne radars;2-D spatial-temporal adaptive signal processing;clutter suppression;Adaptive array antennas2|176|16更新时间：2025-12-08
- 摘要：In calculating the scatter parameter of the complex system,there may be matrix of unfilled rank which results in interruption of the CAD process. This paper analyzes the source of this singularity ,pointing out that such case is corresponding to the resonance of some sub-network. The algorithm to deal with such case is given. This method is applied to the CAD calculation.关键词：CAD;Resenant system;complex network;Scatter parameter2|52|0更新时间：2025-12-08
- 摘要：In this paper,the dyadic Green’s functions of an electric current source in spherioal multilayered chiral media are derived first using the method of scattering superposition. The radiated fields and normalized radiation resistance are studied for a point dipole antenna located at the center of a chiral spherical shell. The effect of chirality admittance on the transmittance properties of chiral spherical shell is also investigated using the plane-slab approximation. The results show that the polarizated state of radiated fields can be regulated by changing the normalized thickness of chiral spherical shell.关键词：Chiral media;Chirality admittance;Dyadic Green’s function;Radiation resistance;Impedance match2|49|2更新时间：2025-12-08
- 摘要：By employing the spheroidal vector wave function expansions for the incident and scattered fields and the impedance boundary conditions on the coated surface,an analytic solution of the plane electromagnetic wave scattered by a coated prolate spheroid for axial incidence is derived,and numerical calculations are obtained.关键词：Vector wave functions;Impedance boundary conditions;Scattering cross sections.2|63|2更新时间：2025-12-08
- 摘要：In this paper, a computer automatic division technique for 3-D finite element method is proposed to facilitate the development of the general computer program. By combining the automatic division with the sparse matrix techinques,the solution procedure of 3-D finite element is significantly simplizied and the solution efficieney is raised.The scattering characteristics for several descontinuity structures are calculated and the seliability and the practicality of the pressent program are verified by the calculated results amd exrerimental Eata given in the literature.关键词：D finite-element method;Computer automatic division techmique;Discont inuities in waveguide2|112|5更新时间：2025-12-08
- 摘要：The interaction of the pulse electromagnetic field with human body using the Finite-Difference Time- Domain（FD-TD） method and the inhomogeneous block human body model is discussed in this paper. To verify the validity of the method,the first step is calculation of the currents induced in the infinite long dielectric circular cylinder expoused to pulse EM wave. Then the currents induced in 2D and 3D inhomogeneous block human body models under the expouse of unclear EM pulse are calculated. The current versus time and the current distributionof the whole body model are calculated too. The influence of the medium dispersion isn’ t considered, it’ s a further research problem.关键词：Nuclear electromagnetic pulse;finite-difference time-domain method;Inhomogeneous block human body model2|299|32更新时间：2025-12-08
- 摘要：A new method and annovel circuit of the optically tuned DRO are pressented. The optical input changes the conductance of a GaAs photosensitive sample which causes the inverse voltage of the varactor diodes to be regulated , resulting in a shift of the central frequency of the DRO. The optical tuning range 32 MHz in 3. 4 Ghz has been obtained with a little change in output power of the DRO.关键词：Optical-microwave interaction;Optical tuning of microwave devioes;Optically tuned DRO.2|57|1更新时间：2025-12-08
- 摘要：In this paper,the dispersions of cylindrical microstrip lines and coupling line are simulated by using the full-mode method,so called the two dimensional FD-TD method in cylindrical coordinate system. The basic theory and treatment of this method are discussed in detail,then the dispersive chatacteristrcs of cylindrical microstrip lines with different metal strip width and the coupling lines with different coupling gap or coupling strip are obtained. These results are valuable for the design of transition region in MIC and MMIC.关键词：microstrip;Cylindrical;FD-TD method;dispersion2|61|0更新时间：2025-12-08
- 摘要：This paper presents a bispectrum method to detect the dynamic nonlinearity of high speed analog-to-digital converter（ADC） and points out that the bispectrum method can greatly suppress the quantization noise and improye the sensitivity in dynamic nonlinearity detection. The simulation experiment shows that the bispectrum has higher detection resolution than power spectrum method.关键词：Analog-to-digital converter（ADC）;harmonic distortion;Dynamic nonlinearity;bispectrum2|93|0更新时间：2025-12-08
- 摘要：The target height measurement theory is buih and the factors that influence the accuracy of the height measurement are investigated. The errors and suitable ranges of the various algorithms for height measurement are calculated by simulation. The paper also suggests a method to modify the influence of the globe curvature and a general approach dealing with the height measurement problem.关键词：bistatic radar;Height measurement;Superiority region;Globe curvature2|176|9更新时间：2025-12-08
- 摘要：In an electrostatic field the relationship of the variation of the field magnitude along a flux line（dE/dn）+2H（n）E=0 has been derived by the geometrical method. Its exact and approximate solutions of field magnitudes can be obtained in a specific condition. It is noted that when it is used on a boundary of the field ,the solution can not be used to obtain any exact formulation for the surface charge density on a coductor.关键词：electrostatic field;Equipotential surface;Surface charge density2|55|1更新时间：2025-12-08
- 摘要：This paper strictly analyzes the problem of circular edge of incomplete dielectric sphere excited by an external uniform field E0 in the toroidal coordinate and gives some important integral formulae.In special cases,the result is the same as the published literatures.关键词：Circular edges;Electrostatic problems;Integral formula;Electromagnetic cornpatibility2|31|0更新时间：2025-12-08
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