最新刊期
卷 ， 期 6 ， 1992
- 摘要：Motion compensation is one of the key problems in ISAR imaging. Usually, the compensation process is based on an isolated point on target. However, in reality, this isolated point can not always be found. A new scheme which can compensate the motion effects for continuous target return is presented in the paper.关键词：ISAR;radar imaging;motion compensation0|199|8更新时间：2025-12-08
- 摘要：This paper presents a new numerical synthesis technique for low sidelobe curved arrays. The synthesis of curved arrays becomes a problem of nonlinear optimization, and can be solved by modified multiplier method to find a set of array coefficients that yield the best possible pattern directivity with specified sidelobes. To stress main points of this new technique, this paper deals chiefly with the mathematical model and computed results of curved arrays in free space. Results of linear arrays obtained by this new synthesis technique are compared with those of Taylor’s distribution. This synthesis technique is also suitable for conformal curved arrays.关键词：low sidelobe;Curved arrays;Numerical synthesis technique0|44|4更新时间：2025-12-08
- 摘要：The back scattering from a planar slot-array antenna is studied by the moment method and the technique of singularity elimination of the field integral. The scattering field from the conducting plane is computed by physical optics. Theoretical results of radar cross section （RCS） are compared with the measured ones, and good agreement is achieved. It is shown from this investigation that the scattering field contribution from the conducting plane is much greater than that from the slots.关键词：Slot-array antennas;Radar Cross Section;scattering0|85|3更新时间：2025-12-08
- 摘要：When a small scatterer which is relatively isolated and strong can be found in the imaging target, the motion compensation in ISAR imaging can be transfered into two steps: the range alignment for each return and the phase compensation of each return with the phases of the isolated scatterer. In this paper, we estimate the return Doppler frequencies from the return phases and propose a new way to resolve the Doppler ambiguities. Then the unambiguous Doppler frequencies are used to reconstruct the target trajectory so as to conduct range alignment for each return.关键词：ISAR imaging;motion compensation;Doppler frequency ambiguity resolution0|44|9更新时间：2025-12-08
- 摘要：In this paper we make a study of the backscattering of an electromagnetic missile with an energy decreasing as r-g by a perfectly conducting elliptical cylinder and a perfectly conducting sphere. The analysis indicates that the rates of the energy decay for the backscattered fields far from the elliptical cylinder and the sphere are proportional to r-（1+g） and r-2（2+g） respectively.关键词：Electromagnetic missile;backscattering;Backscattered fields0|78|3更新时间：2025-12-08
- 摘要：In this paper the third order geometric and first order chromatic aberrations for two types of combined electrostatic focusing-deflection systems, i. e. post-lens deflection system and in-lens deflection system, have numerically been calculated. The computational results show that in the case of matched curvilinear optical axes, it is possible to achieve smaller deflection aberrations in such combined systems. In the meantime, certain criteria for truly matching between focusing and deflection fields in combined systems have also been given.关键词：Combined electrostatic focusing-deflection system;Geometric aberration;Chromatic aberration;Curvilinear optical axis0|21|0更新时间：2025-12-08
- 摘要：A method to design Y-junction unilateral fin-line circulator is presented. The experimental results in Ka-band show that the transimission loss is less than 1.5dB, the isolation is larger than 20dB and VSWR is less than 1.3 over a bandwidth of 7%.关键词：millimeter wave;Integrated fin-line;Y-type junction circulator0|69|1更新时间：2025-12-08
- 摘要：In this paper, formula of equivalent dielectric constant in the central area of a ferrite toroid is presented by use of the energy equivalence method and in coordination with special conditions of latching ferrite phase shifter. Under approximate assumption, a theoretical formula used to calculate impedance matching is given. Calculated results are in good agreement with experimental ones.关键词：Back-Ridged waveguide;Ferrite phase shifter;Impedance match0|130|2更新时间：2025-12-08
- 摘要：The paper is concerned with high resolution microwave imaging of targets rotating in a small azimuth angle range. An unified formulation for image reconstruction is derived, which is applicable for all bi-static, mono-static, near-field and far -field imaging geometries. The superresolution imaging techniques are discussed and a new image reconstruction algorithm, which combines the spectral extrapolation with the use of coarse shape information derived from the imaging measurement data, is suggested. Lastly, the imaging results obtained in an anechoic chamber and related conclusions are given.关键词：Microwave imaging;radar targets;Imaging processing0|210|4更新时间：2025-12-08
- 摘要：The waveform distortion of sinusoidal pulse reflected from a collision moving plasma layer is investigated. On certain conditions, analytic expressions for the reflected waveform are derived. Numerical calculations show that the waveform distortion is large as ωa close to ωc. The reflected waveform distortion effected by dispersion, moving velocity and collision frequency is discussed.关键词：Waveform distortion;Moving plasma Layer;dispersion;Collision frequency0|25|0更新时间：2025-12-08
- 摘要：A new concept and procedure of the Global Numerical Boundary Condition （GNBC） is presented in this paper. A finite element analysis of 2-dimensional scattering of complex scatterers is given as example, demonstrating the application of GNBC in numerical solutions of differential equations for the open-region electromagnetic field problems. The present numerical approach not only has advantages of high calculation precision and efficiency, but also can deal with more complicated problems such as multiobject scattering.关键词：Electromagnetic field numerical analysis;electromagnetic scattering;Element analysis0|66|1更新时间：2025-12-08
- 摘要：The present state and developmental trend of research on electromagnetics are discussed according to Progress In Electromagnetics Research Symposium ’91, and some of new branches are also described in brief.关键词：electromagnetics;Developmental trend;’91 PIERS0|62|1更新时间：2025-12-08
- 摘要：The analytical expressions are derived for the integrals containing exponential and exponential integral which appear frequently in electromagnetic field problems.关键词：Exponential integral;Integration by parts;Fractional transformation;Closed-form expression of integration0|434|2更新时间：2025-12-08
- 摘要：The rectangular cone is mapped into a cylinder via conformal transformation in three dimensions. The maximum and the minimum values of characteristic impedance of a rectangular-coaxial-cone transmission line are obtained. The average of the two extreme values is in agreement with the characteristic impedance of the transmission line. The method enables one to design the characteristic impedance of BTEM cell accurately and easy.关键词：Rectaugular-coaxial-cone;conformal transformation;characteristic impedance0|121|8更新时间：2025-12-08
- 摘要：In this paper, the scattering characteristics of a plane wave incident on multilayered frequency-selective surfaces （FSSs） are analyzed by the method of moments combined with generalized scattering matrix theory. By introducing an idea of generalized waveguide, a unified treatment of multilayer FSSs with element of arbitrary shape is realised. As examples, the scattering characteristics of several structures are computed. Numerical results show good agreement with those published in literatures.关键词：Electromagnetic wave;scattering;Frequency-selective surface0|264|2更新时间：2025-12-08
- 摘要：The characteristics of the omni-directional periodic circular dielectric rod leaky-wave antenna are analyzed by the improved perturbation method. The electromagnetic fields are described in terms of a radial transmission-line network, which brings considerable physical insight into the overall behavior of the periodic antenna. The analysis yields expression for the leakagd constant in a closed form, and the design procedure of the antenna is tremendously simplified. Comparisons between the approximate and [rigorous results, as well as the experimenal data, are made. It is found that the accuracy obtained from the perturbation analysis is adequate for practical design purposes.关键词：Circular dielectric rod;Omni-directional leaky-wave antenna;Perturbation analysis0|59|0更新时间：2025-12-08
- 摘要：For the eigen-based direction finding technique, array sensor gain and phase uncertainties degrade severely its performance. This paper presents a new technique of calibrating the sensor gain and phase uncertainties of nonlinear array. At first we extract signal subspace ultilizing two radiating sources （time-disjoint） whose directions are not known accurately, then develop new iterative algorithms to solve nonlinear equations for estimation of sensor gain and phase factors. Simulation results demonstrate the pro-posd new technique’s performance.关键词：spatial spectrum;direction finding;calibration0|153|6更新时间：2025-12-08
- 摘要：<正> ASIC是国际上80年代VLSI发展过程中的一个产物,是一类为了某种专门用途而把多种通用IC集成在一起的芯片。ASIG的特点是生产批量小,周期短。ASIC的研制周期和费用包括芯片设计,制定工艺流程和测试开发所需的时间和费用。目前工艺水平发展很快,已能实现1μm以下的工艺。0|11|0更新时间：2025-12-08
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