最新刊期
卷 ， 期 3 ， 1996
- 摘要：The reflection of electromagnetic waves from inhomogeneous medium with a special profile is investigated. The function form of the special profile,an invers square profile,is first derived using a matrix analysis theory. Furthermore,the reflection coefficient in closed form,which is given by simple elementary functions. Some examples are given to test the validity of the presented formula.关键词：Matrix analysis theory;Matrix functions;Electromagnetic waves;reflection2|70|1更新时间：2025-12-08
- 摘要：Fowler-Nordheim formula is a theoretical formula for calculating field emission currents. It was derived under some idealized conditions. Experimental measurements show that field emission current from actual field emitters are always much larger than that calculated from Fowler-Nordheim formula. It implies that this idealized formula for actual field emitters must be modified. The reasons for modification and an appropriate quantitative method to modify this formula are given.关键词：Fowler-Nordheim formula;field emission;Field emitter2|548|7更新时间：2025-12-08
- 摘要：A theory of electrostatic and magnetic imaging with any specified image rotation has been studied,and it develops our previous theory of electrostatic and magnetic imaging. The conditions of the axial electric potential and magnetic induction for realizing electrostatic and magnetic imaging with any required image rotation have been given,and the results show that the given theory can realize not only an erect positive image but also a specified rotated image（or an inverted image）. As an example,an analytical distribution of axial electric potential and magnetic induction has been given for obtaining the electrostatic and magnetic imaging with any specified image rotated angle and magnification M=1 or M≠1.关键词：electron optics;Electron lenses;Electron focusing;Cathode lenses;imaging systems2|50|0更新时间：2025-12-08
- 摘要：The Poincare surface-of-section maps and Lyapunov exponents have been used to demonstrate the chaotic charateristics of electron motion in a plasma wave wiggler. The results show when the field strength of wiggler increases the electron motion changes from the regular state to chaotic mode. This is an important problem which has to be solved when the output power of free electron laser increases.关键词：Free electron laser;Plasma wave wiggler;chaos2|34|1更新时间：2025-12-08
- 摘要：A new type of MM-wave TWT slow wave system──double staggered ladder circuit is analysed in this paper,by means of the 3-D finite element method and cavity field average value method,the dispersive characteristics and the 3-D field distribution are obtained. An experimental research is done,and the result is fit well to the theoretical one.关键词：Ladder coupling chain;3-D finite element method;Dispersive charateristics;Cavity field average value method2|78|20更新时间：2025-12-08
- 摘要：The analysis of the transmission property of submillimeter wave in nonliear antiferromagnetic slabs is presented. The influence of the different dielectric constants of the three layers on the bi-and multi-stabilities are discussed in detail.关键词：Nonlinear antiferromagnet;Bistability2|26|0更新时间：2025-12-08
- 摘要：A numerical method for determining diffraction coefficients for edge of half-infinite metallic plate is described. We use the Finite-difference Time-domain （FDTD） method to compute the scattered field of an object possessing several scattering centers. The numerical diffraction coefficient of the scattering center under investigation is then isolated by solving simultaneous equations established based on GTD consideration. This method yields numerical diffraction coefficients for the edge of conducting strip and the one partially or fully coated by absorbing material for which the analytical diffraction coefficients are not known to our knowledge. Some examples show the feasibility.关键词：Diffraction coefficient;numerical method;FDTD method;Coated strip4|84|2更新时间：2025-12-08
- 摘要：In this paper,the step frequency response equation of optical-region radar target is firstly established by using theories of multiple scattering centers and local resonance. In the equation,different approximate model is used to describe the local Rayleigh or resonant response of each scattering center. Then a novel method of target structure imaging based on band-limited response data for target spacial features extraction is presented. The obtained quasi-two-dimensional image provides target features of not only range response under wide-band waveform stimulation,such as one-dimensional range profile,but geometrical structure category of each local scattering center also. The features can be used for radar target identification.关键词：Radar target identification;radar imaging;Superresolution spectrum estimation;Frequency response2|149|11更新时间：2025-12-08
- 摘要：The Chirp Scaling（CS） algorithm is an dfficient and high resolution imaging algorithm used in airborne SAR with wide antenna beamwidth or with very high squint angle. Based on the CS algorithm,this paper proposes a new extended chirp scaling（ECS） algorithm,which modifies the phase functions and processing structure comparing CS algorithm in order to accommodate the motion compensation phase needed in the airborne SAR to obtain the high resolution image even for the aircraft antenna with very high squint. The E-SAR raw data obtained by Gerospace Establishment（DLR） is processed to confirm the validity of the ECS algorthm.关键词：Chirp Scaling Algorithm;Airborne squint SAR2|217|16更新时间：2025-12-08
- 摘要：In this paper,the adaptive space-time processing of array antenna placed on the aircraft arbitrarily is studied. An approach has been proposed,which is processed by the way of adaptive space-time processing combined with using multiple pulse repetition frequencys（PRF）.We analyze the system performance of time-space cascaded adaptive processor and study the optimum design of PRF. Theoretical analysis and computer simulation results show this approach is practicable.关键词：airborne phased array radar;2-D space-time adaptive signal processing;clutter suppression;Pluse repetition freqency2|147|10更新时间：2025-12-08
- 摘要：A method of calibrating the sensors’ position,gain and phase uncertainties of linear equi-sqaced（LES） array is presented. This method can be applied to non-linear array too. A technique to estimate the level of error of array is also developed. Computer simulation and practical example results illustrate that this method is effective.关键词：MUSIC method;Calibration;Direction of arrival2|1229|181更新时间：2025-12-08
- 摘要：A strip-type circular polarizer consisting of multi-planar periodic surfaces is investigated by combination of scattering parameters of each periodic surface. The scattering parameter of every surface is analyzed by the Galerkin method in spectral domain and the entire domain basis functions are selected. The calculated VSWR and axis ratio of the circular polarizer agree quite well with the experimental results. Thus,the effectiveness of the analysis is verified.关键词：Circular polarizer;Periodic strip;Entire domain basis functions;Floquet mode2|240|9更新时间：2025-12-08
- 摘要：This paper studies the performances of the OSCAGO-CFAR detector[1,2] under clutter edge situation. We derive the analytic expressions of false alarm probabilities under clutter edge situation,analyse its performances against clutter edge,and compare it with the GO,OS and CA-CFAR detectors. The results show that the anti-clutter-edge performance of OSCAGO is obviously better than that of the three CFAR detectors. At the same time,it preserves the better detection performances in homogeneous backgroud and multiple target situations.关键词：radar;signal detection;CFAR;Clutter edge2|118|9更新时间：2025-12-08
- 摘要：Using the Sierpinski gasket as an example,the paraxial Fraunhoffer-zone transmitted field of a self-similar growing fractal screen is analyzed. It has been shown that this transmitted field also exhibits self-similarity.关键词：Sierpinski gasket;Growing fractal;Transmitted field;Fourier transform2|22|0更新时间：2025-12-08
- 摘要：A quasi-static approach is demonstrated for the equivalent transmission line characterization of multiconductor interconnects for multichip-module（MCM） with perforated reference planes by using the "method of lines". The proposed method can be used to extract effective transmission line parameters for multiconductor interconnects. The results of some examples are also given.关键词：多芯片组件;多导体互连线;电磁参量提取2|52|4更新时间：2025-12-08
- 摘要：Based on the uniform geometrical theory of diffraction,the equivalent current has been used to calculate the backscattering field for the finite cone,then the scattering matrix including information of polarization has been gotten,assuming that the incident wave is complete planepolarized wave. The optimized state of scattering polarization is worked out through energy-scattering matrix,and all the numerical results are given.关键词：polarization;Matrix of polarized scatter;Finite Cone4|34|1更新时间：2025-12-08
- 摘要：Propagation chracteristics of the chirowaveguides have been calculated using a generalization of the electric and magnetic fields. The edge-element method has been used,therefore no any spurious modes exist. The rectangular chirowaveguide is considered,the effect of chirality mode admittance and size of chirowaveguides on cutoff frequence is studied. The effectiveness and accuracy of edge element-method are proved.关键词：边元法;矩形手征波导;手征导纳;混合模2|50|0更新时间：2025-12-08
- 摘要：A new calibration method for dielectric measurement by sing six-port reflectrometer is described. This method combines two separate calibration procedures of six-port and openended coaxial line into one, and is especially suitable for on-line dielectric measurement.关键词：Open-ended coaxial line;Sixport;Dielectric constant.2|92|3更新时间：2025-12-08
- 摘要：A recurrence algorithm for computing Bessel functions of arbitrary ordes v and complex argument z is presented in this paper. Some typical numerical results are given and five means of examining the computation accuracy of the results obtained are analyzed and discussed.关键词：Bessel functions;Arbitrary order;Complex argument2|472|6更新时间：2025-12-08
- 摘要：The propagating characteristics of hybrid modes in Faraday chirowaveguides are studied. In such bianisotropic complex guided wave structure,the transverse field components are expressed in terms of their longitudinal field components. Numerical results are presented for the dispersion and attenuation behaviours of different hybrid modes using the Mller’s method of calculating roots,and the effects of different constitutive parameters on the propagating characteristics are considered.关键词：Faraday chiral medium;Chiroferrite;Chirowaveguide;hybrid mode2|48|3更新时间：2025-12-08
- 摘要：A modified extended coherent processing（MECP） method is proposed in this paper to reconstruct near-field microwave images of conducting objects which are mounted on a rotating platform. In the method, the results of range-Doppler （R-D） imaging in all subintervals of the total rotating angle are corrected for the near-field case and then coherently added together.The simulation results show that the MECP method not only needs less calculation but also is more efficient than the SBP algorithm.关键词：radar imaging;inverse scattering;near-field2|90|3更新时间：2025-12-08
- 摘要：Newton-Kantorovich method combined with moment method is applied to solve the nonlinear coulped integral equations arising from imaging of conducting object illuminated by plane waves with multiple frequencies and multiple incident directions in the paper, pseudoinverse technique based on Gram-Schedmit procedure is adopted for the solution of ill-conditioned linear equations. Least square error method（LSE） is adopted to calculate the initial values. Two techniques are also introduced to reduce the CPU time. Numerical results have shown the validity of the method and high tolerance of noise.关键词：Newton-Kantorovich method;Imaging of conducting object;moment method;Pseudoinverse technique2|69|1更新时间：2025-12-08
- 摘要：The problems of high stability and low phase noise of 3mm-wave source are solved by use of PLL. It is measured that when Fourier frequency is 1kHz and offset carrier is 92. 7GHz, the phase noise of 3mm-wave PLL source is-75dBc/Hz. Spurious is lower than-55dBc and output power is higher than 10mW.关键词：PLL;mm wave;phase noise;Source2|142|17更新时间：2025-12-08
- 摘要：In the paper, the effect of the phase difference of coherent signal emitters on the resolution performance of DOA estimation is investigated, and some interested results are obtained. And the way to improve the performance is considered.关键词：DOA estimation of non-centrosymmetric array;array manifold;Cramer-Rao bound2|129|2更新时间：2025-12-08
- 摘要：Based on the nonlinear of synchronized oscillators,the expression of locking range for fundamental wave injection locked 2nd harmonic Gunn Oscillators is derived. The experimental researches of fundamental wave injection locked 2nd harmonic Gunn oscillators in 3mm band are completed. The theoretic analysis conforms to the experimenal results.关键词：millimeter-wave;Gunn devices;Harmonic oscillators;Nonlinear Circuits;injection-locked4|190|13更新时间：2025-12-08
- 摘要：The structure and dielectric properties of BaO-TiO2-Nd2O3,（BTN） ceramics are studied. Doping with appropriate amount of glass and additives in the system,a series of temperature compensating monolithic capacitor ceramic （MLC） is obtained at intermediate firing temperature. The experimental results prove that the Curie temperature （Tc） of BTN ceramics shows a gradual shift with the increasing of Nd2O3 when Ti/Ba=1.003. The micrographs taken by SEM show that the grain size depends on Nd￣（3+） content. The influence of Ti/Ba ratio on the temperature coefficient of permittivity （αε） of the ceramic has been investigated. The permittivity （αε） and（ε） of BTN system can be adjusted both by changing the Nd2O3 content and Ti/Ba ratio. Moreover,the influences of CaTiO3 on the electrical properties of BTN are also analyzed.关键词：Intermediate temperature sintering;Monolithic capacitor ceramic;temperature compensation2|31|0更新时间：2025-12-08
- 摘要：A theoretical study of the coherence function in random media is presented. The early result on the coherence restricts the observation points on the scan plane which is perpendicular to the propagation direction. In this paper, the restriction is abolished, and the new result can be applied to any cases.关键词：Random;Coherence function;EM theory1|32|0更新时间：2025-12-08
- 摘要：A novel numerical boundary condition is presented in the paper, which is compared with the method of measured equation of invariance（MEI） on computational time and memory requirement. It is demonstrated that the new boundary condition is of benefit both on the time and memory, therefore is an efficient method for computation of electrically large dimension objects.关键词：boundary condition;Measured equation of invariance;Electrically large dimension4|59|3更新时间：2025-12-08
- 摘要：This paper has studied the spreading of light beams in airbome oceanic lidar for detecting underwater targets using Monte Carlo simulation method. In various conditions of the ocean, spreading radii of light spots on the various depths under water are obtained, which are coincided with the related results published abroad. For the first time, we have calculated the spreading radii of the light spots just above the water surface that are reflected by the target and the distribution of radiance within them, We have also studied the influence of sea wave and foam on spreading of light beams. These results are very important for the design of the airborne oceanic lidar.关键词：Airborne oceanic lidar;underwater target detection;Monte Carlo simulation;Spreading of light beams;Optical scatter;Sea wave;Foam2|278|14更新时间：2025-12-08
- 摘要：A procedure for RCS computation based on Auto CAD modelling is given, and an algorithm for getting model information from DXF file of Auto CAD is described. A practical approach to RCS computation of complex targets with PC is then presented.关键词：electromagnetic scattering;radar cross section;Modelling3|140|8更新时间：2025-12-08
- 摘要：We use the finite-difference time-domain（FDTD） algorithm to simulate microwave pulse couplings into narrow slots which have depths much narrower than one FDTD cell.We present the dependence of the microwave pulse coupling on the carrier frequency of incident wave, polarization direction, cavity wall conductivity and narrow slot sizes. Simulation results show that there are resonant effect and enhancement effect occured in the processes of microwave pulse couplings into narrow slots.关键词：microwave pulse;linear coupling;Resonant effect;Enhancement effect2|120|23更新时间：2025-12-08
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- 摘要：An algorithm to obtain the covariance matrix is presented. Only based on the adaptive array ouutput power,the array covariance matrix can be obtained by a weight perturbation method.关键词：covariance matrix;Weight perturbation;Adaprive array output2|119|23更新时间：2025-12-08
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