最新刊期
卷 ， 期 3 ， 1998
- 摘要：In this paper an HTS circular polarized microstrip antenna was prepared.Its working frequency is 6.26GHz.The DC magnetic field dependence of the transmission coefficient of the antenna at B≤1T and T= 4.2K was presented.The circular polarization property of the antenna was also measured.It is concluded that the transmission coefficient and circular polarization ratio hardly change with DC magnetic field up to 1T at 4.2K.关键词：magnetic field;Crrcular polarized microstrip antenna;Transmission coeffcient;Circular polarization ratio;HTS（High temperature superconductor）2|85|0更新时间：2025-12-08
- 摘要：A full-wave integrated time domain analysis of the 1×16 element microstrip array antenna is carried out by finite difference-time domain（FDTD）method.The modified Berenger PML（MPML）absorbing con dition is used in the analysis.The MPML is more efficient in absorbing the evancescent energy and keeping the same performance for propagating modes.This good behavior of MPML is improtant in our analysis.Compared to isolated microstrip antenna,more slow decay evancescent waves are included near nicrostrip antenna array.It is shown that the MPML results are more accurate than the PML ones关键词：Microstrip array antenna;Finite difference-time domain;absorbing boundary condition3|204|1更新时间：2025-12-08
- 摘要：The pseudo-range error due to multipath effects in the GPS system is studied.First the time de lay of specular multipath aignals and its freqency bandwidth spread are analyzed.Then an extensive study is car ried out for the influence of multipath signals to the S-curves and the peudo-range errors when tracking the PN code signals with coherent and noncoherent delay lock loops.Moreover,several methods for reducing multipath er rors are proposed.关键词：GPS（Global positioning system）;multipath effect;Pseudo-range error2|1277|23更新时间：2025-12-08
- 摘要：This paper presents two fuzzy track correlation algorithms with double threshold applying to dis tributed multisensor data fusion.In the paper,composition of fuzzy element sets,selection of membership function,dynamic assignment of weight vectors,track mass design,multivalency processing methods,fuzzy double threshold track correlation criterion and fuzzy classical assignment problem are discussed.Moreover,the algorithms are com pared with two classical methods through simulation.The simulation results show that the performance of the fuzzy double threshold track correlation algorithms is much better than tha of the classical methods in dense multitarget environments,more cross,split and maneuvering track situations.Under the above situation their correct correlation rates are improved about 35 percent over the classical methods.关键词：data fusion;Track correlation;Radar network;pattern recognition;fuzzy set2|521|18更新时间：2025-12-08
- 摘要：Starting from the integral form’s Kirchhoff’s law,the superposition theorem in most general lin ear network including mutual induction was proved strictly.关键词：Linear network;Linear network including mutual induction;Superposition theorem2|43|3更新时间：2025-12-08
- 摘要：A new beamformer is ppesented in this paper,which utilizes the eigenstructure of the correlation matrix to enhance the performance of the linearly constrained minimum variance（LCMV）beamformer.The advan tages of the beamformer are that it can eliminate the sigmal cancellation when a desired signal is contained in the correlation matrix,and has good beam pateern with low sidelobe level and fast convergence properties,which are confirmd by computer simulation.关键词：Adqptive beamforming;array signal;Interference cancellation2|532|12更新时间：2025-12-08
- 摘要：In the paper,an improved tomographic tomographic algorithm is put forwarded according to the high resolu tion imaging capability on small terrain during the spotlight mode SAR procedure.By simplirying the pro cedure of Fourier reconstruction,reducing the A/D rate and PRF,implementing initial phase compensation,facil itating the hardware materialization,this new improved DFR algorithm greatly benefits the imaging proceessing ef ficiency.Necessary explanations,deductions,figures,tables and simulation results are given out.关键词：Spotight Mode SAR;Computer-aided Tomography2|138|1更新时间：2025-12-08
- 摘要：Based on the eigen-driven analysis method of circular array,a decoupling method is proposed in this papee.This method transforms the pattern synthesis of circular array with coupling to the pattern synthesis without coupling.It combines ideal pattern synthesis methods with eigen-driven analysis method that considers coupling affect between array elements.To certify the valid of this method,an array structrue is calculated and some results are presented and discussed.关键词：Decoupling analysis;Eigen-driven;circular array3|296|4更新时间：2025-12-08
- 摘要：A multi-sensor multi-filter compound is presented to track 3D targets which can limit the ac tive transmission using a radar providing sporadic range data to aid in the system where a passive IRST is the primary senaor for track maintenance.Furthermore,an Interactive Multiple Model approach is employed to im prove the system availabilities with overcoming the tracking difficulty resulting from nonlinear movement of tar gets in the 2D bearing coordinate system of IRST sensor.关键词：multitarget tracking;Date association;data fusion2|93|2更新时间：2025-12-08
- 摘要：Generalized expressions of equivalent edge crrrents for physical optics,fringe diffraction and total fields are derived eccording to the concept of the method of equivalent edge currents,and they can be re duced to those exprossions published.An optimum expression of equivalent edge currents for PO field is ob tained.The first,second and third order equivalent edge currents are derived based on the exact expression of non-uniform currents for a half-plane.Bistatic RCS of rhombic flat plat are calculated by the method presented in the paper,which is in good agreement with experimental results.关键词：The method of equivalent currents;Expression of equivalent edge currents;Bistatic RCS;Polygonal plates2|154|2更新时间：2025-12-08
- 摘要：Based on the wideband polarization radar system,after founding a model of target wideband polarization structure described by eigen-polarization,a new method of target classiffication based on fuzy dy namic feature extraction has been presented,and an effective recognition rate about five kinds of aircrafts is ob tained.关键词：polarization;Target polarization structure;Fuzzy feature;target recognition2|212|2更新时间：2025-12-08
- 摘要：Two-dimensional fractal function is used to model the fluctuation of the medium refractive in dex.The diffraction of plane wave by fractal phase screens is considered.Using Fresnel-Huygens principle,the diffracted field is obtained and the distribution of average diffracted intensity is calculated.The results show that fractal dimension and other descriptors of fractal phase screen control the distribution of diffracted intensity.关键词：Fractal function;Phase screen;Diffracted intensity2|124|1更新时间：2025-12-08
- 摘要：The Uniform Focusing is proposed to be employed to coherent signal subspace method（CSM）to estimate the direction-of-arrival（DOA）of wideband sources impinging of a known arbitrary geometry array.With the proposed method,the performance of the CSM is improved greatly in the computer simulations.关键词：Direction-of-arrival（DOA）;array signal processing;wideband signal2|229|6更新时间：2025-12-08
- 摘要：In this paper the reflection and radiation characteristics of circular dielectric rod antenna ex cited with HE11 mode are analyzed by a new method which combines the edge-element with mode-matching method.Unlike the convential method to treat the radiation as a“source-field”problem,in present approach,the dispersion characteristics of dielectric guided-wave structures are analyzed first,and then the radiation problem is transferred to the propagation problem of surface and space waves from the viewpoint of scattering,as a result,the analysis is tremendously simplified.Numerical results given here agree well with literature data,thus the effi ciency of present method is yerified.关键词：Edge-element;Mode-matching;Circular dielectric rod antenna2|152|2更新时间：2025-12-08
- 摘要：The electromagnetic wave propagation frequncy characteristic in layered media is studied in this paper.A new frequency model on EM wave propagation in lossy layered media is described.The frequency character on EM wave propagation in the lossy layered media is emulated by computer.The relationship about the media parametere and propagation characteristic is obtained.Some theoretical errors in the literature[5]are pointed out and redressed.关键词：电波传播;频率特性;有耗分层媒质2|109|1更新时间：2025-12-08
- 摘要：Modeling and Analysis of inverse scattering are very important for studies of the characteristics of radar targets.In this paper,according to the scattering mechanisms of radar targets in high frequency region,a general scattering model is described.A parameter estimation algorithm based on the state space method for the model is presented.The validity and effectiveness of the algorithin are proven theoretically and experimentally.关键词：radar;high frequency;scattering;parameters estimation2|330|5更新时间：2025-12-08
- 摘要：A new CFAR detector（OSTMGO）based on ordered statistics（OS）and trimmed mean（TM）is proposed in this paper.It takes the greatest value of OS and TM local estimations as a noise power estimation,and it also uses the automatic censoring technique proposed by[4].Under Swerling Ⅱassumption,the analytic expressions of Pfa, Pd and ADT of OSTMGO are derived.By comparison with other schemes,the results show that the detection performance of OSTMGO is good both in homegeneous background and in nonhomogeneous en vironment caused by strong interfering targets and clutter edges,particularly in clutter edges situation,the spike of false alarm rate of OSTMGO decreases an order of magnitude than that of GOSGO,while the sample sorting time of OSTMGO is less than half of that of OS.关键词：radar;detection;CFAR;Ordered statistics;Trimmed mean2|150|1更新时间：2025-12-08
- 摘要：The phenomenon of observation multiplicity for the phased-array radar is studied and a prepro cessing algorithm to eliminate the redundant observations is proposed.At first,the probabilities that redundant observations exist are derived.It is shown that these probabilities depend on signal-to-noise-ratio and the spacingbetween the adjacent beams.Second,a priori knowledge of the maximum number of observations to be merged and the maximum merging range is introduced to the pre-processing method.At last,the measurement’s error be fore and after mergence is calculated,and the performance of this method is compared with those methods without any limitations.关键词：phased array radar;Multiple target tracking;Observation multiplicity;Error mergence prob ability2|254|3更新时间：2025-12-08
- 摘要：A simplified efficient method for computing the distributed capacitance and inductance matri ces of multiconductor lines in multiayered dielectrics is delivered in thes paper.The conductors used may be ei ther finite or infinitsimal thickness.The key of this method is computing the approximate space-domain Green’s function of the multilayered media by means of spectral-domain Green’s function and using certain accelerating algorithm.Thus,the fast computing speed and sufficient accuracy can be obtained.The results from this method agree well with the references.关键词：Space-domain Green’s function;Spectral-domain Green’s function;Multiconductor interconnects2|113|3更新时间：2025-12-08
- 摘要：The mainbeam clutter spectra for airborne early warning（AEW）radar with non-side ways looking array（placed on aircraft turned in azimuth）are analyzed firstiy.In order to improve the system perfor mance near the mainbeam clutter region of this radar,the”filter-then-adapt”approach presented by Brennan is introduced and studied.For reducing the sampling and computational requirements,a modified space-time joint adaptive processing approach is proposed and analyzed.关键词：airborne early warning radar;space-time adaptive processing;Clutter suppression2|89|1更新时间：2025-12-08
- 摘要：This paper has proposed a new delay weighting method for estimating the position of gamma photon and its implementation.The conventional nuclear medical imaging of γ camera is realized through the es timation of single photon position and need a long the for exposition.Thus,the performance of the photon posi tion estimation should affect the quality of nuclear medical image.This paper presents the principle of space code/decode of delay weighting method,which provides the base for the digitization,miniaturization,modulariza tion and integration of the implementation of nuclear medical imaging devices.关键词：Single-photon position;Delay weighting;Space code/decode;Nuclear medical imaging2|29|5更新时间：2025-12-08
- 摘要：The data processor that performs the waverront reconstruction is one of the three components of a discrete adaptive oPtics（AO）system.It must satisfy the processing needs in AO system in real time.In this paper,on the basis of decomposition of wavefront reconstruction algorithn in which the concurrency is embed ded,a pipeline multiple SIMD（PMSTMD）parallel processing architecture is propsed.The hardware simulation experiment showe that the processor based on the PMSIMD architecture is capable of processing video images of 128×128pixels at 850 frames per second and the time delay is less than 1/4 period.关键词：Parallel processing architecture;Wavefront processor;Pipeline proceessing;Multiple SIMD architecture3|51|3更新时间：2025-12-08
- 摘要：Dimension Reduction Technique（DRT）combined with the Method of Lines（MoL）has been used to extract the capacitance of the via hole structure embedded in multilayered dielectric media with perforat ed reference planes.The numerical result given in this paper is in good agreement with that of Ansoft’software,but the CPU time is only a quarter of that of Ansoft’s and memory only one twentieth to one thirtieth of Ansoft’s.关键词：Multilayered dielectric;Perforated reference plane;Via hole;DRT;MoL2|41|0更新时间：2025-12-08
- 摘要：On the basis of measuring small-attenuation using noise temperature method,two new tentative plans for measuring small-attenuation in microwave waveguide devices by Y-factor method and noise temperature comparison method are presnted.关键词：Attenuation measurement;Noise temperature method;Y-factor method;Comparison method2|52|1更新时间：2025-12-08
- 摘要：本文提出一种机载预警侧视相控阵雷达抑制地物杂波的非自适应时空二维信号处理方法，即斜对消处理方法，该方法可分为整数型和内插型两种，计算机仿真结果表明，这两种方法虽各有优缺点，但都适用于实时处理，比以往各种方案都更简单．关键词：Spatial-temporal 2-D signal processing;Ground clutter suppression;Skew-canceling processing;Airborne warning radar;Side-looking phased array2|42|0更新时间：2025-12-08
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- 摘要：By resolving the differential operator for the wave equation in Generalized Orthogonal Coordi-nates（GOC）,two unidirectional wave equations are ohtained,and by using the central difference approximate method,Mur’s absorbing boundary condition of second order in GOC is presented in this paper.The results are compared with those in orthogonal and cylinder coordinates.关键词：Generalized orthogonal coordinates（GOC）;FDTD;Absorbing boundary condition（ABC）2|187|3更新时间：2025-12-08
- 摘要：A new fuzzy Kohonen clustering network is proposed which integrates Fuzzy c-Means（FCM）model as the fuzzy control mechanism into the learning rate and updating strategies of Kohonen network.It effec tively overcomes the shortcomings which occur during clustering network parameters are adjusted heuristically The numerical results show improved convergence as well as reduced clustering errors.关键词：cluster analysis;Fuzzy c-Means;Kohonen network;Lateral interactions2|179|2更新时间：2025-12-08
- 摘要：This paper presents an asymptotic procedure hased on transmission line analogy to determine the radiative characteristic of external loads loads composed of doubly periodic tapered microwave ab sorbers.The results are compared with numerical and experimental dats.When the period of the tapered absorber is less than 0.75 wavelength,the approsimate calculation is fairly well.关键词：External calibration load;Tapered microwave absorber;Transmission line analogy2|95|4更新时间：2025-12-08
- 摘要：The design method of mode selective directional coupler for use in TMon mode discrimination of high power microwave system is presented.Modifying the waveguide dimensions,installing multigroup coupling holes,determining the optimum number of coupling holes,etc are employed to inhance the directivity of coupled mode and the suppression of uncoupled modes.关键词：high power microwave;Mode discrimination;Mode selective directional coupler2|87|1更新时间：2025-12-08
- 摘要：Fast Hankel transform is applied to calculate Sommerfeld integral in this paper.It attains the value of integral rapidly and accurately by the convolution of input function with filter coefficients under the finite length of the filter and avoids the tedious numerical integration and computation of Bessel function,so the com putational efficiency and accuracy are improved greatly.关键词：Fast Hankel transform（FHT）;Sommerfeld integral;Filter coefficient2|713|12更新时间：2025-12-08
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