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Solving multi-object radar cross section based on wide-angle parabolic equation method

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Journal of Systems Engineering and Electronics 2006年第4期17卷 722-724页

作者： Huang Zhixiang wu Qiong wu xianliang The Key Lab of Ministry of Education of Intelligent Computing & Signal Processing Anhui Univ. Hefei 230039 P. R. China

Based on a Pade approximation, a wide-angle parabolic equation method is introduced for computing the multiobject radar cross section （RCS） for the first time. The method is a paraxial version of the scalar wave equation, which solves the field by marching them along the paraxial direction. Numerical results show that a single wide-angle parabofic equation run can compute multi-object RCS efficiently for angles up to 45 ° . The method provides anew and efficient numerical method for computation electromagnetics.

关键词： parabolic equation method Pade approximation radar cross section paraxial direction.

A Miniaturized Bandwidth Reconfigurable Bandpass Chip Filter with Semi-lumped Topology and GaAs pHEMT Technology

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Chinese Journal of Electronics 2021年第1期30卷 192-198页

作者： LI Linqing ZHU Haoran NING Xingyu LI Zunwen wu xianliang Key Lab of Intelligent Computing and Signal Processing Ministry of Education Anhui University

A miniaturized reconfigurable bandpass chip filter with semi-lumped topology and Gallium Arsenide pseudomorphic High electron mobility transistor（GaAs pHEMT） technology is proposed. Semi-lumped topology is employed to instead the traditional lumped inductor with microstrip transmission line, which can reduced the size of the tunable filter significantly. Three-order series and shunt resonated bandpass filter is implemented with shorted stubs and metal-insulator-metal capacitors. Two transmission zeros are introduced with the series resonator and the shunted GaAs FET. By tuning the gate bias circuit of the FET, the capacitance of the series resonator is changed and the bandwidth of the filter is adjusted correspondingly. An equivalent circuit model is developed to interpret the mechanism of the proposed filter circuit. A reconfigurable on chip filter sample operated at 10 GHz is fabricated to validate the design. Two fractional bandwidth of 14.3% and 23.5% are tuned with bias voltage of the FET, while insertion loss of 2.4 d B and 2.2 d B are observed with the filter, respectively. The area of the chip filter is 0.86 × 0.96 mm2and is equivalent to an electrical length of 0.08 × 0.09λg2at center frequency. Measurement results agree well with the simulation ones.

关键词： gallium arsenide tunable filter transmission zeros equivalent circuit model resonator filters shunted FET III-V semiconductors miniaturized bandwidth reconfigurable bandpass chip filter MIM devices microstrip transmission line chip filter sample shunt resonated bandpass filter metal-insulator-metal capacitors semilumped topology loss 2.4 dB Gallium Arsenide pseudomorphic High electron mobility transistor technology insertion loss filter circuit integrated circuit design GaAs integrated circuit manufacture frequency 10.0 GHz pHEMT technology microwave filters loss 2.2 dB HEMT integrated circuits series resonator miniaturized reconfigurable bandpass chip filter band-pass filters

Staggered Grid Scheme for the FFT-Based Methods

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Chinese Journal of Electronics 2019年第5期28卷 1066-1072页

作者： XIE Jiaye KONG Weibin PANG Lili SONG Weiju HUANG Zhixiang wu xianliang Industrial Center Nanjing Institute of Technology State Key Laboratory of Millimeter Waves College of Information Engineering Yancheng Institute of Technology Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University

A staggered grid scheme is proposed to reduce both the total memory requirement and the CPU time of generating the corrected near matrix in the FFTbased methods. Two sets of Cartesian grids are used to project the source points and the field points, *** proposed method does not lower the efficiency of computing far matrix-vector products, compared with the traditional uniform Cartesian grid scheme. Some numerical experiments are provided to demonstrate both the correctness and the efficiency of the proposed method.

关键词： Green’s function Singularity RFG-FFT Staggered grid scheme Corrected near matrix

EXTRACTION OF NATURAL FREQUENCY FROM MEASURED LATE-TIME TRANSIENT RESPONSES WITH RATIONAL MINIMAX APPROXIMATION IN FREQUENCY DOMAIN

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EXTRACTION OF NATURAL FREQUENCY FROM MEASURED LATE-TIME TRAN...

Analysis of Courtyard Plant Landscape Design

1998 International Conference on Microwave and Millimeter Wave Technology

作者： Jiao Dan Xu Shanjia wu xianliang Dept.of Electronic Eng.& Information Sci. Univ.of Science & Technology of China Dept.of Electronic Eng.& Information Sci. Anhui University

ISBN: (纸本)0780343085

＜正＞A simple technique is presented for extracting natural frequencies from measured late-time transient *** method first applies rational mini-max approximation to the Fourier transform of the even extension of a transient response,then obtains natural frequencies directly from the zeros of the denominator polynomial of the optimum rational function. The effectiveness of the method is verified with a synthetic transient response and a measured response of a conducting *** results from the present method for the synthetic tfansient response are compared with those from constrained E-pulse technique （CET） and genetic algorithm technique（GAT）.It indicates that the present method avoids an initial guess,overcomes the tendency to get stuck in local minima and requires much less computer effort than the *** addition,unlike the GAT,it generally guarantees convergence and is insensitive to any parameter.

关键词： transient response convergence of numerical methods minimax techniques poles and zeros radar theory Fourier transforms natural frequency extraction late-time transient responses rational minimax approximation frequency domain Fourier transform denominator polynomial optimum rational function conducting sphere convergence radar target identification

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Journal of Landscape Research 2013年第4期5卷 29-30,34页

作者： wu xianliang Hezhou University

Plant landscaping in courtyard design was studied from four perspectives of building, water, road, garden setting and plant landscaping. Landscape designs in Guangzhou Baiyun Hotel, the Humble Administrator's Garden (Suzhou), and bamboo pathway of Small Yingzhou in the West Lake (Hangzhou) to improve scientific and artistic properties of plant landscaping, and develop economic, social and ecological effects of garden green spaces to the most.

关键词： Plant landscaping Greening Design

基于CZT的机载并行双站斜视SAR成像算法

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航空学报 2010年第4期31卷 825-830页

作者：武拥军吴先良安徽大学计算智能与信号处理教育部重点实验室安徽合肥230039 合肥电子工程学院信息系安徽合肥230037

建立了机载并行双站斜视合成孔径雷达(SAR)的几何模型,给出了雷达回波的数学表达式,推导了它的二维频谱并对其特点做了分析。在二维频域内,先用聚焦函数对观测场景中心的点目标做精确成像,然后用Chirp-Z变换(CZT)校正中心点两侧目标回... 详细信息

建立了机载并行双站斜视合成孔径雷达(SAR)的几何模型,给出了雷达回波的数学表达式,推导了它的二维频谱并对其特点做了分析。在二维频域内,先用聚焦函数对观测场景中心的点目标做精确成像,然后用Chirp-Z变换(CZT)校正中心点两侧目标回波的距离徙动,再通过方位向逆傅里叶变换得到了雷达图像。该算法利用了CZT能够处理非线性调频信号的特点,简化了处理过程,提高了计算效率和成像精度。仿真实验验证了这种基于CZT的新算法在处理并行双站斜视SAR数据时的有效性。

关键词：合成孔径雷达二维频谱聚焦函数 Chirp-Z变换成像算法

Study on the Gain Material with Four Energy Level Model Using FDTD Method

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Optics and Photonics Journal 2013年第2期3卷 15-20页

作者： Hui Xue Zhixiang Huang xianliang wu 1Key Laboratory of Intelligent Computing and Signal Processing Anhui University Hefei China 2Department of Physics and Electronic Engineering Hefei Normal University Hefei China Key Laboratory of Intelligent Computing and Signal Processing Anhui University Hefei China

A faster numerical method based on FDTD for the four energy level atomic system is present here. The initial conditions for the electrons of each level are achieving while the fields are in steady state. Polarization equation, rate equations of electronic population and Maxwell’s equations were used to describe the coupling between the atoms and electromagnetic wave. Numerical simulations, based on a finite-difference time-domain (FDTD) method, were utilized to obtain the population inversion and lasing threshold. The validity of the model and its theory is confirmed. The time, which we can observe the lasing phenomenon, is much shorter in our new model. Our model can be put into using in large scale simulations in mutiphysics to reduce the total simulated time.

关键词： Finite-Difference Time-Domain Gain Material Lasing

The New Method for Calculating Poles of a Scattering Object

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Journal of Systems Engineering and Electronics 1997年第4期8卷 1-6页

作者： wu xianliang, Jiao Dan & Wang Liangzhiwu xianliang, Jiao Dan & Wang Liangzhi Department of Electrical Engineering and Information Science, Anhui University, Hefei 230000, P. R. China Peng Zhongqiu Beijing Institute of Information Remote Sen Department of Electrical Engineering and Information Science Anhui University Hefei 230000 P. R. China Beijing Institute of Information Remote Sensing 100076 P. R. China

The natural resonances (poles) of a scattering object are important for the target identification. A new method for calculating poles of a scattering object is proposed in this paper. It is shown that the zeros of the Fast Fourier Transform of the integral kernel function are the poles of the scattering object. As an example, the poles of a thin wire conductor are obtained with high precision in very short time by using this method.

关键词： Target identification Fast Fourier transform.

基于辛几何理论的非均匀媒质中电磁波传播问题的研究

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电子学报 1999年第9期27卷 66-69页

作者：付彪吴先良李世雄安徽大学电子工程与信息科学系合肥230039 安徽大学数学系合肥230039

本文提出了一种利用辛几何理论求解非均匀媒质中电磁波传播问题的新方法．首先引入新的波向量空间与原来的物理空间共同构成辛空间，将物理空间中波的传播问题提升为辛空间中的Ｌａｇｒａｎｇｅ子流形的问题，并通过适当的投影变换可... 详细信息

本文提出了一种利用辛几何理论求解非均匀媒质中电磁波传播问题的新方法．首先引入新的波向量空间与原来的物理空间共同构成辛空间，将物理空间中波的传播问题提升为辛空间中的Ｌａｇｒａｎｇｅ子流形的问题，并通过适当的投影变换可以处理电磁波在非均匀媒质中传播的焦散问题．

关键词：辛几何理论波动方程非均匀媒质电磁波传播