节点文献
超宽带天线频域和时域算法理论与应用研究
UWB Antenna’s Frequency and Time Domain Algorithm and Application Research
【作者】 吴锋涛;
【导师】 袁乃昌;
【作者基本信息】 国防科学技术大学 , 电子科学与技术, 2007, 博士
【摘要】 本文基于UWB冲激雷达、电子战中导引头和干扰机的应用需要展开对UWB天线的研究。工程上研制出平面阿基米德螺旋天线、角锥螺旋天线、印刷对数周期天线、平面TEM喇叭天线、平面印刷渐变开槽天线、高功率功分器和高功率TEM喇叭天线。理论上结合研制UWB天线需要,分别研究了频域算法-矩量法(MOM)和多层快速多极子(MLFMM)和时域算法.时域有限差分法(FDTD)。对于以矩量法为基础的MLFMM,由于不完善,不通用,所以本文推导出MLFMM的数学表述和数值求解表达式,完善了MLFMM的数学理论。提出了MLFMM的高效求解方法,开发出电磁快速算法软件包,并用软件包仿真了金属球、介质球、导弹模型、F117隐身飞机,三维转台,抛物面天线和天线罩。研究了ILU和稀疏近似逆预条件算法的加速收敛性能。由于FDTD比较成熟,具有广泛的通用性,因此,本文以应用为主。根据干扰机和导引头应用需要,从频域来研究平面阿基米德螺旋天线、锥台螺旋天线和印刷对数周期天线。采用矩量法和MLFMM来分析平面阿基米德螺旋天线、角锥螺旋天线和天线罩对天线性能的影响。对数周期天线采用FDTD分析,提出了一种高效快速的FDTD比相仿真算法。根据无载波超宽带冲激雷达工程应用需要,本文从时域研究用于发射的平面TEM喇叭天线和用于接收的平面印刷天线,并运用FDTD来分析,提出了一种FDTD仿真UWB天线时域特性的算法。在外场测量单个天线和其阵列的时域方向图和时域扫描特性,阐述UWB天线时域方向图和普通窄带天线的不同点,采用能量方向图和峰值方向图来衡量天线的方向性。利用研制的UWB收发天线阵列组成冲激雷达外场实验系统,对低空隐身目标进行探测研究,并对实验数据的基本规律进行了分析。由于高功率源比固态源在输出功率上大2-4个数量级,所以把高功率源应用于远距离目标探测具有诱人的前景。为了应用高功率源进行冲激雷达外场目标探测,研制出高功率功分器和高功率天线阵,对高功率源的外场目标探测做了初步探索研究,外场探测表明高功率脉冲源基本可用于目标探测,但需改善源的稳定度,才能相干积累,提高探测距离。
【Abstract】 UWB antenna was studied to meet the need of impulse radar,seeker and jammer in electronic warfare.In engineering,planar Archimedes spiral antenna,conical spiral antenna,printed log periodic dipole antenna,planar TEM horn antenna,planar printed tapered slot antenna,high power divider and high power TEM horn antenna were developed.In theory,method of moment(MOM) and finite-difference time-domain method(FDTD) were studied on UWB antenna.The multilevel fast mutipole method (MLFMM) based on MOM is under developed.So math formula of MLFMM was derived initially and numeric formula was provided.High efficiency MLFMM codes were developed and metal sphere,dielectric sphere,missile model,f117 fighter, 3-dimensional positioner,parabolic antenna and radome were simulated by the codes. The convergence performance of incomplete LU preconditioner and sparse approximate inverse preconditioner was studied.FDTD was directly used to simulate UWB antenna, because it is relatively simpler and maturer than other methods and has wide range of application.Planar Archimedes spiral antenna,conical spiral antenna and the printed log periodic dipole antenna,were researched in frequency domain on the demand of jammer and seeker.MOM and its accelerated algorithm MLFMM were introduced to simulate the planar Archimedes spiral antenna,conical spiral antenna and radome with antenna. FDTD was used to analyze the printed log periodic dipole antenna and high efficiency FDTD algorithm for comparing phase simulation was invented.The planar TEM horn antenna for transmitting signals and planar printed tapered slot antenna for receiving signals were studied on the need of impulse radar.FDTD was introduced to analyze the antenna and its pattern was measured in outdoor.The difference between UWB antenna in time domain and narrow band antenna in frequency domain was prsented.Energy pattern and peak value pattern were introduced to weigh the antenna’s directivity.The experiment system of impulse radar was made using the UWB antenna we developed and low level stealth target was detected.The law of experiment data was analyzed.The application of high power source in long range target detection is attractive for its output power is about 10~2-10~4 times of solid source.So high power divider and antenna array were developed to use high power source in detecting outdoor target.The first step of target detection using high power source in the open air was carried out. The experiment shows the high power source can be used in target detection,however, to improve the detection range,the stability of waveform should be improved to accumulate target echo.