不同参数超宽带反射面天线系统辐射特性

在超宽带反射面天线设计中,首要问题是馈电天线的方向图与反射器匹配。以往在频域上对反射面天线的研究发现,当馈源天线方向图给出约-11 dB的边缘照射时,反射面天线可实现其最佳性能。在参数化模拟了作为馈源的透射电子显微镜(TEM)喇叭天线方向图特性的基础上,根据反射面天线的频域设计准则,相应地加入合适的超宽带反射面天线,对其远场辐射特性进行模拟计算。为了获得尽可能大的远场辐射场,采用计算机仿真技术(CST)数值模拟软件,在0 GHz~1 GHz频率范围内模拟了以不同参数TEM喇叭天线作馈源的超宽带反射面天线的远场辐射特性,并在时域上对其结果进行分析。模拟结果表明,由于其相位中心的不确定性,作为馈源的TEM喇叭天线无法与反射面天线完全匹配,其沿着反射面天线主轴移动时产生的反射面口径场相位和幅度的变化影响着远场辐射场的变化,TEM喇叭天线的遮挡效应也不容忽视。

The radiated characteristics of UWB reflector antenna with different parameters

In the design of the Ultra-wideband(UWB) reflector antenna,the most important problem is the matching between the radiation pattern of feeding antenna and the reflector.A rule in designing the reflector antenna in the frequency domain is that the radiation of the feeding antenna on the edge of the reflector is about-11 dB.The radiation patterns of Transmission Electron Microscopy(TEM) horn are simulated in different parameters,then some proper UWB reflector antennas are added and simulated to obtain higher amplitude of the far-field radiation by Computer Simulation Technology(CST) in 0 GHz-1 GHz.In the end,the simulation results are analyzed in the time domain.It is concluded that the radiation pattern of the TEM horn cannot match up with the reflector as the phase center of the TEM horn is uncertain,and when the TEM horn moves along the central axis,the field of the reflector surface changes,which leads to the change of the far-field radiation.At the same time,the effect of the shade of TEM horn should not be neglected.