论文部分内容阅读
抛物反射面天线,在雷达及微波通信中是广泛应用的天线。近年来,由于卫星通信与卫星电视转播的发展,使它的应用日益广泛。抛物面天线由旋转对称的旋转抛物面(反射面)与馈源组成。由于反射面是固定的旋转抛物面,天线的性能在很大程度上取决于馈源的性能。所以,为了改善和提高抛物面天线的性能,近年来天线工作者把相当多的注意力都放在馈源的研究与改进上,要求馈源与反射面密切匹配。也就是说,作为反射面天线的馈源,要求它能在天线反射面的口面上形成一个适当的场分布。这种分布使得天线在某个频带内,在某一给定的旁瓣电平的前提下能得到最大的增益。这除了在设计天线时正确选择馈源的波束宽度与之相配外,还要求馈源的辐射方向图旋转对称、交叉极化激励得要低、旁瓣与后瓣电平要低,在 E 面与 H 面的相位中心要重合,再有馈源与其支架结构对天线的遮挡要小。
Parabolic reflector antennas are widely used antennas in radar and microwave communications. In recent years, due to the development of satellite communications and satellite television broadcasting, its application has become increasingly widespread. The parabolic antenna consists of a rotationally symmetric rotating parabola (reflector) and feed. Since the reflective surface is a fixed, rotating parabola, the performance of the antenna depends very much on the feed’s performance. Therefore, in order to improve and improve the performance of parabolic antennas, antenna workers have put a lot of attention on the research and improvement of feeds in recent years, and require that the feed source closely matches the reflective surface. That is, as a feed to the reflective antenna, it is required that it form a proper field distribution on the face of the antenna reflective surface. This distribution allows the antenna to gain maximum gain in a certain frequency band with a given sidelobe level. In addition to correctly selecting the beam width of the feed to match the antenna design, the radiation pattern of the feed is also required to be rotationally symmetric, the cross-polarization excitation should be low, the sidelobe and backlobe levels should be low, And H-phase center to coincide, and then feed and its support structure of the antenna to cover the smaller.