Analysis of the Reflector Antenna’s Feed Taper Level

Based on the experimental verification, this paper analyses the changes of antenna gain, sidelobe level, edge coverage gain and aperture efficiency when the taper level of the feed horn changes, and puts forward a range of optimal taper level. By introducing the concept of spatial attenuation of reflector antenna, a more accurate method to determine the taper level is given. Based on the value of the tapered level, it can provide quite favorable reference for different types of reflector characteristics in future design work.

I. Introduction

In the field of satellite communication, reflector antenna has been widely used because of its excellent high gain characteristics. For the whole antenna system, the feed is actually the core component that determines its performance. For a feed horn, its cross-polarization and equalization characteristics, as well as the phase center, standing wave ratio and taper level, all performance indicators have different degrees of influence on the antenna gain. In fact, the radiation pattern of the feed antenna has the greatest influence on the reflector antenna, because it controls the field distribution and aperture efficiency of the whole aperture. In order to achieve high aperture efficiency, it is necessary to match the feed pattern with the reflector, that is, to select the feed for appropriate irradiation of the reflector. The optimal aperture efficiency and gain of the antenna can be obtained by choosing the appropriate taper level[1].