台阶反射面实现双频多波束天线收发等化的研究

双频多波束天线系统由于收发频段共用同一反射面,覆盖区内收发波束大小不一致.为了实现覆盖区内收发等波束,文章提出了一种新型的台阶反射面天线.通过对天线台阶高度的选取和台阶宽度的优化,可以使接收频率处每个台阶跳跃点与中心区在反射面等效口径处的相位相差180.,从而降低天线的口径效率,减小接收频率处反射面的电尺寸,最终实现了收发波束大小一致.为了进一步降低天线的副瓣电平,文章在接收频率处引入了馈源第一副瓣来照射反射面的台阶圆环,通过这一改进天线仍能实现收发等波束且获得了更低的副瓣电平.

Research on Dual-band Stepped-reflector Multiple Beam Antenna Which Can Realize the Equal Beam at Both Bands

Due to employing the same reflector at Tx and Rx bands, the dual-band multiple beam antenna cant realize the equal beam in the coverage at both bands. To realize the equal beam in the coverage, this paper presents a new stepped- reflector antenna. By selection of the height of the step and the optimization to the width of the step, the phase difference of 1800 can be achieved between the stepped-ring and the central portion of the reflector at the Rx band, which can lower the aperture efficiency, reduce the electric-size of the reflector and realize the equal beam at both bands. In order to realize the lower side-lobe level, the first side-lobe is introduced to the stepped-ring of the reflector at the Rx band. By this improvement, the equal beam at both bands can be realized and the lower side-lobe level can be obtained.