宽角扫描偏置单反射面天线的面赋形设计

Shaping Design of Offset Single Reflector Antennas

为实现宽角扫描,对偏置单反射面天线进行了面赋形设计,减少了天线在扫描过程中所需馈源阵单元的数目,或者说在馈源阵单元数目给定的情况下,赋形工作降低了波束扫描给天线带来的增益损失。赋形工作中,首先根据反射面的初始数据,以双三次B样条函数逼近其初始形状,然后从各预定的馈源位置向反射面发出若干条射线,并采用几何光学(GO)求得这些射线经反射面反射后的方向,最后以这些反射线的方向与各对应扫描方向之间的偏差最小为优化目标,通过Powell方法对样条函数的插值数据点进行调节,最终确定了赋形反射面的形状。模拟结果表明了文中所述方法的可行性和有效性。

A reflector shaping design is made of offset single reflector antennas to realize wide-angle scanning, through which the element number of the feed array is decreased during the antenna scans, or given the number of the elements, the gain loss of the antenna induced by scanning can be reduced. In the process of the shaping, firstly, a two-dimensional cubic B-spline is used to approach the initial reflector surface based on its initial data. Secondarily, some rays emanated from every feed to the reflector are given, and the directions of the rays reflected by the reflector are obtained by the geometrical optics （GO） technique. Finally, taking the deviations between the directions of the reflected rays and the corresponding directions of the scanning to be minimal as the optimization objective, the interpolation data points for the spline function are adjusted through Powell method, by which the shaped reflector surface is obtained. Numerical simulation results are given to demonstrate the feasibility and effectiveness of the method presented in this paper.