消交叉极化偏置双镜天线的分析和设计

偏置双镜天线,由于其结构不对称,交叉极化较难控制。成形时,涉及到一个非线性偏微分方程组,其精确解对任何预先给定的主镜口径场分布和馈源场分布不都存在。为此,本文提出了一个处理这一问题的近似方法,不仅提高了精度,还消除了天线的交叉极化分量。按此方法所设计的一个3米天线在12GHz 时的效率(计算值)为82%。

Analysis and Design of Offset Dual-reflector Antennas with Elimination of Cross-Polarization

It is difficult to control the cross-polarizations of offset dual-reflector antennas due to their non-symmetrical geometry.The antennas are shaped by solving a system of simultaneous nonlinear partial differential equations.Generally,the exact solution of this system is impossible in an arbitrarily predetermined aperture field distribution and feed pattern.An approximate method for solving this problem is presented in this paper.It not only increases the precision but also eliminates cross-polarization. The efficiency of a 3m antenna designed with this method at frequency of 12GHz is 82%(calculated values).