改善单偏置天线交叉极化劣化的C-band馈源

Type of C-band feed suitable for improving the cross polarization degradation of single-offset parabolic reflector antenna

描述了用波纹喇叭中的 HE_(21)模抵消单偏置抛物面天线非对称平面交叉极化分量的基本原理,介绍了 TE_(21) 模激励器、波纹喇叭的设计方法和展宽馈源抑制单偏置天线交叉极化分量频带宽度的设计方法,给出了 C 波段 2．4m 单偏置抛物面天线的实验测试数据,单偏置抛物面天线非对称平面交叉极化电平改善了10dB,抑制交叉极化分量的馈源相对工作频带宽度大于8％。这种 TE_(21)模激励技术和与主模 TE_(11)模相位差的调整方法,对馈源的电压驻波比几乎没有影响。

The fundamental mechanism is presented in this paper for the approach to cancel the cross polarization component produced by the asymmetry of single-offset parabolic reflector antenna in the asymmetrical plane using HE21 mode of corrugated horn. The design methods are also introduced for the TE12 mode generator and corrugated horn to be able to reject cross polarization in the asymmetrical plane of offset parabolic reflector antenna. The test data shows that for a C-band offset parabolic reflector antenna with 2.4 m in diameter, 10 dB improvement is realized in the cross polarization in the asymmetrical plane, the relative bandwidth is larger than 8 % in which cross polarization improvement better than 10 dB can be achieved. It is shown that either the technique for generating TE21 mode or the method for adjusting the phase difference between the primary mode TE11 and TE21 has almost no effect on the VSWR of the feed.