【摘要】 针对卡塞格伦天线系统对馈源的要求,设计了一种Ka频段双口双模馈源,可与X频段馈源组合成体积较小的双频段馈源。采用圆环状的和差比较器结构,降低了双频段馈源的体积,通过添加过渡阶梯、圆柱销钉与金属调配板等设计,改善了双频段馈源的性能。测试结果表明,在绝对带宽2 GHz范围内,S和口、E差口与H差口驻波比均小于2,3个端口间的隔离度均大于25 d B。测试频率的和方向图在±60°时的归一化增益均在-14~-20 d B范围内,初级归一化和方向图的对称性较理想,差方向图的零值深度均小于-25 d B,满足卡塞格伦天线对馈源设计的指标要求。更多还原

【Abstract】 In order to meet the requirements of Cassegrain reflector antenna system for feed,a Ka- band dual- aperture dual- mode feed is designed in this paper,which can be constituted a dual- band feed with an X- band feed. An annular comparator structure is designed to reduce the size of dual- band feed.The transitional steps,cylindrical pins and adjustment board are used to improve the performance of dual-band feed. Test results show that the voltage standing wave ratio( VSWR) of S sum port,S difference port and H difference port are all below 2,the isolation among these three ports are all larger than 25 d B in the bandwidth of absolute 2 GHz. The normalized gain of sum patterns is between- 20 d B and- 14 d B at ±60°. The symmetry of primary normalized sum pattern is ideal. The zero depths of difference patterns are all below- 25 d B. The test results verify that the designed feed meets the requirements of Cassegrain reflector antenna.更多还原