CAJ | 학술논문

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 dB。测试频率的和方向图在±60°时的归一化增益均在-14~-20 dB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 dB,满足卡塞格伦天线对馈源设计的指标要求。
침대잡새격륜천선계통대궤원적요구,설계료일충Ka빈단쌍구쌍모궤원,가여X빈단궤원조합성체적교소적쌍빈단궤원。채용원배상적화차비교기결구,강저료쌍빈단궤원적체적,통과첨가과도계제、원주소정여금속조배판등설계,개선료쌍빈단궤원적성능。측시결과표명,재절대대관2 GHz범위내,S화구、E차구여H차구주파비균소우2,3개단구간적격리도균대우25 dB。측시빈솔적화방향도재±60°시적귀일화증익균재-14~-20 dB범위내,초급귀일화화방향도적대칭성교이상,차방향도적령치심도균소우-25 dB,만족잡새격륜천선대궤원설계적지표요구。
In order to meet the requirements of Cassegrain reflector antenna system for feed,a Ka-band du-al-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 tran-sitional 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 dB in the band-width of absolute 2 GHz. The normalized gain of sum patterns is between -20 dB and -14 dB at ±60°. The symmetry of primary normalized sum pattern is ideal. The zero depths of difference patterns are all be-low -25 dB. The test results verify that the designed feed meets the requirements of Cassegrain reflector antenna.