宽带双波段双极化共口径SAR天线设计

 介绍了一种应用于合成孔径雷达(SAR)的X和S双波段双极化(DBDP)共用口径宽带天线阵的设计与测试结果.针对以往同类天线低频百分比带宽明显较高频窄的缺点,设计中采用了三谐振技术来展宽低频波段的带宽;并综合采用多种方法以改善两个波段的极化隔离度.经实测,样阵X和S波段的带宽(VSWR≤2)分别达到13.1%和11%;带内阵列隔离度优于37dB,单元隔离度优于28dB;阵列方向图与理论均吻合很好,主瓣内交叉极化优于27dB;X波段扫描能力达±27°.

Design of Broadband Dual-Band Dual-Polarized Share-Aperture SAR Antenna

A broadband dual-band dual-polarized(DBDP) shared-aperture array operating at X-and S-bands for the synthetic aperture radar(SAR) application is presented.Tri-resonance is introduced in the lower frequency element to broaden its intrinsic narrower bandwidth.Furthermore,several methods are employed to enhance the polarization isolation in both bands.VSWR≤2 bandwidths of 13.1% and 11% are measured in X-and S-band,respectively,where in-band array isolation and element isolation are better than 37dB and 28dB.The measured radiation patterns match well with the theoretical ones while the cross-polarization level is suppressed under-27dB within mainlobe;the X-band scan ability of ±27° is also confirmed by the measurement.