关键词: 宽带, 高隔离度, 双波段, 双极化, 共用口径, 微带天线阵, 非整数频率比, 合成孔径雷达天线

Abstract: 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.

Key words: broad band, high isolation, dual-band, dual-polarization, shared aperture, microstrip array, non-integral frequency ratio, SAR antenna