Dual-polarized slot-coupled microstrip antenna with very high isolation

Abstract

A wideband dual-polarized slot-coupled stacked microstrip antenna with very high isolation and low cross-polarization is presented. To improve isolation between two polarization ports, the stacked patches are excited by an open-ended and a T-shaped micros-trip lines both via two H-shaped slots placed in a “T” configuration. The measured isolation is better than 40.5 dB over the bandwidth from 8.8 to 9.8 GHz with cross-polarization level less than −28.5 dB. The measured VSWR⩽2 bandwidths reach 20.7% and 19.1% at the vertical and horizontal polarization ports, respectively. This antenna is suitable to be used as array elements in spaceborne synthetic aperture radars (SAR) and active phased array radars.