Simple broadband dual-polarized aperture-coupled microstrip antenna

This paper presents a simple broadband dual-polarized microstrip antenna with only three layers. The input impedance bandwidth (VSWR<2) of 25% is achieved with the double resonance technique, in which the resonant frequencies of the patch and the coupling slot are tuned near to each other. Proper positioning of the coupling slots and the use of a thin, medium permittivity substrate results in high isolation (>40 dB) between the ports and thus acceptable cross polarization (better than -20 dB). The geometry, return loss, and the isolation of a single antenna element and the radiation pattern of a four-element linear array are presented. These antennas were designed for the European DBS-band 10.70-12.75 GHz.