Wideband Dual-Polarization Microstrip Patch Antenna Array for Airborne Ice Sounder

We present the design and realization of an antenna array based on cavity-backed microstrip patch antenna elements, with a relative operating bandwidth exceeding 20% at a return-loss level better than 15 dB. The antenna array of four elements did not show any compromise in bandwidth. It exhibited sidelobe levels better than 15 dB, with a gain of around 12 dBi. Excellent agreement was achieved between measurements and predictions for the designs of both the single element and the array. This antenna is part of the European Space Agency's airborne polarimetric P-band terrestrial ice sounder.