A shallow-cavity UHF crossed-slot antenna

The shallow-cavity crossed-slot antenna is a UHF radiator designed primarily for use on a high-speed aircraft operating as the airborne terminal in a satellite-to-air communications link. The requirements, design analysis, and performance characteristics are described. The antenna's shallow profile makes it attractive either as a paste-on- or flush-mounted-type radiator. Near-hemispherical radiation coverage is provided.