Single and dual-polarized wideband simultaneous transmit and receive antenna system

A shared antenna aperture for simultaneous transmit and receive (STAR) operating from 0.5 to 45GHz with isolation >50dB over the entire band is discussed. The proposed system utilizes four distinct band breaks: 0.5-2.5GHz, 2-7GHz, 619GHz, and 18-45GHz. The transmitting and receiving apertures of each band are designed, fabricated, and integrated on 46cm×46cm ground plane. A monostatic STAR system based on a lens-loaded cavity-backed four-arm spiral antenna is used to cover 0.5-2.5GHz band requirements. Other bands have dual-polarization capability and rely on physically displaced TX and RX antennas, engineered antenna patterns, and implementation of high impedance surfaces (i.e. bed of nails) to achieve desired isolation level. A dual-polarized Vivaldi array recessed in a cavity and quad-ridge horns are employed for the 2-7GHz and 6-45GHz bands; respectively.