Abstract: Antenna elements include a metallic square ring patch and a metallic square ring slot to transmit or receive radio frequency (RF) signals. The antenna elements use several dielectric layers that are separated by a low-dielectric foam layer upon which the square ring patch is positioned. The antenna elements may be arranged into an antenna array that is tunable to collectively generate or receive RF signals to and from airborne and mobile vehicles with an agile, electronically scanning antenna array beam, with no moving parts. The antenna array includes a top section to communicate RF signals; a bottom section to generate a desired RF signal; and a foam layer between the top and bottom sections to separate the ring patch from the ring slot. High isolation between the top section and the bottom section allows the antenna elements to be used in higher gain and high-power arrays without adverse feedback issues.

Abstract: Antenna elements include a metallic square ring patch and a metallic square ring slot to transmit or receive radio frequency (RF) signals. The antenna elements use several dielectric layers that are separated by a low-dielectric foam layer upon which the square ring patch is positioned. The disclosed antenna elements may be arranged together in an antenna array that is tunable to collectively generate or receive RF signals. In particular, the antenna array functions as a 256-element transmit/receive half-duplex antenna, operating in transmit or receive mode for half the time. The antenna array includes a radiator block, a transmit/receiver (T/R) amplifier block, a beamformer block, and a distribution network block.