Low-profile, dual-polarized broadband antennas

The Foursquare and Fourpoint antennas developed by the Virginia Tech Antenna Group provide wideband performance and several practical advantages for commercial and military applications. Its features are a low-profile geometry, dual-polarization, compact radiating element size, making it ideal for use as an array element. The Fourpoint and Foursquare antennas have similar geometries, but the Fourpoint antenna provides significantly improved bandwidth within the same antenna size. The Foursquare and Fourpoint antennas provide bandwidth of 37% and 67% (Br=2:1) respectively for a VSWR/spl les/ 2 (referenced to 50 /spl Omega/). Both antennas have unidirectional patterns with HPBW of 60/spl deg/ and 80/spl deg/ in the E and H planes, respectively. The gain of both antennas is about 8-9 dBi over the operating frequency with a cross-pol level of the Fourpoint antenna less than 30 dB over the operating frequency range.