Abstract: Systems and methods provide a HESA (“High Efficiency Sensitivity Accuracy”) direction-finding (“DF”) antenna system that operates over a range from 2 MHz to 18 GHz. The system may include components such as a dipole array, a monopole array, and an edge-radiating antenna, each component being responsive to a specific frequency range. The system may further include biconical flares that optimally terminate a freespace wave in a small aperture.

Abstract: Systems and methods provide a HESA (“High Efficiency Sensitivity Accuracy”) direction-finding (“DF”) antenna system that operates over a range from 2 MHz to 18 GHz. The system may include components such as a dipole array, a monopole array, and an edge-radiating antenna, each component being responsive to a specific frequency range. The system may further include biconical flares that optimally terminate a freespace wave in a small aperture.

Abstract: A repeater station having circularly polarized antennas. A diamond panel antenna and a panel antenna are positioned in a back-to-back relationship. Each antenna is circularly polarized. The antennas use "tunnel technology" for isolating the antennas. A chassis forming a recessed portion is provided. A dielectric board is inserted into the recess. Patch elements mounted on a board are inserted into the recess and connected to the dielectric board. The width of the boards are such that a "tunnel" is formed about the periphery thereof. Absorber material is then inserted into the tunnel around the boards. A radome is placed over the recess enclosing the boards and elements.