EHF antenna ground terminal feed techniques

Antenna configurations and their feed subassemblies have been evaluated with regard to their use in high-performance and low-cost tactical and strategic systems to support DSCS III EHF (extremely high frequency) upgraded ground communications terminals. Specific objectives were to (1) select optimum configurations for the tactical and strategic antennas, (2) establish the antenna and feed requirements for each of the strategic and tactical terminal implementations, and (3) produce a design for an equivalent 8-ft-diameter antenna, including a frequency selective surface (FSS) subreflector and feeds for the 5 kW circularly polarized transmitter and monopulse tracking receiver subsystems. The symmetrical Cassegrain antenna was found to yield the best performance at the least cost. The antenna may be used with both common-aperture or dual-separate-aperture transmit/receive feeds in conjunction with FSS reflectors. A dual-aperture, monopulse-tracking, high-transmit-power EHF feed system has been designed, fabricated, and tested. Performance is excellent at the transmit band and marginally acceptable at the receive band