A Very-High-Power High-Frequency Pulse Transmitter and Antennas. High-Power Extension of the High-Frequency Madre Radar

Abstract : The Madre system is a high-frequency radar employing crosscorrelation techniques and designed to have sufficient sensitivity to detect aircraft at ranges of 1500 miles, utilizing an ionosphere-reflection propagation path. Calculations have shown that both an antenna of high gain and a transmitter having an output of about 5 megawatts peak were required. A high-power rf amplifier, antenna, and duplexer add to the existing low-power Madre system. The 100-kw average high-power amplifier operates class B linear to reproduce a sine-squared pulse of 4.6 megawatts peak power in the 10 to 30 Mc frequency range. The antenna systems include an array of 20 corner reflectors operating from 13.5 to 27 Mc. Electrical steering of this array over a 60- degree sector is accomplished with variable-length transmission-line phase shifters. A tower-mounted, azimuth-positionable, two-bay corner-reflector antenna has also been built.