Smart AGC: a new anti-jam device for military satellite system

An antijam device based on substitution of a more efficient automatic gain control (AGC) function into the front end of a transponder is described. Smart AGC discriminates between jammed and unjammed signals based solely on amplitude of the incoming signals. The key to operation of smart AGC is a broadband power measurement of the composite input signal which is then used to control a nonlinear amplifier/limiter characteristic, preventing the satellite high-power amplifier from saturating. The author describes the basics of smart AGC operation, and presents results obtained with a simulator developed by Comsat Systems Division. Implications for improved performance of future UHF and X-band satellites are discussed.<
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