Radar exciter local oscillator phase lock acquisition control circuit

摘要

A phase lock acquisition control circuit for the local oscillator (LO) of a radar exciter. The control circuit includes a programmable logic array, a microsequencer and a counter employed as a divide-by-eight circuit which supplies a clock reference for the control circuit. The counter in turn is clocked by a crystal based oscillator also used as the reference for the exciter phase lock loop. The marker filter and zero beat detector provide frequency location information to the control circuit. The control circuit controls a ramp generator circuit which in turn can drive the phase lock loop VCO during acquisition.