Pulse-repetition frequency discriminator (PRFD) for tracking radar signals

Abstract

1. In a pulse-repetition frequency discriminator, the combination compris: g A. a pulse generator for generating pulses at a predetermined reference frequency, B. a gate generator coupled to said pulse generator and being responsive to the generated pulses to generate a gate signal having a width of a predetermined percentage of the repetition period of the predetermined reference frequency, C. ramp generator means coupled to said gate generator for converting said gate signal into a triangular shaped signal, D. a normally closed gate circuit coupled to said ramp generator means and to an input terminal adapted to receive radar pulses of interest and being responsive to received radar pulses having a frequency within said gate signal to pass a portion of said triangular shaped signal, E. circuit means having an input coupled to said normally closed gate circuit and having a reference voltage equal to one-half the amplitude voltage of said triangular shaped signal and having an output coupled to said pulse generator for feeding a corrective voltage proportional to the difference between the amplitude of the output voltage passed by said normally closed gate and said reference voltage to said pulse generator to change the PRF of said pulse generator in a direction to reduce said corrective voltage to zero.

Dependencies are inferred from the claim text.