Abstract: A phase comparator has additional circuitry for correcting nonquadrature error during operation of the comparator. The phase comparator has a 90 degree power divider which receives a reference signal input and produces two reference outputs, one shifted 90 degrees out of phase with the other. The phase comparator also has a zero degree power divider which receives a return signal, such as a reflected signal of a radar transmitter unit. The outputs of the power dividers are applied to mixers and filters to result in an I video output whose frequency is the difference between the reference and signal input frequencies, and a Q video output which is identical in frequency but shifted 90 degrees. The correction circuit includes a frequency trap connected to the reference input and tunable about a center frequency of approximately the third harmonic of the fundamental reference frequency.

Abstract: A radar correcting system has features for providing a corrected radar receiver reflection to a Doppler process unit. The corrected receiver pulse accounts for variances in phase, amplitude and frequency of the transmit pulses. The system has a phase detector that detects the phase difference between a stable oscillator and the transmit signal, providing a complex video or real and imaginary outputs. An operator that will normalize the transmit pulse is determined. The operator is applied to the reflections received by the receiver antenna to remove from the reflections any vagaries due to varieties in the transmit pulses. The data proceeding to the processor deals only with the objects causing the radar reflection.