Circuit for accurately measuring phase relationship of bpsk signals

Abstract

The disclosed system measures the phase relationship of first and second K signals received at a pair of receiving antennas. The antennas are connected to respective first and second converting circuits which convert the received signals into first and second CW signals. Each CW signal is subjected to chirp-Z processing so as to convert the first and second CW signals into first and second chirp-Z transforms, which are narrow pulses. Then, the phase relationship of the first and second narrow pulses is detected, so as to thereby detect the phase relationship of the first and second received BPSK signals. That phase information can be used, for example, to calculate the angle-of-arrival (AOA) of the received BPSK signals. Advantageously, each converting circuit includes a series connection of a frequency-doubling circuit, a bandpass filter, and a circuit for dividing frequency by two, in that order. A switching arrangement is provided which is operable for applying the outputs of the converting circuits to the phase detecting circuit only when the received signals are BPSK signals.