Measuring the frequency of signals in a receiving device with compression of the input frequency range

Rapid determination of carrier frequencies in a modern complex electromagnetic environment is a general problem. To resolve frequency ambiguity during digital signal processing in radar signal detection and frequency measurement, a method of input frequency range compression using sample-and-hold (S/H) units in a receiver is proposed. A proof is presented for a theorem stating that in a two-channel receiver employing S/H units for input frequency range compression, given an irrational ratio of the Nyquist frequencies defining the post-compression operating bands, there exists a unique pair of integers satisfying the condition for reconstructing the input signal frequency from the measured post-compression frequencies. Based on this proof, an algorithm for measuring the input signal frequency is developed using the intersection of frequency sets defined by the compression parameters and the output signal frequencies. Finally, a block diagram of the receiver architecture with input frequency range compression and an ambiguity resolution algorithm for detected radar signals are proposed.