Method of processing a high frequency signal containing multiple fundamental frequencies

Abstract

A method of processing a high frequency signal containing at least two different fundamental frequencies F and F and their harmonic components in order to extract at least one harmonic component of each of the two fundamental frequencies comprises sampling the signal at two sampling frequencies CK =F (M /N ) and CK =F (M /N ), where M and N are a first pair of integers having no common factor and M and N are a second pair of integers having no common factor. The sample values resulting from sampling at CK are stored cyclically in a set of M memory locations such that the nth sample value is stored cumulatively in the remM [n]th memory location, and the sampled values resulting from sampling at CK are stored cyclically in a set of M memory locations such that the nth sample value is stored cumulatively in the remM [n]th memory location. The sampling is continued at each sampling frequency CK and CK until sufficient sample values have been stored in each memory location of the corresponding set M or M to substantially average out the other fundamental frequency(s) and its/their harmonic components. Finally, a Fourier analysis of the sample values in each set M and M of memory locations is performed to extract the said at least one harmonic component of each fundamental frequency F and F