NOVEL-APPROACH TO THE DESIGN OF I Q DEMODULATION FILTERS/

A novel filter design approach to digital I/Q demodulation is proposed . Two possible realisations are presented using this approach. The fir st one is based on the highpass filter method which is suitable for B less-than-or-equal-to f0 and while the other realisation is based on t he lowpass filter method suitable for B less-than-or-equal-to 2f0, whe re B and f0 are the IF signal bandwidth and the IF frequency, respecti vely. Both new realisations maintain the advantages of an earlier lowp ass approach such as zero DC offset, matched channel frequency respons es, and good performance over a wide bandwidth. At the same time, the new highpass filter realisation method possesses higher computational efficiency than other wideband approaches reported in the literature.