Patent ID: 6829311
Filing Date: 2004-12-07
Classification: H03D

Abstract:
A multiple stage frequency demodulator which demodulates an input frequency modulated (FM) signal and produces a bitstream output and the demodulator comprising:a conversion stage which receives said input signal and which produces a first intermediate complex signal representing the input signal; a mixer stage which receives said first intermediate complex signal from said conversion stage and said bitstream output as a feedback signal, said mixer stage producing a second Intermediate complex signal; and a phase quantizer stage which receives said second intermediate complex signal, said phase quantizer stage producing said bitstream output; whereinsaid mixer stage performs a discrete phase shift on said first intermediate complex signal, said phase shift being proportional to a value of said bitstream output; said phase quantizer determines a phase angle of the second intermediate complex signal; and said phase quantizer produces said bitstream output based on whether said phase angle lags or leads the phase of a predetermined signal.