Patent ID: 7439897

Claim:
A method of digitizing an input signal, the method comprising the steps of: (a) selecting one of two non-disjoint bands B 1 or B 2 respectively representing staggered Nyquist regions that are the First Nyquist region for a basic sampling frequency FS 1 and the Second Nyquist region for an alternate sampling frequency FS 2 , where P/Q is a fraction between zero and one and FS 2 =(P/Q)(FS 1 ); (b) if band B 1 is selected, then: (b1) applying the analog input signal to a first anti-aliasing filter, of cutoff frequency FS 1 /2 less a guard band, to produce a first filtered signal in the band B 1 ; (b2) digitizing the first filtered signal at the sampling frequency FS 1 ; and (b3) storing the digitized values from step (b2) in a memory; else (c) if band B 2 is selected, then: (c1) applying the analog input signal to a second anti-aliasing filter, of cutoff frequency FS 2 /2 less a guard band to FS 2 less a guard band, to produce a second filtered signal in the band B 2 ; (c2) digitizing the second filtered signal at the sampling frequency FS 2 ; and (c3) algorithmically processing the digitized values from step (c2).