Jack Smith wrote:
> If the signal is band limited, can't you simply subsample at a
> divisor of the IF rate, thereby doing the mixing and A/D conversion
> in one step.

Yes, that's actually a valid technique for signals known not to contain
frequencies below a specific limit.  This is how some sampling oscilloscopes
can display GHz signals.

One way to look at it is you're sampling a repetative signal (no frequencies
below the fundamental) but instead of sampling every .1 cycles, you sample
every 1.1 cycles.  If the signal is truly repetative, you get exactly the
same answer.  Note that the sample and hold still has to work at the full
bandwidth.


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