Methods, systems, and apparatuses, and combinations and sub-combinations
thereof, for down-converting an electromagnetic (EM) signal are described
herein. Briefly stated, in embodiments the invention operates by
receiving an EM signal and recursively operating on approximate half
cycles (1/2, 11/2, 21/2, etc.) of the carrier signal. The recursive
operations can be performed at a sub-harmonic rate of the carrier signal.
The invention accumulates the results of the recursive operations and
uses the accumulated results to form a down-converted signal. In an
embodiment, the EM signal is down-converted to an intermediate frequency
(IF) signal. In another embodiment, the EM signal is down-converted to a
baseband information signal. In another embodiment, the EM signal is a
frequency modulated (FM) signal, which is down-converted to a non-FM
signal, such as a phase modulated (PM) signal or an amplitude modulated
(AM) signal.