Theoretical and Experimental Study on Exclusive-OR Gate Difference-Frequency Mixer
A difference-frequency mixer based on exclusive-or gates with a filter at the output, which processes a variable frequency input signal and a reference input signal (produced by measurement system) to develop an output signal representative of the frequency difference between the two input signals, was studied in theory and simulation experiments. Digital difference-frequency mixers of this kind can be used in the output signal measurement of resonator-based sensors for high resolution and short measure time.
J. F. Dong et al., "Theoretical and Experimental Study on Exclusive-OR Gate Difference-Frequency Mixer", Applied Mechanics and Materials, Vols. 130-134, pp. 1846-1849, 2012