CANCELLATION OF PRODUCTS GENERATED BY HARMONICS OF A SQUARE WAVE USED IN SQUARE-WAVE MIXING

摘要

A mixer circuit includes three square wave mixers and a combiner. A first square wave mixer in the circuit multiplies an input signal with a first square wave. A second square wave mixer and a third square wave mixer in the circuit each multiplies the input signal with a second square wave and a third square wave respectively. The second and third square waves have a same frequency as the first square wave, but phases that respectively lead and lag the phase of the first square wave by a first value. The combiner adds the outputs of the mixers. A low-pass filter external to the mixer circuit filters the sum generated by the combiner to generate a filtered output. In an embodiment, the first value equals forty five degrees, and the filtered output is rendered free of products generated by third and fifth harmonics of the first square wave square.