Almost all-digital sinewave-product generation for frequency synthesis applications

We propose a frequency mixer built from almost exclusively digital components. The circuit produces a sinusoidal signal at frequency omega₁ plusmn omega₂ when its input frequencies are Nomega₁ and Nomega₂, both provided in the form of digital clocks. As it uses almost exclusively digital circuitry, it can easily be integrated with digital CMOS and possesses many advantages inherent in digital circuits. Predictions of the system´s performance have been supported with spectral measurements of a discrete implementation.