I'm using an ADAU144X at 192kHz in an application to double a 25kHz sinewave sync signal to obtain a 50kHz operating frequency. Multiplying the signal by itself and DC-blocking the output does the job just fine, but intuitively I have this feeling that multiplying something by itself should just increase amplitude exponentially as the waveform rises from the zero crossing. I am having trouble visualizing this process in four quadrants however. I get about a 12dB loss through the multiplier, and although everything works I would dearly love to understand circuit action in non-mathematical terms. Can someone explain this simply or point me to a source? Thanks!