Patent ID: 7386286

Claim:
A method for providing frequency discrimination/comparison and phase detection/comparison using complex single side-band (SSB) down conversion, the method comprising: receiving a local oscillator (LO) of frequency ω o and phase θ(t), in-phase and quadrature signals; receiving a carrier signal of carrier frequency ω c and phase φ(t), in-phase and quadrature signals; multiplying each of said in-phase and quadrature LO signals with each of said in-phase and quadrature carrier signals, thereby generating four converted signals; combining in two pairs said four converted signals, to produce the in-phase LSB signal and the quadrature LSB signal; delaying one of said LSB signals by a time delay τ to produce a delayed LSB signal; multiplying said delayed LSB signal with said other LSB signal, to produce the baseband signal BB(t); and outputting said baseband signal BB(t), wherein said signal BB(t) has a DC voltage component substantially proportional to a frequency difference ω c −ω o , and when this frequency difference is substantially near or equal to zero then said output signal BB(t) assumes a DC voltage substantially proportional to a phase difference φ(t)−θ(t).