Universal digital frequency synthesizer using single side band techniques

摘要

An improvement in a digital frequency synthesizer comprising a voltage-controlled oscillator (VCO) for producing a signal SVCO having a frequency fVCO, a first signal generator for generating a plurality of signals SAS having a spectrum of frequencies fAS, all exceeding a given minimum frequency fM, a mixer responsive to SVCO and to SAS to produce an output signal having a frequency (fVCO+/-fAS), a divide-by-N divider responsive to (fVCO+/-fAS) to produce a signal SN having a frequency fN, a second signal generator for generating a first reference signal SR1 having a frequency fR1, a phase detector responsive to SN and SR1 to produce a d.c. control signal Ec whose amplitude varies with the phase relation of SN and SR1, and a filter for supplying Ec back to said VCO, the VCO being responsive to Ec to produce an output signal SVCO of frequency fVCO where (fVCO+/-fAS )=NfR1, an improvement for generating signals in the frequency range NfR1+/-fM and comprising a third signal generator for generating a second reference signal SR2 having a frequency fR2 where (NfR2+fM)