Binary frequency synthesizer

摘要

A voltage controlled oscillator has coupled thereto N capacitors in different permutation under control of an N stage binary counter and a counter drive signal enabling the generation of signals having 2N discrete frequencies. A phase locked loop is employed to stabilize each of the 2N frequencies. This loop includes a mixer coupled to a harmonic generator and the output of the oscillator. The mixer output is applied to a crystal filter whose output is phase compared with a reference signal and the resultant output is employed to stabilize the oscillator.