A Regenerative Frequency Comb

Abstract

The paper describes a regenerative frequency comb generator (RCG) used to synthesize a signal coherent with the input signal with a fractional multiplication of m/n, where the frequency of n is proportional to 1/tau, where tau is the loop delay, and m is a positive integer less than n. The RCG was described and its performance was compared with traditional regenerative dividers, digital dividers and multipliers. Preliminary data for a divide by ten whose residual noise was measured at 100 MHz suggest superior performance to low noise digital dividers, with a SSB noise of -145 dBc/Hz at 100 Hz and 1/f characteristic. While the broadband performance of the regenerative dividers and conjugate regenerative dividers studied in the past have not attained, a -162 dBc/Hz at 100 kHz offset have been attained and expect to be able to improve the overall noise further by applying techniques investigated in the aforementioned devices