A novel low noise regenerative divide-by-four circuit

Discusses a novel design of a self starting regenerative divider that permits division by 3, 4, 5, 6... instead of the usual 2. This is accomplished by having the loop oscillate simultaneously at two different frequencies, e.g., at f/4 and 3f/4. A prototype of the divide-by-four circuit has been constructed for an input frequency of 400 MHz. This divider exhibits very low phase noise L(1 kHz) = -161dBc/Hz and L(100 kHz) = -169 dBc/Hz,, which is at least 8 dB lower than its constituent parts. Simple modifications of the feedback loop of the prototype enable it to divide by 3, 5 and 8. Operation at divide by 10 appears feasible.