High spectral purity frequency sources using low noise regenerative frequency dividers

Regenerative frequency dividers with input frequency in the range of 100 MHz to 1 GHz were studied. The phase noise of such dividers shows a 1/f spectrum corresponding to 155 dB. These performances are much better than those of GaAs digital frequency dividers. Using these regenerative frequency dividers at the VHF output of a synthesizer, a frequency source of high spectral purity was achieved, working in the range of 5 to 20 MHz. It can be used to test the spectral purity of oscillators in this frequency range