Phase noise of X-band regenerative frequency dividers

This paper evaluates the design and implementation of experimental low noise regenerative divide-by-two (LNRD) dividers having low phase noise at the output frequency of 4.5 GHz. The noise measurements of the 9 GHz to 4.5 GHz LNRD shows close-in flicker-of-phase noise of /spl Lscr/(1 kHz)=-155 dBc/Hz and broadband thermal noise floor of /spl Lscr/(1 MHz) =-170 dBc/Hz. For the design of the regenerative dividers, several MMIC amplifiers have been evaluated and their phase noise performance compared. The dividers have also been used in the generation of low noise 4.5 GHz microwave signals. The LNRD design was easily extended for the design of a 4.5 GHz to 2.25 GHz LNRD which is currently under construction.