Phase noise performance of microwave analog frequency dividers applicationto the characterization of oscillators up to the millimeter-wave range

The phase noise performance of two different microwave analog frequency div iders is characterized and compared with the values obtained using simple t heories of noise in injection-locked systems. The direct measurement of the divider noise with a low phase noise synthesizer is not accurate enough, a nd the residual noise technique is used. The noise levels observed using th is technique, between -120 and -155 dBc/Hz at a 10 kHz offset frequency, de monstrate that this divider noise is much lower than the phase noise of mos t microwave free running oscillators, even if this noise is still high with respect to the residual noise of amplifiers realized with the same active devices. The down conversion of microwave sources up to 40 GHz is proposed as an application example.