A 195.6dBc/Hz peak FoM P-N class-B oscillator with transformer-based tail filtering

A complementary p-n class-B oscillator with two magnetically coupled second harmonic tail resonators is presented. For the same oscillation amplitude (constrained by reliability considerations) and the same tank, the p-n oscillator achieves 3–4dB better Figure of Merit (FoM) than an n-only reference one. After frequency division by 2, the p-n oscillator has a measured phase noise that ranges from −150.8 to −151.5 dBc/Hz at 10MHz offset from the carrier when the frequency of oscillation is varied from 3.64 to 4.15GHz. With a power consumption of 6.3mW, a peak FoM of 195.6 dBc/Hz is achieved.