50 GHz LC-active oscillator in 65 nm CMOS

A 50 GHz cross-coupled oscillator employing a millimeter-wave active inductor in the LC tank has been designed and realized in 65 nm bulk CMOS technology. The measurement results show an equivalent inductance of 133 pH with a quality factor exceeding 400 at 50 GHz, demonstrating experimentally the implementation of high-Q active inductors operating at the millimeter-waves in CMOS technology. The measurement results show a phase noise of -85 dBc/Hz at 1 MHz from the carrier when the active inductor is switched off and -91 dBc/Hz when it is switched on, corresponding to 6 dB phase noise improvement.