A 24 GHz low power VCO with transformer feedback

A K-band low power VCO fabricated by 0.13 µm CMOS technology is developed. By employing a NMOS cross-coupled pair with a transformer feedback, low phase noise under low dc power condition can be achieved at higher frequency. The VCO exhibits a 2.2 GHz frequency tuning range. The output power and the phase noise at 1 MHz offset are −10 dBm and −113 dBc/Hz, respectively. The dc power consumption is 0.6 V/3 mW. To author's knowledge, this performance achieves the best FOM in CMOS K-band VCOs.