A transformer-based inverted complementary cross-coupled VCO with a 193.3dBc/Hz FoM and 13kHz 1/f3 noise corner

This paper presents a transformer-based inverted complementary cross-coupled voltage-controlled oscillator (VCO) topology. Without compromising the start-up condition, it isolates the source nodes for the cross-coupled devices, suppresses the flicker noise up-conversion, and thus results in a superior phase noise performance. A prototype is implemented in a standard 130nm bulk CMOS process with a core area of 0.34mm
²
. At 1.86GHz, the measured FoM is 190.3/192.2/193.3dBc/Hz at 10k/100k/1MHz offsets with a 1/f
³
phase noise corner of only 13kHz. The VCO consumes 1.1mA from a 1.5V supply. High FoM and low 1/f
³
phase noise corners are consistently achieved over 20.8% frequency tuning range (1.68-2.07GHz).