Single-, Dual- and Octa-Core Millimeter-Wave VCOs with -190 dBc/Hz FOM_T in 22 nm FDSOI CMOS

We present three VCOs with wide continuous FTR and low PN for mm-wave radar, fabricated in 22 nm FDSOI CMOS. All designs employ a common core optimized for FOM_T using a systematic methodology. VCO1 is a single-core push-push VCO achieving a 16.7% FTR at 121.8 GHz, with −109.2 dBc/Hz PN at 10 MHz offset and 3 mW power consumption. VCO2 is a dual-core push-push VCO employing a tail transformer that enables tail filtering, multi-core coupling, and non-invasive second-harmonic extraction. As a result, VCO2 achieves a 3 dB improvement of mean PN compared to VCO1. To overcome layout constraints limiting further multi-core scaling, VCO3 combines coupling techniques to realize an octa-core architecture. It achieves a 15.1% FTR at 52.7 GHz and −125.7 dBc/Hz PN. All three VCOs exhibit a FOM_T of -190 dBc/Hz. To our knowledge, this represents the best reported FOM_T for silicon VCOs with continuous FTR at comparable frequencies.