Low-Power Dual-Core Inductively Coupled 40 GHz Push-Push VCO in 22nm FDSOI CMOS

We present a 39.6-to-41.8 GHz push-push dual-core cross-coupled voltage-controlled oscillator (VCO) in a 22 nm FDSOI CMOS technology. The two cores are coupled inductively. The passive core coupling device serves multiple purposes: a) as H2 filter to enhance phase noise; b) to provide bias; and c) to extract the second harmonic in a non-invasive way and forward it to the output buffer. The VCO achieves in measurement a low phase noise of −102 dBc/Hz at 1 MHz offset at 39.65 GHz and an output power of − 10 dBm. The VCO including buffers dissipates 24.5 mW from a single 0.75 V supply, while both cores consume only 19.7 mW. Fundamental rejection of better 37 dB is achieved over the entire frequency tuning range (FTR). The chip occupies only 0.3 mm² including pads. The circuit achieves a very good FoM of −181 dBc/Hz at 1 MHz offset.