A 13.4-31.8-GHz Single-core Dual-mode VCO with Mode-independent Transformer-switching Technique in 55nm CMOS

In this paper, a single-core dual-mode millimeter-wave (mm-wave) voltage-controlled oscillator (VCO) using a compact dual-mode LC network with a mode-independent switched transformer technique is proposed with SMIC 55-nm CMOS design kit. Each core contains a 4-bit switched capacitor array and a switchable transformer to maximize the entire tuning range. In simulation results, the proposed oscillator exhibits a 81.4% tunning range from 13.4 to 31.8 GHz. The best phase noise at 1-MHz offset is -115.4 dBc/Hz, corresponding to the frequency of 13.4 GHz. The VCO consumes 8.38-to-14.88 mW from a 0.6 V supply voltage, achieving 192.32 dBc/Hz FOM and 212.32 dBc/Hz FOMT, respectively. The core area is 0.066 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>.