A W-Band Low-Phase-Noise Class-F₂₃ VCO With Common-Mode Expansion Based on a Coupling-Coexisting Transformer

This letter proposes a novel implementation for W-band Class-F<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">23</sub> voltage-controlled oscillator (VCO). The proposed transformer exhibits magnetic coupling in both differential mode (DM) and common mode (CM), features a high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i>-factor in DM, and simultaneously provides implicit CM expansion. Therefore, low-phase noise and a low-flicker noise corner are achieved in this design. Harmonic control in the proposed transformer is explicitly demonstrated. The proposed VCO is fabricated using 65-nm CMOS technology. The frequency ranges from 76 to 87 GHz, with a tuning range of 12%. The measured phase noise is −102.5 dBc/Hz, with figures of merit of 183 dBc/Hz at 1-MHz offset. The power consumption of the VCO is 46 mW in an area of 0.144 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>.