A 16.5-to-37.9 GHz Quad-Core Quad-Mode VCO With Compact 0.07 mm ² in 65-nm CMOS

A quad-core quad-mode millimeter-wave (mm-wave) voltage-controlled oscillator (VCO) with wide frequency tuning range (FTR) and compact size is presented in this brief. By using mode switches to lock the phases of the quad-core in different states, both the current paths and coupling directions can be switched. Then, four distinct inductance modes are enabled in the proposed highly integrated quad-mode inductor. Fabricated in 65-nm CMOS process, the proposed VCO achieves a continuous FTR of 78.7%, spanning from 16.5 to 37.9 GHz. The measured peak phase noise at 1-MHz offset is -110.4 dBc/Hz. Benefiting from the tightly coupled and centrally symmetric inductor layout, the core occupies a compact area of 0.07 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>.