Low‐power three‐path inductor class‐C VCO without any dynamic bias circuit

A 2.48 GHz class‐C voltage controlled oscillator (VCO) without any dynamic back bias circuit is presented. The VCO uses three‐path high Q ‐factor inductor as the low loss resonator and class‐C cross‐coupled nMOSFET pairs for high dc/RF conversion efficiency and direct cross‐coupled pMOSFET for dc current reuse. At the supply voltage of 1.2 V, the core power consumption is 0.24 mW. The phase noise of the VCO is −124 dBc/Hz and the VCO figure of merit is −197.0 dBc/Hz. The VCO was implemented in the TSMC standard 0.18 μm SiGe BiCMOS process and occupies a die area of 0.799 × 0.809 mm 2 .