Fundamental 9.9-to-30GHz 207dBc/Hz FoMT Quad-Core Quad-Mode VCO Utilizing One-Coil-For-All Topology in 40nm CMOS

This paper introduces a 9.9–30.0 GHz quad-core quad-mode VCO featuring a symmetric 2D folded 8-shaped inductor with an embedded triple-peak common-mode resonator (TPCR). The design employs a purely inductive switching scheme to maximize the frequency tuning range (FTR) and utilizes the ultra-wideband TPCR to minimize common-mode (CM) return-path phase fluctuation over the entire FTR. Measurement results demonstrate a continuous and uniform FTR of 101% across four modes, with phase noise (PN) of -128.6 to -135.8 dBc/Hz at a 10 MHz offset. The design achieves a peak FoMT of 206.9 dBc/Hz and a peak FoMTA of 218.1 dBc/Hz.