Miniaturized mmWave Tri-Band VCO Using Self- and Mutual-Mode-Controlled Inductor

This article presents a miniaturized tri-band complementary metal-oxide-semiconductor (CMOS) voltage-controlled oscillator (VCO) utilizing the self- and mutual-mode-controlled inductor (SMCI) without increasing chip area. Additionally, the degradation in phase noise due to the ON-resistance of the switch used for reconfigurable operation is eliminated with a configuration of paired switches and multiple oscillation cores. The proposed SMCI includes outer and inner windings with a center winding connected to the middle of the other two windings; it operates in three modes resulting in different inductances by reconfiguring the connectivity of the four ports. Graphical optimization based on the equivalent circuit with a mutual analysis of segment modeled SMCI is used to present a design strategy in which the inductance of each mode can be independently adjusted in terms of the target frequency ratio. The VCO implemented in a 28-nm CMOS process exhibits a frequency ranging from 16.79-20, 21.87-25.8, and 32.01-38.3 GHz for each band with the corresponding phase noise and tuning range figure-of-merit (FoM {T}) values of -189, -188.3, and -187.8 dBc/Hz. The fabricated chip consumes average power of 12.73 mW and occupies an area of 0.043 mm2.