A 7.92-9.72 GHz Differential Inverse-Class-F VCO Based on Electrical Coupling

This paper presents a differential inverse-class-F voltage-controlled-oscillator (VCO). By inversely coupling two identical inverse-class-F VCO through two coupling capacitors between the gates of the active devices, the proposed VCO can achieve differential output if the size of the coupling capacitors is selected properly, and therefore gets more suppression to the disturbance of the supply voltage. Meanwhile, the proposed VCO inherits the high FoM performance of the inverse-class-F topology and achieves phase noise improvement due to the electrical coupling. Designed and simulated in 28 nm CMOS process, the post-layout simulation shows that the prototype consumes 5.26 mW from a 0.7-V supply. The PN at 1 MHz offset is −121.4 dBc/Hz when oscillating at 7.92 GHz. The figure-of-merit (FoM) is about 192.2 dBc/Hz.