On the Design of MM-Wave Eight-Phase Super-harmonic VCO in $0.18\mu\mathrm{m}$ CMOS Technology

This paper presents an eight-phase LC voltage controlled oscillator (VCO) using a super-harmonic coupling technique. Eight various phases are created in which there is 45 degrees phase difference between continued outputs. Four oscillators are coupled by two nmos transistor used in each stage acting as a mixer to generate proper second harmonic signals. Second harmonic signal is injected to the center tap of the tank inductor in the next stage. The proposed VCO is simulated in silterra $.18\ \mu\mathrm{m}$ BCD process with the area of $.7\times 0.7\ \mathrm{mm}^{2}$ . The VCO can be tuned from 22.2 GHz to 25.1 GHz, a frequency tuning range of 12.3% at 1.8V supply. With each VCO consuming 2.2 mW DC power (8.8 mW total), the phase noise is −107 dBc/Hz at 1 MHz offset when VCO output frequency is 24 GHz. Maximum FOM of the proposed VCO is 190.16 dB. Comparison results show that the proposed VCO is among the best works.