An 8 to 9 GHz LC-VCO and harmonic-suppressed CML divider with low supply voltage for FMCW synthesizer

An 8 GHz to 9 GHz voltage controlled oscillator (VCO) and harmonic-suppressed current mode logic (CML) divider with low supply voltage is proposed, analyzed, and implemented using 130-nm CMOS process. Compared with the conventional LC-VCO and CML divider, the proposed VCO presents an adjustable tuning range, while the divider presents a better harmonic suppression at low supply voltage. The simulated frequency tuning range of the VCO is from 7.91 GHz to 9.24 GHz when A1A0 is 11 and from 8.12 GHz to 8.75 GHz when A1A0 is 10. The simulation shows that the VCO achieves the phase noise of -106.2dBc/Hz at 1 MHz offset. The VCO and the CML divider consume 4 mW and1.36 mW respectively with 0.8 V supply.