A design of low power 70GHz CMOS VCO for wireless communication system

A 70GHz Voltage Controlled Oscillatior (VCO) for wireless communication system is proposed by 0.11μm CMOS process. The VCO is designed by a center-tapped spiral inductor and NMOS cross-coupled structure and includes output buffer. The designed VCO oscillates from 69.95 to 71.62GHz and this frequency band is proper to wireless communication system in cars. The measured output power is -22.9dBm and phase noise is -78.67dBc/Hz at 1MHz offset at 71.18GHz. The power consumption of the VCO core is only 2.6mW at the supply voltage of 1.2V. VCO shows good figure of merit (FOM) of -171.57dBc/Hz.