A low power low phase noise dual-band multiphase VCO
This paper presents a low-power low-phase noise multiphase VCO that operates in 2.5GHz and 5.0GHz frequency bands. The dual-band multiphase VCO uses the frequency doubling method to generate the higher band signals from the lower band signals, and it shows excellent phase noise performance compared to other dual-band multiphase VCOs presented in literature. The VCO has been implemented in 0.18?m CMOS technology, and its frequency is tunable from 2.23GHz to 2.68GHz and from 4.46GHz to 5.36GHz. The measured phase difference between the I/Q signals is 90.0/88.9 for the two frequency bands respectively. The phase noise figure-of-merits (FOMs) for the two frequency bands are ?189.4dB and ?185.1dB.
low power low phase noise vco dualband quadrature