CMOS VCO and LNA Using Tuned-Input Tuned-Output Circuits

A tuned-input tuned-output (TITO) VCO utilizes two resonant-tanks to achieve a low measured phase noise of 130.5 dBc/Hz @ 1 MHz offset from 2.5 GHz center frequency. Improvement in phase noise is achieved with comparable power consumption and tuning range compared to a cross-coupled VCO topology. A TITO cell similar to that in the VCO is used as a common-source amplifier in a current-reuse configuration cascaded with a -boosted common-gate amplifier to realize a high gain (20 dB), low power (2.7 mW) LNA. A technique to improve the linearity of the current-reuse LNA is also presented.