Complementary BAW oscillator for ultra-low power consumption and low phase noise

Abstract

A complementary cross coupled BAW parallel resonance oscillator offering ultra-low power consumption and a good phase noise performance is presented. The power consumption in this structure is 50 % less than the classical NMOS based structure without any penalty in the phase noise performance. Rather, this structure serves to reduce the noise contribution of the biasing transistors at the output leading to a marginal improvement in thermal noise performance as compared to the NMOS based structure. Furthermore, the flicker noise upconversion of this complementary structure can be minimized by proper design considerations. The power consumption in case of such a complementary structure based oscillator (designed in 180nm CMOS process) employing a 2.497 GHz BAW resonator is around 675 μW for an amplitude of 300 mV with a phase noise of −140 dBc/Hz at 1 MHz offset.