FBAR OVERTONE–BASED OSCILLATORS USING 90 nm CMOS
M. ELBARKOUKY, P. WAMBACQ, Y. ROLAIN

Abstract. Film bulk acoustic wave resonators (FBARs) are useful to make very selective filters and low–power oscillators in the low–GHz frequency region. To extend the useful range of FBARs to higher frequencies, we demonstrate the use of an FBAR at an overtone frequency. A Colpitts oscillator has been designed by combining via wire bonding 90 nm CMOS circuitry with an FBAR on a separate chip. The simulated oscillation frequency of the oscillator is 6.5 GHz with power consumptions of 812 µW in the core. The oscillator achieves phase noise –110 dBc/Hz at 1 MHz offset form the carrier. To the authors’ knowledge this is the first FBAR overtone based oscillator in the low GHz range.