A 7 GHz FBAR overtone-based oscillator

Film bulk acoustic wave resonators (FBARs) prove to be good candidates for designing low-power oscillators in the low-GHz frequency region. To boost the use of FBAR resonators to higher frequencies, we demonstrate an oscillator that uses an overtone frequency of the FBAR. A 7GHz oscillator is built on a PCB using a commercial pHEMT transistor as an active element and surface mounted passive components. The FBAR is wire bonded to the PCB. The measured phase noise of −110dBc/Hz at 1MHz offset. To the author's knowledge this circuit is the first realized FBAR overtone-based oscillator on PCB.