BAW Piezoelectric Resonators

Abstract

This chapter describes basic properties and modeling of resonators using acoustic waves propagating in a solid body. This type of waves is called the bulk acoustic wave (BAW), which can be excited and detected efficiently using piezoelectricity. The resonators are widely used in various applications such as clock generation, frequency filtering, and sensing. The most popular ones are crystal quartz resonators [1] for relatively low frequency applications (<100 MHz). Recently BAW resonators fabricated by thin film and micromachining technologies, i.e., film bulk acoustic resonators (FBARs) [2], are getting popular for relatively high frequency applications (>1–3 GHz) such as duplexers used in mobile and smart phones.