Frequency sources and filters applications using high overtone bulk acoustic resonators exhibiting high Q.f product

Bulk acoustic waves excited in thin piezoelectric films have revealed their capabilities for addressing the problem of high frequency RF filters and frequency sources (above 1 GHz). In this paper, we propose an alternative to thin film deposition consisting in single crystal wafers bonded on substrate (high quality) and thinned down, allowing for plate thickness close to 30 mum. This has been achieved on 3 inches wafers and allows for an accurate selection of the wave characteristics.