P1H-1 LiNbO3-LiNbO3 High Overtone Bulk Acoustic Resonator 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 30mum. This has been achieved on 3 inches wafers and allows for an accurate selection of the wave characteristics. Harmonic bulk acoustic resonators have been built using this techniques, combining a thinned Y+36 LiNbO
₃
plate and a Y+36 LiNbO
₃
wafer. High quality resonances have been measured on an extended frequency range, allowing for QF products in excess of 8times10
¹³
without any ambiguity.