Work

High coupling and highly stable leaky surface acoustic waves on LiTaO 3 thin plate bonded to quartz substrate

Year: 2018

Type: article

Abstract: The propagation properties and resonance characteristics of leaky surface acoustic waves (LSAWs) and longitudinal-type LSAWs (LLSAWs) on a LiTaO 3 (LT) thin plate bonded to an AT-cut quartz substrate were investigated experimentally. For the LSAWs and LLSAWs, the bonded structures of 36° Y -cut X -propagating LT (36°YX-LT)/AT-cut 90° X -propagating quartz (AT90°X-quartz) and X -cut 31° Y -propagating LT (X31°Y-LT)/AT-cut 45° X -propagating quartz (AT45°X-quartz) were fabricated, respectively. For the LSAW on 36°YX-LT/AT90°X-quartz, the electromechanical coupling factor ( K 2 ) of 11.1% was obtained at an LT thin-plate thickness of 0.25 wavelength, whereas K 2 for a single LT substrate was measured to be 5.7%. For the LLSAW on X31°Y-LT/AT45°X-quartz, K 2 increased from 2.8% for the single LT substrate to 7.2% at an LT thin-plate thickness of 0.14 wavelength. Furthermore, K 2 of approximately 12% and the temperature coefficient of frequency (TCF) of 0 ppm/°C were theoretically obtained simultaneously for the LSAW on 36°YX-LT/AT-cut 90°X-quartz at a certain thin-plate thickness.

Source: Japanese Journal of Applied Physics

DOI: 10.7567/jjap.57.07ld21