Cryogenic Characterization of Low-Loss Thin-film Lithium Niobate on Sapphire Shear Horizontal Surface Acoustic Wave Devices.

This paper reports a cryogenic study on wideband shear horizontal surface acoustic wave (SH-SAW) devices based on an emerging Y-cut LiNbO/SiO/Sapphire (LNOS) platform. To perform a comprehensive study, low-loss acoustic delay lines (ADLs) equipped with unidirectional transducers were designed with a wavelength (λ) of 4 μm (900 MHz) and a wide fractional bandwidth (FBW) of around 7%, featuring various physical delays ranging from 5λ to 200λ as testing structures. By cooling the temperature down to 5 K, the insertion loss (IL) of the longest ADL and the extracted propagation loss (PL) were characterized as 4.

The Effects of a Coated Material Layer on High-Overtone Bulk Acoustic Resonator and its Possible Applications.

This article describes the characterization and analysis of the effects an additional polymer layer has on a high-overtone bulk acoustic wave resonator based on BaSrTiO (BSTO) thin film by studying its spectral information. From both the simulation (numerical model) and experimental results of the resonator with and without coating, significant difference of both cases is evident in the spacing of the parallel resonance frequencies (SPRFs), effective coupling coefficient ( [Formula: see text]), and quality factor distribution of the resonator. The acoustic velocity of the coated material (SU-8) is calculated from the new periodicity introduced in the SPRF distribution.