LOW-LOSS SURFACE ACOUSTIC WAVE DEVICE COMPRISING DIELECTRIC LAYER WITH HIGH PERMITTIVITY

摘要

The invention concerns a low-loss surface acoustic wave device (or SAW device) and is more particularly applicable to SAW devices operating in frequency bands higher than one gigahertz. The inventive device comprises a piezoelectric substrate (2) formed from lithium tantalate (LiTaO3) or lithium niobate (LiNbO3) crystal with Y-X cross-section, an assembly of conductive electrodes (3) and a thin layer (4) of dielectric material with hardness and dielectric permittivity higher than that of the substrate, deposited substantially uniformly on the surface of said substrate, the electrodes being arranged on said layer. Advantageously, the dielectric material (4) consists of titanium dioxide (TiO2).