A novel temperature stable composite substrates for surface acoustic wave applications

Abstract

The temperature coefficient of delay (TCD) of the surface acoustic wave (SAW) on the amorphous TeO2 /36deg to 46deg Y-X LiTaO3 layered substrates have been investigated. Other characteristics important for SAW applications such as wave modes, electromechanical coupling coefficient (K2) have also been calculated. It is found that they simultaneously have a very high K2 around 8%, a pure transverse surface wave mode and a zero TCD. The TCD can reach zero when the thickness of amorphous TeO2 film is much less than that of conventional SiO2 film, which means SAW devices on such substrates can be fabricated easily.