BAW resonator with temperature compensating part

摘要

We propose a BAW resonator (RES) with a temperature compensation part. This resonator is constructed on a substrate (SU) and an acoustic mirror (AS). A compensation layer (KS) is provided between the acoustic mirror and the lowermost electrode layer (E1), the material of which has a positive temperature coefficient of viscoelastic properties. The reduction in piezoelectric coupling by this compensation layer is minimized using the total layer thickness of the compensating layer and the top low impedance layer (LI) of the acoustic mirror, which is an odd multiple of / 4, Is at least 3 / 4, and is the wavelength of the sound wave.