Patent ID: 7408428
Filing Date: 2008-08-05
Classification: H03H

Abstract:
1. A temperature-compensated film bulk acoustic resonator (FBAR) device, comprising: an FBAR stack, comprising: an FBAR characterized by a resonant frequency having a temperature coefficient, the FBAR comprising opposed planar electrodes and a piezoelectric element between the electrodes, the piezoelectric element having a temperature coefficient on which the temperature coefficient of the resonant frequency depends at least in part, and a temperature-compensating element having a temperature coefficient opposite in sign to the temperature coefficient of the piezoelectric element, and the temperature-compensating element comprises one of: a niobium-molybdenum (Nb—Mo): a cobalt—palladium (Co—Pd) alloy: or a niobium-molybdenum (Nb—Mo) alloy.