Patent ID: 7057476

Claim:
A noise suppression method for a wave filter, the wave filter being provided with at least one film bulk acoustic resonator (FBAR), a piezoelectric film being located at the center of the FBAR, the piezoelectric film having an upper surface and a lower surface, said upper and lower surfaces being plated with conductive material to be used as an upper working electrode and a lower working electrode, respectively, wherein a region overlapping the piezoelectric film and the upper and lower working electrodes forms an acoustic resonant cavity, the noise suppression method comprising at least the following steps of: selecting the region overlapping the piezoelectric film and the upper and lower working electrodes in the structure of the FBAR; and providing a plurality of noise scatterers in the structure embodied by the region, wherein said noise scatterers are filled with material that increases a material characteristic difference and a cross section of the scatters is of a random geometrical shape.