Mounting one acoustic resonator vertically above another

摘要

A first acoustic resonator or FBAR 26 on a substrate 32 has another, second acoustic resonator 16a mounted vertically separated from and above it. The second acoustic resonator is supported on standoffs 27. The standoffs may be fabricated either on the substrate 32 or the first resonator 26 by way of a lithographic process involving a sacrificial layer (see fig 6). Thus the total area required to implement the resonators of an acoustic filter (see fig 3) is reduced.