Film bulk acoustic resonator filter

摘要

A ladder-type film bulk acoustic resonator (FBAR) filter comprises two series FBARs and two parallel FBARs. Each FBAR has a top electrode, a bottom electrode, and a piezoelectric layer sandwiched between the top and bottom electrodes. The top electrodes of the two series FBARs form part of a signal line of a coplanar waveguide transmission line. The top electrodes of the two series FBARs are connected to associated circuitry. The two series FBARs have a common bottom electrode.