Resonant Inc.
WIDEBAND FILTER USING TRANSVERSELY-EXCITED FILM BULK ACOUSTIC RESONATORS AND INDUCTIVE CANCELLATION

Abstract:

There are disclosed acoustic filter circuits. A filter circuit includes a first capacitor connected between an input and a first node, a first inductor coupled between the first node and ground, a series resonant circuit comprising a first acoustic resonator and a second inductor connected between the first node and a second node, and a shunt resonant circuit comprising a second acoustic resonator and a third inductor connected between the second node and ground. The first inductor and the third inductor are inductively coupled with a negative mutual inductance.