Patent ID: 7535322

Claim:
A filter comprising: a plurality of acoustic resonators connected in series between an input port and an output port on an integrated circuit chip, each of said resonators having a pair of electrodes; a first shunt resonator on said integrated circuit chip having a first electrode, connected to an electrode of one of said series-connected resonators, and a second electrode; a second shunt resonator on said integrated circuit chip having a first electrode, connected to another electrode of said series-connected resonators, and a second electrode connected to the second electrode of said first shunt resonator; and an inductor on said integrated-circuit chip having one end connected to said second electrodes of said shunt resonators and another end connected to a contact pad of said chip, wherein an area of the first shunt resonator is made larger than that of a first acoustic resonator of said plurality of acoustic resonators connected in series, said first acoustic resonator being connected to the input port, and wherein an area of the second shunt resonator is larger than that of a second acoustic resonator of the plurality of acoustic resonators which is connected to the first acoustic resonator.