Patent ID: 7830226

Claim:
A film bulk acoustic resonator (FBAR) filter, comprising: at least one series resonator positioned between an input port for inputting a frequency signal and an output port for outputting a frequency signal; at least two shunt resonators respectively positioned between the input and output ports and a ground; a first trimming inductor for connecting the at least two shunt resonators and the ground; and a second trimming inductor positioned between the at least two shunt resonators, one end of which is connected to a node between one shunt resonator and ground, and the other end of which is only connected to the other shunt resonator directly; wherein a plurality of sub-filters, comprising the at least one series resonator, the at least two shunt resonators, and the first and second trimming inductors, are connected to each other such that each of the sub-filters are connected in series, and at least one attenuation resonator is positioned in series between each of the plurality of sub-filters.