Elastic wave branching filter

Abstract

An elastic wave surface acoustic wave duplexer includes an antenna terminal, a transmission filter, a reception filter, and a plurality of elastic wave resonators connected in series between the antenna terminal and the reception filter. The reception filter is a longitudinally coupled resonator-type surface acoustic wave filter including a plurality of IDT electrodes and arranged along a propagation direction of elastic wave. A combined capacitance of the plurality of surface acoustic wave resonators is smaller than a capacitance of the IDT electrodes and included in the plurality of IDT electrodes and connected to the antenna terminal.

Dependencies are inferred from the claim text.