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1. (WO2018043608) ACOUSTIC WAVE FILTER DEVICE, HIGH-FREQUENCY FRONT-END CIRCUIT, AND COMMUNICATION APPARATUS

Pub. No.:    WO/2018/043608    International Application No.:    PCT/JP2017/031269
Publication Date: Fri Mar 09 00:59:59 CET 2018 International Filing Date: Thu Aug 31 01:59:59 CEST 2017
IPC: H03H 9/64
H03H 9/145
Applicants: MURATA MANUFACTURING CO., LTD.
株式会社村田製作所
Inventors: NOSAKA, Koji
野阪 浩司
Title: ACOUSTIC WAVE FILTER DEVICE, HIGH-FREQUENCY FRONT-END CIRCUIT, AND COMMUNICATION APPARATUS
Abstract:
A filter (10) has a serial arm resonator (s1) connected to a path connecting an input-output terminal (11m) and an input-output terminal (11n), and has parallel arm resonators (p1, p2) that are connected between the same node (x1) on said path and ground, wherein: the parallel arm resonator (p2) has a resonant frequency higher than that of the parallel arm resonator (p1); the parallel arm resonator (p2) has an anti-resonance frequency higher than that of the parallel arm resonator (p1); and the parallel arm resonator (p2) has an IDT electrode (131) for exciting acoustic waves, but has no reflector.