High-frequency filter and multiplexer
AssigneeMurata Manufacturing Co., Ltd.
InventorToshiaki Takata
Life of this patent
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Abstract
A ladder filter includes at least one series arm resonator connected in a path between first and second input/output terminals, at least two parallel arm resonators each connected between a connection node in the path and a ground, and an inductor connected in series to the at least one series arm resonator. The inductor is closer to the first input/output terminal than are the at least one series arm resonator and the at least two parallel arm resonators. Of the at least two parallel arm resonators, a first parallel arm resonator connected closest to the second input/output terminal has the highest anti-resonant frequency.
Claims13
A high-frequency ladder filter, comprising:
- at least one series arm resonator connected in a path between a first input/output terminal and a second input/output terminal;
- at least two parallel arm resonators each connected between a connection node in the path and a ground;
- and
- an inductor connected in series to the at least one series arm resonator, the inductor being closer to the first input/output terminal than the at least one series arm resonator and the at least two parallel arm resonators are to the first input/output terminal;
- wherein
- of the at least two parallel arm resonators, a first parallel arm resonator connected closest to the second input/output terminal has a highest anti-resonant frequency;
- and
- the first input/output terminal and the connection node to which one of the at least two parallel arm resonators is connected, the one being connected closest to the first input/output terminal, are connected, with none of the at least one series arm resonator interposed therebetween.
Dependencies are inferred from the claim text.