Filter device
AssigneeMurata Manufacturing Co., Ltd.
InventorHiroya Suzuki
Life of this patent
Estimating the term…
Abstract
A filter device includes at least one series arm resonator connected in series in a signal line and including first and second end portions, parallel arm resonators connected between the signal line and ground, and a capacitor. The parallel arm resonators include a first parallel arm resonator connected on a first end portion side of the at least one series arm resonator, and a second parallel arm resonator connected on a second end portion side of the at least one series arm resonator. The first parallel arm resonator includes a third parallel arm resonator and a fourth parallel arm resonator each connected to the first end portion. The third parallel arm resonator is connected directly to the ground and the fourth parallel arm resonator is connected to the ground via the capacitor.
Claims16
A filter device comprising:
- at least one series arm resonator connected in series in a signal line, the at least one series arm resonator including a first end portion and a second end portion;
- a plurality of parallel arm resonators connected between the signal line and ground;
- and
- a capacitor;
- wherein
- the plurality of parallel arm resonators includes:
- a first parallel arm resonator connected on a first end portion side of the at least one series arm resonator;
- and
- a second parallel arm resonator connected on a second end portion side of the at least one series arm resonator;
- the first parallel arm resonator includes:
- a third parallel arm resonator and a fourth parallel arm resonator each connected to the first end portion;
- the third parallel arm resonator is connected directly to the ground;
- the fourth parallel arm resonator is connected to the ground via the capacitor;
- and
- the capacitor has a structure having a resonant frequency lower than resonant frequencies of the third parallel arm resonator and the fourth parallel arm resonator.
A filter device comprising:
- at least one series arm resonator connected in series in a signal line, the at least one series arm resonator including a first end portion and a second end portion;
- a plurality of parallel arm resonators connected between the signal line and ground;
- and
- a capacitor;
- wherein
- the plurality of parallel arm resonators includes:
- a first parallel arm resonator connected on a first end portion side of the at least one series arm resonator;
- and
- a second parallel arm resonator connected on a second end portion side of the at least one series arm resonator;
- the first parallel arm resonator includes:
- a third parallel arm resonator and a fourth parallel arm resonator each connected to the first end portion;
- the third parallel arm resonator is connected directly to the ground;
- the fourth parallel arm resonator is connected to the ground via the capacitor;
- the second parallel arm resonator includes:
- a fifth parallel arm resonator and a sixth parallel arm resonator each connected to the second end portion;
- the fifth parallel arm resonator is connected directly to the ground;
- and
- the sixth parallel arm resonator is connected to the ground via the capacitor.
A filter device comprising:
- at least one series arm resonator connected in series in a signal line, the at least one series arm resonator including a first end portion and a second end portion;
- a plurality of parallel arm resonators connected between the signal line and ground;
- and
- a capacitor;
- wherein
- the plurality of parallel arm resonators includes:
- a first parallel arm resonator connected on a first end portion side of the at least one series arm resonator;
- and
- a second parallel arm resonator connected on a second end portion side of the at least one series arm resonator;
- the first parallel arm resonator includes:
- a third parallel arm resonator and a fourth parallel arm resonator each connected to the first end portion;
- the third parallel arm resonator is connected directly to the ground;
- the fourth parallel arm resonator is connected to the ground via the capacitor;
- and
- a resonant frequency of the third parallel arm resonator and a resonant frequency of the fourth parallel arm resonator are equal.
Dependencies are inferred from the claim text.