Acoustic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorMinefumi Ouchi
Life of this patent
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Abstract
An acoustic wave device includes a piezoelectric film made of lithium niobate or lithium tantalate, first and second busbar electrodes located on the piezoelectric film and opposite to each other, and first and second electrode fingers and each including one end coupled to the first busbar electrode or the second busbar electrode. The acoustic wave device uses bulk waves in a first thickness-shear mode. A first gap is provided between the first busbar electrode and the second electrode finger. A second gap is provided between the second busbar electrode and the first electrode finger. A length of the first gap and the second gap in a direction in which the first and second electrode fingers extend is about 0.92p or longer, where p is a center-to-center distance between the adjacent first and second electrode fingers.
Claims20
An acoustic wave device comprising:
- a piezoelectric film made of lithium niobate or lithium tantalate;
- a first busbar electrode and a second busbar electrode located on the piezoelectric film and opposite to each other;
- and
- a first electrode finger and a second electrode finger on the piezoelectric film, the first electrode finger including one end coupled to the first busbar electrode, the second electrode finger including one end coupled to the second busbar electrode;
- the acoustic wave device being configured to use a bulk wave in a first thickness-shear mode;
- wherein
- the first electrode finger and the second electrode finger extend in a first direction, the first direction is perpendicular to a second direction, the first electrode finger and the second electrode finger face each other in the second direction;
- a first gap is provided between the first busbar electrode and the second electrode finger, and a second gap is provided between the second busbar electrode and the first electrode finger;
- and
- a length of the first gap in the first direction and a length of the second gap in the first direction are both about 0.92p or longer, where p is a center-to-center distance between the first electrode finger and the second electrode finger, and the first electrode finger and the second electrode finger are adjacent to each other.
An acoustic wave device comprising:
- a piezoelectric film made of lithium niobate or lithium tantalate;
- a first busbar electrode and a second busbar electrode located on the piezoelectric film and opposite to each other;
- and
- a first electrode finger and a second electrode finger on the piezoelectric film, the first electrode finger including one end coupled to the first busbar electrode, the second electrode finger including one end coupled to the second busbar electrode;
- wherein
- d/p is about 0.5 or smaller, where d is a thickness of the piezoelectric film, p is a center-to-center distance between the first electrode finger and the second electrode finger, and the first electrode finger and the second electrode finger are adjacent to each other;
- the first electrode finger and the second electrode finger extend in a first direction, the first direction is perpendicular to a second direction, the first electrode finger and the second electrode finger face each other in the second direction;
- a first gap is provided between the first busbar electrode and the second electrode finger, and a second gap is provided between the second busbar electrode and the first electrode finger;
- and
- a length of the first gap in the first direction and a length of the second gap in the first direction are both about 0.92p or longer.
Dependencies are inferred from the claim text.