| 摘要 |
A surface acoustic wave resonator includes: an IDT which is disposed on a quartz substrate with Euler angles of (−1°≦̸&phgr;≦̸1°, 117°≦̸&thetas;≦̸142°, 42.79°≦̸|ψ|≦̸49.57°), which is made of Al or alloy including Al as a main component and which excites a surface acoustic wave in an upper mode of a stop band; and an inter-electrode-finger groove which is formed by recessing the quartz substrate between electrode fingers which form the IDT. Here, the following expression is satisfied: 0.01λ≦̸G  (1), where λ represents a wavelength of the surface acoustic wave and G represents a depth of the inter-electrode-finger groove. The depth G of the inter-electrode-finger groove and a line occupancy &eegr; of the IDT satisfy the following expression: - 2.5 × G λ + 0.675 ≦̸&eegr;≦̸ - 2.5 × G λ + 0.775 ( 5 ) and a number of pairs N of the electrode fingers in the IDT is in the range of the following expression: 160≦̸N≦̸220  (19). |
