Patent ID: 8169278

Claim:
A surface acoustic wave device, comprising: a piezoelectric substrate; an IDT electrode provided on a top surface of the piezoelectric substrate; a reflector arranged along a surface acoustic wave traveling direction on both sides of a portion of the piezoelectric substrate where the IDT electrode is arranged; and an insulator member arranged on the piezoelectric substrate to provide a closed space defined by the IDT electrode and the reflector, the insulator member including a sidewall surrounding the space and a top wall closing the top of the space; wherein the reflector including a plurality of electrode fingers is weighted such that lengths of the electrode fingers are successively shorter in a direction extending from an electrode finger at a first end portion of the reflector adjacent to the IDT electrode toward a second end portion of the reflector opposite the first end portion, and the sidewall of the insulator member is inclined with respect to the surface acoustic wave traveling direction in the weighted portion of the reflector.