Surface acoustic wave apparatus and communications unit

摘要

In a surface acoustic wave (SAW) apparatus, a first SAW filter device (1) and a second SAW filter device (3) are disposed on a piezoelectric substrate (10) so that the propagation paths are overlapped. When the center-to-center distance between the first and second SAW filter devices (1, 3) are indicated by d 1 , and when the thickness of the piezoelectric substrate (10) is indicated by t, the first and second SAW filter devices (1, 3) and the piezoelectric substrate (10) are disposed so as to satisfy the condition d 1 ‰¤ 2.3 × t or d 1 ‰¥ 2.8 × t.