| 摘要 |
It is possible to provide an elastic boundary wave device capable of suppressing increase of conductor resistance and obtain a small delay time temperature coefficient eve when a frequency is increased. An elastic boundary wave device (10) includes an IDT (13) arranged between a first medium (11) and a second medium (12). The IDT (13) is divided into two portions in the thickness direction. The plane between the two portions serves as a boundary plane. A sound velocity of an elastic boundary wave when the IDT (13) is configured by setting energy of an elastic boundary wave of the first medium (11) side from the boundary to E1 and energy of an elastic boundary wave of the second medium (12) side from the boundary to E2 is made identical to a sound velocity of an elastic boundary wave when the IDT (13) is configured by using only a conductor having the maximum density constituting the IDT (13) as follows. Under the condition that the IDT (13) is configured by only a conductor layer having the maximum density, the elastic boundary wave energy satisfies E1/E2 < E1'/E2' wherein E1' is energy of an elastic boundary wave of the first medium (11) side from the boundary and E2' is energy of the second medium (12) side from the boundary. ® KIPO & WIPO 2007
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