Patent ID: 7528685
Filing Date: 2009-05-05
Classification: H03H

Abstract:
1. A lamb wave type high frequency device, comprising: an interdigital transducer (IDT) electrode having an electrode finger interdigitated therein; a pair of reflectors having an electrode finger and being disposed at both sides of a propagation direction of a lamb wave excited by the IDT electrode; and a piezoelectric substrate on a surface of which the IDT electrode and the reflectors are disposed, an insulation film deposited so as to cover the IDT electrode, wherein a pitch of the electrode finger of the IDT electrode and a pitch of the electrode finger of the reflectors are different from one another and Δt/λ satisfies a relation of Δt/λ≦0.044, where Δt is a height difference between a first surface of the insulation film disposed on the IDT and a second surface of the insulation film disposed on the piezoelectric substrate, and λ is a wavelength of a lamb wave.