Patent ID: 10069477

Abstract:
A surface acoustic wave device includes: comb-shaped electrodes each including electrode fingers and dummy electrode fingers; and additional films located to cover gaps between tips of the electrode fingers of one of the comb-shaped electrodes and tips of the dummy electrode fingers of the other, wherein each of the additional films overlap with at least one of the electrode fingers and the dummy electrode fingers located lateral to the corresponding gap in a first direction in which the electrode fingers extend or in a second direction intersecting with the first direction, and a distance G of the gap is 0<G≤1.0λ and a film thickness h of the additional films is 0<h/λ≤(0.146G+0.694076)×ρ2/ρ1 where λ is a wavelength of an acoustic wave, ρ1 is a density of a material of the additional films, and ρ2 is a density of aluminum oxide.