Patent ID: 8319585
Filing Date: 2012-11-27
Classification: H03H

Abstract:
1. An elastic wave filter device comprising: an elastic wave filter including an input-side resonator coupled to an output-side resonator, the input-side resonator being connected between an input line and at least one first ground line, the output-side resonator being connected between an output line and at least one second ground line; a parallel trap connected between at least one third ground line and the input line or the output line; and a piezoelectric substrate including the elastic wave filter and the parallel trap provided thereon; wherein the elastic wave filter device includes: the parallel trap is defined by a resonator including a pair of comb-shaped electrodes; one of the pair of comb-shaped electrodes is connected to the input line or the output line and the other one of the pair of the comb-shaped electrodes is connected to the at least one third ground line; and the first ground connection electrode is disposed along a first side of the piezoelectric substrate and the second ground connection electrode is disposed along a second side of the piezoelectric substrate opposite to the first side of the piezoelectric substrate.