Patent ID: 9106206
Filing Date: 2015-08-11
Classification: H03H

Abstract:
1. A surface acoustic wave filter, comprising: an input terminal coupled to receive an input signal; a first output terminal configured to output a first output signal; a second output terminal configured to output a second output signal; a reference terminal configured to apply a reference potential; an arrangement of transducers configured to convert electrical/acoustic signals into acoustic/electrical signals, the arrangement of transducers comprising at least one first transducer coupled to the input terminal and the reference terminal, at least one second transducer coupled to the first output terminal and the reference terminal, and at least one third transducer coupled to the second output terminal and the reference terminal, respectively; and a capacitor coupled to the first output terminal and/or the second output terminal and/or the reference terminal in a way that either the capacitor is coupled between the first and second output terminals or the capacitor is coupled between one of the first and second output terminals and the reference terminal; wherein the at least one first, second and third transducers each have a first comb-shaped structure and a second comb-shaped structure; wherein the first and second comb-shaped structures of each of the at least one first, second and third transducer are arranged on a carrier substrate; wherein the capacitor is embodied as a comb-shaped structure on the carrier substrate; wherein the comb-shaped structure of the capacitor is arranged on the carrier substrate in a different direction than that of the first and second comb-shaped structures of the at least one first, second and third transducers; and wherein the comb-shaped structure of the capacitor is arranged on the carrier substrate in such a way that no acoustic wave is excited when a voltage is applied to the comb-shaped structure of the capacitor.