Patent ID: 6965282

Claim:
Surface acoustic wave device comprising: a piezoelectric substrate; and an interdigital transducer for input and an interdigital transducer for output, which are respectively disposed on a propagation path of a surface acoustic wave on the piezoelectric substrate, and constituted of at least one interdigital transducer or more, wherein, when an aperture length of the electrode fingers of the interdigital transducer for input or the interdigital transducer for output is defined as X, the interdigital transducer for input or the interdigital transducer for output comprises two split interdigital transducers respectively including electrode fingers having an aperture length of approximately X/2, and electrodes of respective electrode fingers in the first and second split interdigital transducers are extracted from the two split interdigital transducers, and disposed in such a way as signals in the two outputs or inputs connected to a balanced terminal pair have a phase difference of 180, and the two split interdigital transducers are connected in series by a common electrode of solid shape, of which electrode width is greater than twice the pitch of the electrode fingers in the two split interdigital transducers, and further the common electrode is connected to the ground potential.