Birch, Stewart, Kolasch & Birch
Acoustic surface wave device
 An acoustic surface wave device comprises a transducer including an interdigital electrode formed on the surface of a piezoelectric material substrate and cooperative with the same for converting an electrical signal into an acoustic surface wave and vice versa. The interdigital electrode comprises at least two divided comb shaped electrodes divided in the propagating direction of the acoustic surface wave and a common comb shaped electrode commonly coupled in an interdigital manner to the two divided comb shaped electrodes. Thus, the above described two comb shaped electrodes are disposed such that both divided electrodes arranged in succession in the propagating direction of the acoustic surface wave while the fingers of both divided electrodes extend in the same direction and the common comb shaped electrode is disposed such that the fingers of the common comb shaped electrode are interdigitated with the fingers of both divided comb shaped electrodes. The electrode finger of each of both comb shaped electrodes at the end adjacent to the opposite divided comb shaped electrode comes close to each other at a dividing region without interposition of any finger of the common comb shaped electrode. Both divided comb shaped electrodes are connected to different potentials, respectively. The length of the electrode finger of each of the divided comb shaped electrodes adjacent to each other at the dividing region is selected to be shorter than the overlapping lengths of the adjacent electrode fingers that are overlapped with each other, whereby discontinuity of the surface wave energy in the dividing region is eliminated or mitigated. 
Murata Manufacturing Co., Ltd.
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inventional inventional inventional inventional
Hiromichi Kenji Atsushi
Yamada Suzuki Inoue