To provide a surface acoustic wave(SAW) device, for which shoulder characteristics are improved, loss is reduced and the degree of block suppression is increased, and a high-performance antenna branching filter using this SAW device.
Concerning this device in stepwise filter structure constituting serial and parallel arms while using a SAW resonator for which an interdigital electrode 5 is formed on a piezoelectric board 4, weighting is performed to this SAW resonator so that the conductance of interdigital electrode 5 of this SAW resonator can become a small value on a desired frequency band. Then, plural interdigital electrodes 5 are directly serially connected on a single piezoelectric board 4 and formed as one SAW resonator. By respectively changing the electrode pitches of these directly serially connected plural interdigital electrodes 5, respective resonance frequencies are made different and suitable band width is secured.
ONUKI HIDEO
WATANABE KAZUSHI
YUHARA AKITSUNA
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