| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave filter which adjusts the pass band width in its increasing direction and has the satisfactory cut-off characteristic at a place near the pass band area. SOLUTION: This surface acoustic wave filter F consists of the surface acoustic wave resonators each having a comb-line electrode which are connected to a ladder circuit. That is, the surface acoustic wave resonators 11a, 11b and 11c including resonators in which at least one has different resonance frequency are connected in parallel to the serial arms of the ladder circuit. Meanwhile, the surface acoustic wave resonators 12a, 12b and 12c including resonators in which at least one has different resonance frequency are connected in series to the parallel arms of the ladder circuit.
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