| 摘要 |
PROBLEM TO BE SOLVED: To provide a resonance synthesis type SAW filter in which a group delay time of a pass band is improved. SOLUTION: The resonance synthesis SAW filter is configured by placing two longitudinal connection triple mode SAW filters A, B on a piezoelectric substrate and connecting them in parallel electrically. In this case, let four resonance peak frequencies cased by mis-matching the termination impedance of the filter be F1, F2, F3, F4 in the descending order, then relations of (F3-F4)≈(F1-F2) and 2.0<=F2-F3)/(F1-F2) are in existence.
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