SURFACE ACOUSTIC WAVE FILTER, ANTENNA DUPLEXER, HIGH FREQUENCY MODULE USING THE SAME, AND COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To solve the problems that a conventional surface acoustic wave filter is large in size, and when wiring electrodes are crossed in a grade separated manner, capacitive coupling is caused by the wiring electrodes with each other and in-band characteristics are degraded.

SOLUTION: A surface acoustic wave filter 100 comprises a first longitudinal mode type filter 107 and a second longitudinal mode type filter 113 formed on a piezoelectric substrate 101. On wiring electrodes 120 and 121, insulating layers 122 and 123 are formed, and other electrode fingers of IDT electrodes 103 and 109 are connected by a wiring electrode 124 and further connected to electrode pads 126 and 127 connected to a ground terminal GND by a wiring electrode 125 which is formed above the wiring electrode 124 and electrically connected thereto. In the electrode width of the wiring electrode 125, the electrode width in a portion where the wiring electrode 121 and the wiring electrode 125 are crossed each other in a grade separated manner via the insulating layer 123 is configured smaller than the electrode width of the other portion.

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