SURFACE ACOUSTIC WAVE DEVICE, FILTER, COMMUNICATION MODULE AND COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a surface acoustic wave device provided with a plurality of piezoelectric thin film resonators different in resonance frequency in the same filter chip, which can be easily manufactured and has excellent pass-through characteristics while reducing unneeded responses.

SOLUTION: The piezoelectric thin film resonator has a frequency control film 51 provided with a plurality of patterns for adding mass to a membrane part 46. The frequency control film 51 is provided in an area including the membrane part 46 at least. The plurality of patterns in the frequency control film 51 are arrayed in equal cycles, and comprise at least two control film groups 51a and 51b. The interval of the control film groups 51a and 51b is (1/2+N) times [N: natural number] the cycle length of the plurality of patterns.

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