Patent ID: 8049581

Claim:
A piezoelectric filter comprising: first and second piezoelectric vibrators, each having: a substrate; a lower load film formed on the substrate; a lower electrode formed on the lower load film; a piezoelectric element formed on the lower electrode; an upper electrode formed on the piezoelectric element; and an upper load film formed on the upper electrode, wherein the piezoelectric filter is formed by electrically connecting the first and second piezoelectric vibrators, and wherein the piezoelectric element of the first piezoelectric vibrator and the piezoelectric element of the second piezoelectric vibrator correspond to respectively different areas of the same piezoelectric element, and wherein resonance frequencies of the first and second piezoelectric vibrators are adjusted by the respective lower load film and upper load film of the first piezoelectric vibrator and the second piezoelectric vibrator so that the resonance frequencies of the first and second piezoelectric vibrators are made different from each other.