Patent ID: 7446454

Claim:
An energy-trapping-type thickness extensional piezoelectric resonator using a thickness extensional vibration mode, comprising: a piezoelectric substrate having a top surface and a bottom surface, the piezoelectric substrate being polarized in a thickness direction connecting the top surface and the bottom surface; first and second resonance electrodes located in a central area of the top surface and the bottom surface of the piezoelectric substrate, respectively, the first and second resonant electrodes positioned so as to oppose each other with the piezoelectric substrate therebetween; a first terminal electrode provided on a first end surface of the piezoelectric substrate; and a first connection electrode on the top surface of the piezoelectric substrate, the first connecting electrode electrically connecting the first resonance electrode to first terminal electrode, wherein the first connecting electrode does not span the entire width of the piezoelectric substrate, wherein the extensional piezoelectric resonator couples a suppression response having a frequency-temperature-change tendency with a main response of the thickness extensional vibration mode so as to suppress changes in frequency of the main response due to temperature, wherein the piezoelectric substrate has a strip-shape extending in a length direction, the first and second resonance electrodes span an entire width of the piezoelectric substrate in the central area and do not extend to either edge of the substrate in the length direction of the top surface and the bottom surface of the piezoelectric substrate, respectively, and the suppression response is a response resulting from the width of the piezoelectric substrate, and wherein at least one resonance frequency of the suppression response resulting from the width is higher than an anti-resonance frequency of the main response.