Piezoelectric resonator utilizing bending vibrations and ladder-type filter including the same

摘要

In a piezoelectric resonator utilizing bending vibrations, three or more electrode layers and two or more piezoelectric layers are alternately laminated, at least two layers of the piezoelectric layers are polarized in the thickness direction, first and second end surface electrodes are provided in the end surfaces of the laminated piezoelectric layers, and the electrode layers are connected to each other by using the first and second end surface electrodes such that, in at least one piezoelectric layer, an electric field is generated in the same direction as the polarization direction of the piezoelectric layer, and such that, in at least one of the other piezoelectric layers, an electric field is generated in a direction that is opposite to the polarization direction of the piezoelectric layer.