Patent ID: 6198200
Filing Date: 2001-03-06
Classification: H03H

Abstract:
A piezoelectric resonator, comprising:a piezoelectric body including a plurality of piezoelectric layers and a plurality of side edges;first and second excitation electrodes disposed on both sides of the piezoelectric body and being opposed to each other with the piezoelectric body disposed therebetween;at least one layer defining an internal electrode inside of the piezoelectric body and arranged to at least partially oppose the first and second excitation electrodes with the piezoelectric layers disposed therebetween;a resonance portion;a pair of vibration-attenuating portions disposed on opposite sides of the resonance portion; whereinsaid resonance portion is defined by a portion of the piezoelectric body where the first and second excitation electrodes and the internal electrode are overlapped in a thickness direction thereof, said first and second excitation electrodes being arranged to extend to or near to the side edges of the piezoelectric body in a direction that is substantially perpendicular to a first direction which is a direction passing through both of the pair of vibration-attenuating portions located on both sides of the resonance portion; andsaid piezoelectric body having a ratio L/D within a range of about 9.0 to about 14.0 in which L represents the length in the first direction of the piezoelectric body, T represents the thickness of the piezoelectric body, and D=T/N, where N represents an order of higher harmonics in a thickness extensional vibration mode.