Patent ID: 6229246
Filing Date: 2001-05-08
Classification: H03H

Abstract:
A piezoelectric resonator comprising:a piezoelectric body;a first excitation electrode disposed on a first outer surface of said piezoelectric body, said first excitation electrode having a width that is substantially equal to the width of said piezoelectric body;a second excitation electrode disposed on a second outer surface of said piezoelectric body, said second excitation electrode having a width that is substantially equal to the width of said piezoelectric body, wherein said second excitation electrode opposes said first excitation electrode with said piezoelectric body therebetween;at least one internal electrode disposed inside of the piezoelectric body such that the at least one internal electrode at least partially opposes both the first excitation electrode and the second excitation electrode;a resonating portion defined by an area of overlap between the first excitation electrode, the second excitation electrode, and the internal electrode; anda plurality of vibration-attenuating portions disposed at opposing sides of the resonating portion and vibrating in N order harmonics of a thickness extensional vibration mode;wherein the equation of .vertline.Dr-Di.vertline.=Di/10 is satisfied, wherein Dr represents the distance between the first excitation electrode and the internal electrode and the value Di is substantially equal to T/N, wherein T is the thickness of the piezoelectric body and N is the order of harmonic vibrations of the thickness-extensional vibration mode.