Piezoelectric resonator
AssigneeMurata Manufacturing Co., Ltd.
InventorAkihiko Shibata
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Abstract
A piezoelectric resonator using a thickness extensional vibration mode, comprises a vibrator portion made up of two or more layers of piezoelectric thin-films where the piezoelectric thin-films and a plurality of insulating thin films are alternately laminated. An alternating voltage is independently applied to each layer of the piezoelectric thin-films for a higher-order vibration mode to be dominantly excited.
Claims35
A piezoelectric resonator using a thickness extensional vibration mode, the piezoelectric resonator comprising a vibrator portion made up of n layers of piezoelectric thin-film, n being an integer greater than or equal to 2, each of the piezoelectric thin-film layers being separated by a respective insulating thin-film layer, the distance dn to the center of each of the n piezoelectric thin-film layers from a first side of the vibrator portion, being determined by the formula
- dn=t(2m−1)/2n
- wherein t is the thickness of the vibrator portion and m is an integer less than or equal to n.
The combination of a piezoelectric resonator and a voltage source, the combination comprising:
- a piezoelectric resonator using a thickness extensional vibration mode, the piezoelectric resonator comprising a vibrator portion made up of n layers of piezoelectric thin-film, n being an integer greater than or equal to 2, each of the piezoelectric thin-film layers being separated by a respective insulating thin-film layer;
- and
- a voltage source for applying alternating voltages to the piezoelectric resonator in such a manner that the predominant vibration mode excited in the piezoelectric resonator is a higher-order vibration mode.
A method for exciting a piezoelectric resonator in a thickness extensional vibration mode, the piezoelectric resonator comprising a vibrator portion made up of n layers of piezoelectric thin-film, n being an integer greater or equal to 2, each of the piezoelectric thin-film layers being separated by a respective insulating thin-film layer, the method comprising:
- applying alternating voltages to the piezoelectric thin film layers in such a manner that the predominant vibration mode excited in the piezoelectric resonator is a higher-order vibration mode.
Dependencies are inferred from the claim text.