Piezoelectric vibrator for suppressing harmonic vibrations of lower orders

摘要

A unit for suppressing harmonic vibration of a lower order which does not have desired frequency in an overtone resonator consisting main electrodes and sub electrodes. Harmonic vibration of a lower order suppressing piezoelectric vibrator comprises main electrodes arranged on a piezoelectric substrate and sub electrodes arranged in the vicinity of the main electrodes with gaps provided therebetween. If the electric equivalent circuit of the resonator is expressed by a coupling circuit which connects in series a circuit, which connects in parallel a series resonance circuit by the sub electrodes and coupling capacity indicating that the main electrodes are coupled with the sub electrodes, to a series resonance circuit by the main electrodes, then their loop frequencies substantially coincide with each other.