Equivalent circuit constants of rectangular piezo-electric ceramic resonators with electrode devided into two

Abstract

Vibration analysis of piezoelectric ceramic resonators which have rectangular shape and two electrode-pairs are made in order to investigate the effect of unelectroded area on the eqivalent electical circuit constants. The finite-element-method applying rectangular elements is used in analyses to deal with the vibration of resonators as two demensional problem and to consider the difference in elastic constants between electroded and unelectoded areas. The principal results obtained for two types of resonators with electrode devided longitudinally and laterally into two are as follows. The resonant frequencies become higher with increase of unelectroded area. In case of the resonator with longitudinally devided electrodes, this effect is almost linear for longitudinal modes and little for flexuial modes. This effect also becomes less as increasing the ratio of width to length. The ratios of capacitance varies up to three figures with unelectroded area and become minimum at certain unelectrode area for several modes