A Quartz Plate with Coupled Liquid Column as a Variable Resonator

The equivalent electrical constants of a combination resonator consisting of a piezoelectric X-cut quartz plate and a closely coupled liquid column have been experimentally investigated. The equivalent electrical constants of such a resonator were greatly changed and the resonant or oscillating frequency was shifted over a wide range (2.2 to 3.0 megacycles) by adjusting the length of the liquid column. In particular, the sharpness of resonance was found to vary from 400 for the plate, cemented to a holder but without the liquid column, to 4000 for the combination resonator.