Manufacture of Quartz Crystal Filters

represent the mass and elasticity of the plate, respectively, while the shunt condenser represents the capacitance between faces of the crystal. The damping of such a plate may be made very low, giving a ratio of reactance to resistance (commonly termed Q) of 15,000 or 1 Fig. 1--Equivalent circuit of a quartz crystal plate. Elements L, C and R are associated with the piezo-electric property and mechanical resonance of the crystal, while Co represents capacitance between the electrodes.