Appraisal of the inverted-mesa AT-cut quartz resonator for achieving low-inductance high-Q single-response crystal units

A novel design for v.h.f. AT-cut quartz-crystal units is described which enables optimum energy-trapping conditions to be achieved with less restriction in the choice of equivalent electrical parameters than is usual for conventional units. The good suppression of unwanted modes, low inductance values and potentially good frequency stability of this type of unit should lead to its application in both oscillators and filters.