New type of cavity resonator for piezoelectric surface excitation of acoustic waves at microwave frequencies

A description is given of a method of exciting acoustic waves in a piezoelectric crystal using a double-tuned cavity resonator. At one resonant frequency the electric field is sensibly tangential to the crystal surface, while, at the other resonance, this field is essentially normal to the crystal surface. In contrast to previous methods of excitation, this leads to good exponential decay over a large number of successive reflections in the crystal rod.