Inventors:
Kenji Uchino - State College PA
Burhanettin Koc - State College PA
Assignee:
The Penn State Research Foundation - University Park PA
International Classification:
H01L 4108
Abstract:
A piezoelectric transformer using a piezoelectric annulus, divided into sections, includes at least one input and one output electrode configuration. The input electrodes are formed by covering top and bottom surfaces of the divided section of piezoelectric annulus. The low impedance portions, which are input regions, are poled parallel to the thickness direction and the high impedance portions, which are output regions, are poled tangentially. The transformer is operable at several radial mode resonance frequencies of piezoelectric ring. Two stepped up ac output voltages, in phase or 180 degree out of phase, can be obtained at several resonance frequencies of the piezoelectric annulus. The transformer is also operable as a step-down transformer by inverting the input and output ports.