DC-Induced Piezoelectric Cubic PMN - PT / Piezoelectric Tetragonal PZT Epitaxial Stack Polarity Inverted Resonators for Frequency Switchable Filters

Polarity inverted resonators can excite high-order mode, whose resonant frequency is higher than that of fundamental mode of single-layered resonators even though entire film thickness is same. Therefore, polarity inverted ferroelectric stacks allow to switch resonant mode for frequency switchable filters. In this study, DC-induced piezoelectric cubic PMN-PT/ piezoelectric tetragonal PZT epitaxial stack resonators were obtained by RF magnetron sputtering. During the application of -36 V, the resonators excite fundamental mode at 327 MHz, whereas the resonators excite second mode at 779 MHz with +36 V applied. Frequency switching were successfully demonstrated by changing the direction of DC field which is less than the coercive field of tetragonal PZT layers.