Energy Trapping of Higher-Harmonic Width Vibrations in Piezoelectric Strips and Its Application to Filters.

The energy trapping of the higher-harmonic width-extensional and width-shear vibrations in a piezoelectric ceramic strip is studied based on the dispersion characteristics of these modes. By the use of energy trapping of the higher-harmonic width vibrations, new small-sized trapped-energy resonators and filters that can be used at the high-frequency range beyond several megahertz are developed. In the resonator and filter using a higher-harmonic width vibration, it is necessary to excite strongly the width vibration of a specific order and to suppress all other vibrations. In this paper, a new electrode configuration is proposed for this purpose by taking into account the stress distribution of the mode. In addition, this method is used for fabrication of 4.5 and 10.7 MHz trapped-energy filters using the 3rd-harmonic width-extensional vibration and the trapped-energy resonators using the 2nd, 3rd- and 4th-harmonic width-extensional vibrations. [ABSTRACT FROM AUTHOR]