Thin film piezoelectric vibrator and thin film piezoelectric bulk acoustic wave resonator and a high-frequency filter using the same

摘要

PROBLEM TO BE SOLVED: To improve a Q value of resonance characteristics in a wide band resonator capable of controlling a frequency by a shape, and to provide the wide band resonator inexpensively.;SOLUTION: A thin film piezoelectric bulk wave high frequency resonator comprises a laminated structure including a piezoelectric thin film and first and second metal electrode films which exist so as to have the piezoelectric thin film at least partially interposed therebetween, and all of resonance parts and a coupling part are formed on an insulating substrate by a thin film manufacturing device, and the resonance parts oscillate in a Radial Extension mode taking centers as nodes, and piezoelectric thin films of two resonace parts are polarized in a direction perpendicular to film surfaces, and the width of the coupling part is ≤1/4 of the width of the two resonance parts.;COPYRIGHT: (C)2008,JPO&INPIT