SURFACE ACOUSTIC WAVE FILTER USING NEW PIEZOELECTRIC SINGLE-CRYSTALLINE SUBSTRATE

摘要

PURPOSE: A surface acoustic wave(SAW) filter using a new piezoelectric single crystalline substrate is provided which has low loss and has a wide bandwidth at a high frequency region. CONSTITUTION: The surface acoustic wave filter includes a piezoelectric single crystalline substrate and an input converter(Interdigital transducer) and an output converter formed on the piezoelectric single crystalline substrate. The chemical composition of the substrate is expressed as a chemical equation of x(A)y(B)z(C)-p(P)n(N). (A) is Pb(Mg1/3Nb2/3)O3 or Pb(Zn1/3Nb2/3)O3, and (B) is PbTiO3, and (C) is LiTaO3 or LiNbO3. (P) is a metal and (N) is a metal oxide. x is higher than 0.65 and lower than 0.98, and y is higher than 0.01 and lower than 0.34, and z is higher than 0.01 and lower than 0.1, and p and n are higher than 0.01 and lower than 5 respectively. The filter is for being used in a mobile communication or IMT(International Mobile Telecommunication)-2000.