DUPLEXER HAVING SURFACE ACOUSTIC WAVE FILTERS FORMED ON ONE SUBSTRATE

摘要

PURPOSE: A duplexer having surface acoustic wave filters formed on one substrate is provided to reduce crosstalk by forming different kinds of surface acoustic wave filters on an identical substrate. CONSTITUTION: A duplexer includes a ladder filter and a multimode filter that are formed on an identical surface of a predetermined substrate(10). A first comb-like electrode of the ladder filter and a second comb-like electrode of the multimode filter have an identical layer structure with an equal film thickness. The first comb-like electrode and the second comb-like electrode are formed with single-layer films mainly containing aluminum.