ACOUSTIC WAVE DUPLEXER

An acoustic wave duplexer has a satisfactory isolation characteristic between a reception acoustic wave filter chip and a transmission acoustic wave filter chip, and includes a reception surface acoustic wave filter chip and a transmission surface acoustic wave filter chip mounted on a substrate. The substrate includes first and second balanced terminals and a common terminal. At least one of the transmission surface acoustic wave filter chip and the reception surface acoustic wave filter chip is a balanced filter unit that includes, as an input terminal or an output terminal, a first balanced signal terminal and a second balanced signal terminal. The acoustic wave duplexer further includes a first interconnection arranged to connect the balanced filter unit and the first balanced terminal and a second interconnection arranged to connect the balanced filter unit and the second balanced terminal. The first and second interconnections intersect with each other while being insulated from each other.