Patent ID: 7808935

Claim:
A duplexer comprising: a first filter having a first signal input portion, a first signal output portion, a first ground portion connected to a parallel arm including at least one of a resonator and a capacitor, and having a predetermined passband; a second filter having a second signal input portion, a second signal output portion and a second ground portion, and having a passband higher than the passband of the first filter; a common terminal connected to the first signal output portion and the second signal input portion; a first interconnection connected to the first signal output portion and the second signal input portion; a second interconnection connected to the first ground portion; and a ground terminal connected to the first and second interconnections and the second ground portion and to be supplied with a ground potential, wherein the first and second interconnections are formed so that one of angles between an extending direction of part of the first interconnection and an extending direction of part of the second interconnection on a predetermined virtual plane is smaller than 90 degrees and a direction of current flow through the part of the first interconnection is opposite to a direction of current flow through the part of the second interconnection.