Patent ID: 8022787

Claim:
A duplexer, comprising: a receiving filter or receiving filters that let(s) a reception signal in a receiving band pass; a transmission signal terminal into which a transmission signal in a transmitting band that is different from the receiving band can be input; a common terminal with which input of the reception signal in the receiving band and output of the transmission signal in the transmitting band can be performed; a hybrid that has a plurality of first terminals and a plurality of second terminals, and that splits a signal that is input from one of the first terminals with a phase difference and outputs the split signals to the second terminals; wherein the common terminal and the transmission signal terminal are respectively connected to the first terminals; wherein the receiving filter(s) is/are connected to the second terminals; wherein the hybrid outputs split signals that is input from one of the first terminals and is split with a phase difference of 90° to the second terminals, and wherein the duplexer further comprises a phase shifter that shifts the phase of at least one of the reception signals that is input from the common terminal to the hybrid and is output with a phase difference of 90° from the second terminals, setting said phase difference to 180°.