Patent ID: 8274342

Claim:
A duplexer comprising: a transmission filter connected between a common terminal and a transmission terminal; a reception filter connected between the common terminal and a reception terminal; a capacitor connected in parallel with the transmission filter and the reception filter between the transmission terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the transmission terminal to the reception terminal through the transmission filter and the reception filter and a signal passing from the transmission terminal to the reception terminal through the capacitor is a range of 180±85°, or connected in parallel with the reception filter between the common terminal and the reception terminal and has a capacitance so that a phase difference between a signal passing from the common terminal to the reception terminal through the reception filter and a signal from the common terminal to the reception terminal through the capacitor is a range of 180±85°; and a package on which the transmission filter and the reception filter are mounted, the package including the capacitor.