Patent ID: 8339216

Claim:
A duplexer for separating a transmit signal (Tx) and a receive signal (Rx), the duplexer, comprising: a transmit filter for substantially forwarding the transmit signal within an at least one transmit band to an antenna; a receive filter for substantially forwarding the receive signal within at least one receive band from the antenna to a receive path; an analogue quadrature splitter adapted to split the transmit signal into an in phase component and a quadrature component; a first filtering element with a first filtering characteristic comprising at least one first pass band and at least one first stop band; a second filtering element with a second filtering characteristic comprising at least one second pass band and at least one second stop band; wherein the analogue quadrature splitter is adapted to increase an attenuation of the transmit signal outside the transmit band and wherein the transmit filter comprises a first transmit filter element upstream of the analogue quadrature splitter; and a second transmit filter element downstream of the analogue quadrature splitter.