Method and apparatus for reducing interfering signals in a transmitter

An interference canceller 200 and corresponding method thereof operates to reduce the level of an interfering signal and includes a circulator 202 comprising a transmitter port, a receiver port and an antenna port, a transmission line 210 comprising a first end coupled to the transmitter port and a second end for coupling to a signal source; and a circuit 216 , having an input coupled to the receiver port 206 and an output coupled 220 to the transmission line, for providing a phase shifted version of a signal coupled to the input at the output, wherein an interfering signal at the antenna port is reverse coupled to the transmission line by the circulator and coupled to the input of the circuit so as to reduce an amplitude of the interfering signal at the second end 212 of the transmission line. The interference canceller concepts may advantageously be used in a single transmitter version or in a multiple transmitter version (FIG. 4 ).