An integrated circuit for cancelling a radio frequency transmit leakage signal, wherein the integrated circuit comprises: a transmitter portion comprising at least one amplifier stage for transmitting a radio frequency signal to an antenna port; and a first coupler arranged to operably couple the transmitter portion, the antenna port and a receiver portion; wherein the receiver portion is arranged to receive a first composite signal that comprises a received radio frequency signal from the antenna port and a transmit leakage signal and the receiver portion comprises: a first down-conversion circuit arranged to receive the first composite signal and a local oscillator signal such that the first down-conversion circuit outputs a down-converted first composite signal at a first intermediate frequency signal; at least one phase shifter circuit arranged to receive the local oscillator signal and to generate a phase shifted version of the local oscillator signal to cancel at least a portion of the transmit leakage signal from the down-converted first composite signal; and a second coupler arranged to receive the down-converted first composite signal at the first intermediate frequency signal and the phase shifted version of the local oscillator signal to produce a transmit leakage cancelled signal. a transmitter portion comprising at least one amplifier stage for transmitting a radio frequency signal to an antenna port; and a first coupler arranged to operably couple the transmitter portion, the antenna port and a receiver portion; wherein the receiver portion is arranged to receive a first composite signal that comprises a received radio frequency signal from the antenna port and a transmit leakage signal and the receiver portion comprises: a first down-conversion circuit arranged to receive the first composite signal and a local oscillator signal such that the first down-conversion circuit outputs a down-converted first composite signal at a first intermediate frequency signal; at least one phase shifter circuit arranged to receive the local oscillator signal and to generate a phase shifted version of the local oscillator signal to cancel at least a portion of the transmit leakage signal from the down-converted first composite signal; and a second coupler arranged to receive the down-converted first composite signal at the first intermediate frequency signal and the phase shifted version of the local oscillator signal to produce a transmit leakage cancelled signal. a first down-conversion circuit arranged to receive the first composite signal and a local oscillator signal such that the first down-conversion circuit outputs a down-converted first composite signal at a first intermediate frequency signal; at least one phase shifter circuit arranged to receive the local oscillator signal and to generate a phase shifted version of the local oscillator signal to cancel at least a portion of the transmit leakage signal from the down-converted first composite signal; and a second coupler arranged to receive the down-converted first composite signal at the first intermediate frequency signal and the phase shifted version of the local oscillator signal to produce a transmit leakage cancelled signal.