Patent ID: 7072614

Claim:
A communication device comprising: a transmitter, a receiver, the transmitter and receiver being coupled to an antenna respectively via a transmitter output and a receiver input, and a signal corrector that is configured to reduce a transmitter leakage signal at the receiver input, characterized in that the signal corrector comprises a transmitter leakage signal amplifier that is configured to selectively amplify the transmitter leakage signal, wherein a transmitter signal reference input of the amplifier is coupled to the transmitter output, a transmitter leakage signal input of the amplifier is coupled to the receiver input, and a transmitter leakage signal output of the amplifier is coupled to the transmitter leakage signal input to provide a negative feedback of the transmitter leakage signal occurring at the receiver input, characterized in that the transmitter leakage signal amplifier comprises: a phase splitter, a first demodulator and a second demodulator, a first low pass filter and a second low pass filter a first modulator and a second modulator, and a phase inverter, wherein: an input of the phase splitter is coupled to the transmitter output, the phase splitter is configured to supply respectively in-phase and quadrature phase components of the transmitter output to reference signal inputs of the first and second demodulators, as well as to carrier signal inputs of the first and second modulators, the first and second demodulators include: transmitter leakage signal inputs in common with the transmitter leakage signal input of the signal corrector, and outputs coupled respectively through the first and second low pass filters to modulating signal inputs of the first and second modulators, an output of each of the first and second modulators is coupled in common to the receiver input and the transmitter leakage signal inputs of the first and second demodulators to form a feedback path to the receiver input, and the phase inverter is included in the feedback path to provide the negative feedback of the transmitter leakage signal occurring at the receiver input.