Patent ID: 8526533

Claim:
A method of measuring I-Q mismatch in a system having a transmitter, the transmitter comprising an in-phase up-converter, a quadrature-phase up-converter, and a power detector, the method comprising: measuring an in-phase transmit power at the power detector caused by transmitting an in-phase output signal to the in-phase up-converter; measuring a quadrature-phase transmit power at the power detector caused by transmitting a quadrature-phase output signal to the quadrature-phase up-converter; calculating a transmitter-gain-mismatch as a function of the in-phase transmit power and the quadrature-phase transmit power; measuring an I-Q transmit power at the power detector caused by simultaneously transmitting a gain-mismatch-compensated in-phase output signal to the in-phase up-converter and a gain-mismatch-compensated quadrature-phase output signal to the quadrature-phase up-converter; and calculating a transmitter-phase-mismatch as a function of the I-Q transmit power, wherein the step of calculating the transmitter-gain-mismatch comprises solving the equation G 13 m =√{square root over (P I /P Q )}, where G 13 m , is the transmitter-gain-mismatch, P I is the in-phase transmit power, and P Q is the quadrature-phase transmit power.