Patent ID: 8879677

Claim:
A method for compensating a mismatch of an in-phase (I) signal and a quadrature (Q) signal of a receiver, wherein the receiver comprises: a first channel, comprising: a first mixer, for mixing a received signal with a first local oscillation signal to generate a first signal; a first multiplier, coupled to the first mixer, for generating an adjusted first signal according to the first signal; and an adder, coupled to the first multiplier; a second channel, comprising: a second mixer, for mixing the received signal with a second local oscillation signal to generate a second signal; and an adjustable delay unit, coupled to the second mixer, for delaying the second signal to generate a delayed second signal; and a second multiplier, coupled between the adjustable delay unit and the adder, for generating an adjusted second signal according to the delayed second signal, wherein the adder adds the adjusted first signal and the adjusted second signal to generate a compensated first signal; wherein the compensated first signal is one of the I signal and the Q signal, and the delayed second signal is the other one of the I signal and the Q signal; and the method further comprising: disabling the adjustable delay unit; receiving a first test signal to serve as the received signal to determine a first group of factors of the first multiplier and the second multiplier according to an image rejection ratio (IRR); receiving a second test signal to serve as the received signal to determine a second group of factors of the first multiplier and the second multiplier according to another IRR; and calculating a delay amount of the adjustable delay unit according to the first group of factors and the second group of factors.