Patent ID: 9749172
Date: 2017-08-29
CPC Classifications: H04B,H04L

Claim:
1. A calibration method for calibrating a transmitter, wherein one of the first signal path and the second signal path is an in-phase signal path and the other one of the first signal path and the second signal path is a quadrature signal path, the calibration method comprising: additionally setting at least a calibration coefficient in the transmitter; setting the at least a calibration coefficient as at least a first eliminating value, and utilizing the transmitter to transmit a first test signal via the at least a calibration coefficient and via the first signal path and the second signal path to generate a first transmitting signal, wherein the first test signal has a specific frequency; loopbacking the first transmitting signal, and performing a spectrum analyzing operation on the first transmitting signal to generate a first spectrum analyzing result; setting the at least a calibration coefficient as at least a second eliminating value, and utilizing the transmitter to transmit a second test signal via the at least a calibration coefficient and via the first signal path and the second signal path to generate a second transmitting signal, wherein the second test signal has a specific frequency; loopbacking the second transmitting signal, and performing a spectrum analyzing operation for the second transmitting signal to generate a second spectrum analyzing result; and calculating at least a target eliminating value according to the first eliminating value, the second eliminating value, the first spectrum analyzing result, and the second spectrum analyzing result, and setting the at least a calibration coefficient as the at least a target eliminating value; wherein the at least a calibration coefficient is set as the at least a target eliminating value to calibrate the mismatches between the first signal path and the second signal path of the transmitter, and the at least a calibration coefficient only has a single calibration coefficient, and the step of utilizing the transmitter to transmit the first test signal via the at least a calibration coefficient and via the first signal path and the second signal path adds the first test signal with its complex conjugate multiplying the calibration coefficient and transmits it via the first signal path and the second signal path.