| 摘要 |
A method of calibrating a transmit branch of a transmitter is provided. A low frequency component in a high frequency output signal of the transmit branch is measured. The low frequency component is present when the transmit branch is uncalibrated. From the measured low frequency component, a first compensation signal is derived. The first compensation signal is injected into an in-phase branch of the transmit branch. A second compensation signal is derived and injected into a quadrature branch of the transmit branch. The first and second compensation signals are swept and adapted on the basis of the measured low frequency component. From the sweeping, minimum values of the measured low frequency component are obtained. Thereafter, the first and second compensation signals are successively set at the minimum values. In addition to calibrating the transmit branch, in case of a transceiver, a receive branch may be calibrated. To calibrate the receive branch, the calibrated transmitter is coupled to the receive branch. Thereafter, the receive branch is calibrated through sweeping and setting of receiver branch parameters. |
