Multi-channel radio frequency (RF) transmitter (100) and method of calibrating the transmitter are provided. In an embodiment, the method involves applying an intermediate frequency (IF) signal with different compensation values on a first phase rotator (128) in a first channel transmitter module (TX1) of the transmitter, wherein the different compensation values are designed to compensate for a particular phase influencing factor, applying phase codes with the same different compensation values for different phases on a second phase rotator (132) in a second channel transmitter module (TX2), measuring resultant phase errors due to phase errors of the first and second channel transmitter modules for the different compensation values, and based on the resultant phase errors, selecting one of the different compensation values to be used as a calibrated compensation value for the first and second phase rotators in the first and second channel transmitter modules to compensate for the particular phase influencing factor.