A transmitter circuit includes at least one transmitting signal processing device, a compensation device and a compensation value calibration device. The at least one transmitting signal processing device sequentially generates multiple output signals according to multiple input signals. The compensation device sequentially generates the input signals according to multiple initial compensation values. The compensation value calibration device receives the output signals as multiple feedback signals and performs a calibration operation according to the feedback signals. The compensation value calibration device includes a digital signal processor coupled to the compensation device. In the calibration operation, the digital signal processor determines a first characteristic curve according to the initial compensation values and power of the feedback signals at a predetermined frequency, determines a first compensation value corresponding the minimum power according to the first characteristic curve and provides the first compensation value to the compensation device.