Transceivers having loopback switches and methods of calibrating carrier leakage thereof

A transceiver comprising:

• a transmitter circuit configured to, in a normal mode, up-convert a transmission digital signal to generate a first transmission signal, the transmitter circuit being further configured to, in a calibration mode, perform a digital-to-analog conversion (DAC) operation on a calibration code without the transmission digital signal to generate a calibration signal, change a bias of a mixer in response to the calibration signal, and output a carrier signal of an oscillator as a second transmission signal;
• a receiver circuit configured to, in a normal mode, down-convert a receiving signal received from an antenna to generate a first receiving digital signal, the receiver circuit being further configured to, in the calibration mode, down-convert the second transmission signal to generate a second receiving digital signal;
• and
• a loopback switch configured to electrically connect an output terminal of the transmitter circuit with an input terminal of the receiver circuit in the calibration mode.