A device for measuring a reflection coefficient of an antenna by using a radio frequency (RF) feedback signal provided by a coupler based on an RF transmission signal provided to the antenna includes a feedback circuit configured to generate a baseband feedback signal by down-converting and filtering the RF feedback signal, and a signal processing device configured to control the down-converting, based on a target frequency band, process a baseband transmission signal and the baseband feedback signal to have the target frequency band, and calculate a reflection coefficient of the antenna corresponding to the target frequency band. The RF transmission signal is generated from the baseband transmission signal.