Provided is a transmitter. The transmitter includes a signal combiner configured to amplify a first differential radio frequency (RF) signal modulated to be transmitted through a first frequency band and a second differential RF signal modulated to be transmitted through a second frequency band non-adjacent to the first frequency band and summate the amplified first differential RF signal and the amplified second differential RF signal in a current mode to generate an RF signal and a power amplifier configured to amplify the generated RF signal.