A transmitter and a transmitting method of a wireless communication system are provided. The transmitter transmits RF signals using an outphasing scheme of converting one analog IF NC-EMS into two analog C-EMSs. In the transmitter, a baseband processor generates a baseband digital modulated I-signal and a baseband digital modulated Q-signal. A signal converter converts the baseband digital modulated I-signal and the baseband digital modulated Q-signal into a baseband analog modulated I-signal and a baseband analog modulated Q-signal. An IF processor up-converts the baseband analog modulated I-signal and the baseband analog modulated Q-signal to generate one analog IF NC-EMS. A signal component separator separates the analog IF NC-EMS into a first analog IF C-EMS and a second analog IF C-EMS. An RF processor up-converts the first analog IF C-EMS and the second analog IF C-EMS to generate a first analog RF C-EMS and a second analog RF C-EMS. A power amplifier amplifies powers of the first and second analog RF C-EMSs. An RF combiner combines the first and second analog RF C-EMSs having the amplified powers to generate one combined analog RF C-EMS.