Due to the desire for lighter and longer lasting wireless devices, the need for efficient power amplifiers has become apparent. High efficiency greatly increases the useful battery life of the device in question, since the device will consumes less DC power for the same level of useful output power. The efficiency of an dir=ltr Beside, to decrease dimensions and eliminate undesirable harmonics in microwave structure like antennas, power amplifier, filters and etc., Defected Ground structure (DGS) have been noticed. These structure disturb current path in ground plane by creation a window in ground plane of micro strip line, so transmission line features such as line capacitance and inductance will be changed, which can be used control and eliminate undesirable harmonics. In this project at first, a comprehensive definition of dir=ltr Key words: ltr"