RF amplifier with automatic impedance matching system

A topology of a RF amplifier (1.8 GHz) with an automatic impedance matching system is presented. This RF amplifier, under impedance load mismatch, is capable of reducing the variation of its output power. Simulation results show that, with a load mismatch of up VSWR 5.7:1, the amplifier output power varies between 12.3 and 21 dBm. Incorporating an automatic impedance matching system to the amplifier, a range of output power between 15 and 18.8 dBm is obtained.