In this paper, a two-stage cascaded power amplifier (PA), which consists of cascode topology, for Multi-band systems operating in the 0.7–6GHz frequency range is presented. The shunt-shunt feedback and shunt peaking is used to improve wideband matching. To achieve sufficient linearity and efficiency, this PA operates in the Class-AB regime. It is designed in SMIC 0.13μm RF CMOS process. The proposed PA provides the following performance: S21 of 22-dB, more than 10-dB input and output return loss, 10.8% maximum power-added-efficiency and 10.65dBm output P1dB with at 3GHz. The PA works under 1.8v supply, the total area of the layout is 1.08×0.83 mm2.