Abstract: The present invention provides a single chain power amplifier for a multi-mode and/or multi band wireless communication. The power amplifier comprise switchable input, inter-stage and output matching networks as well as active periphery adjustable driver stage power device and power stage power device. Switches and bias are configured for each frequency band and/or wireless communication standard. A driver stage power device, switches, control and bias circuitry, input matching, inter-stage matching and a part of output matching is fabricated on CMOS Silicon On Insulator process (SOI), while a power stage power device maybe fabricated by Gallium Arsenide (GaAs) processing.