A power amplifier core (40) for amplifying RF signals is provided. The power amplifier core (40) includes a first string of FET cells (46) for amplifying the RF signal. The FET cell string includes at least two FET cells (46) connected in series with an output port (48) of the amplifier core. A bias network (44) coupled between an amplifier core input port (42) and the FET cells (46) couples the RF signal to the FET cells (46). The bias network (44) includes a bias capacitor (50) and a resistor network. The bias capacitor (50) is coupled to the input port (42) for AC coupling the RF signal to an associated FET cell (46) in the FET cell string. The resistor network is coupled from the bias capacitor (50) to the associated FET cell (46) for providing a DC bias to the associated FET cell (46).