Illustrative embodiments of a power amplifier are disclosed which include a plurality of amplifier cells, each having an input and an output. The plurality of amplifier cells are formed on a semiconductor substrate such that the outputs of the plurality of amplifier cells are electrically coupled in series. Each of the plurality of amplifier cells may comprise a first transistor that is electrically insulated from the semiconductor substrate and a first feedback resistor configured to dynamically bias the first transistor.