An investigation into development of a 200-kW CW solid state rf power system design to replace the existing klystron-based 352-MHz rf systems at the Advanced Photon Source has been started. The baseline 352-MHz solid state system design will consist of multiple 1-kW CW modules combined to produce a total output capability of 200-kW CW, sufficient to drive one single-cell storage ring cavity. A description of the 1-kW CW module building block of the solid state power sistem will be presented, along with results from hardware evaluation tests at the 1-kW CW level.