A topology often favored for generating modest amounts of microwave power output is to combine the outputs of several relatively low output power amplifiers. The individual amplifiers usually have a “distributed” or “traveling wave” topology1. The distributed amplifier topology achieves a large frequency range by arraying individual transistors; each representing shunt capacitances between series inductances, to create a semi-lumped representation of a transmission line (see Figure 1). This amplifier topology is often fabricated using MMIC techniques, and has been optimized to the point where single amplifiers can provide up to nearly 1 Watt of saturated power output. Nevertheless, it is no trivial task, using conventional planar circuit techniques, to combine the power output of even a small number of these distributed amplifiers over a full decade frequency range, without incurring unacceptable losses or poor flatness characteristics.