In general, in accordance with an exemplary aspect of the present invention, an electrical system configured to use power combining of microwave signals, such as those from monolithic microwave integrated circuits or MMICs is provided. In one exemplary embodiment, the system of the present invention further comprises a low loss interface that the circuits are directly connected to. In another exemplary embodiment, the circuits are connected to a pin which is connected to the low loss interface. In yet another exemplary embodiment of the present invention, a multi-layer power amplifier is provided that comprises two or more chassis and circuits attached to impedance matching interfaces according to the present invention. This multi-layered power amplifier is configured to amplify an energy signal and have a significantly reduced volume compared to existing power combiners.