Disclosed is a switch mode power amplifier that provides high power (e.g., 100 W) at a high frequency (e.g., microwave frequency range). The switch mode power amplifier includes a load resistor, an inductor-capacitor (LC) circuit connected in parallel with the load resistor, a first switching mechanism connected to a first endpoint of the load resistor, and a second switching mechanism connected to a second endpoint of the load resistor. In one embodiment, the LC circuit is a first LC circuit connected in parallel with the load resistor and a second LC circuit is connected in series with the first LC circuit (and therefore connected in parallel with the load resistor). The circuit is transformer free.