Abstract: A pulse width modulation type power supply modulator capable of operating at high switching frequencies (>10 MHz) is achieved by eliminating resonant circuits which limit the maximal switching frequency. The modulator includes a power circuit including a power transistor, a first control circuit connected to the gate of the power transistor and a second control circuit connected to the output of the power circuit. In a preferred embodiment the active components are isolated from each other by areas of metalization on a printed circuit to minimize unwanted coupling and the electrical lengths are minimized.