Abstract: An automatic protection system for receiver circuitry includes a waveguide switch having a permanent magnet attached to a rotatable manifold and at least one electromagnet axially surrounding the rotatable manifold. An automatic actuation circuit is coupled to the waveguide switch. The automatic actuation circuit includes an RF power detector for detecting incident RF power around the rotatable manifold and generating a detection signal therefrom, a controller coupled to receive the detection signal and for generating at least a first control signal based on the detection signal, and a magnet current driver coupled to receive the first control signal and coupled to the electromagnet. The magnet current driver provides a first drive signal responsive to the first control signal that automatically rotates the rotatable manifold into a protected position that implements a protected path, such as when the incident RF power exceeds a predetermined RF power level.