The sophisticated properties of the microwave oven magnetron

The magnetron commonly used in the microwave oven has unusually low noise and long life resulting from an internal feedback process that limits the emission from the cathode to optimum values for these properties. Without compromising these properties the magnetron can be combined with external circuitry to lock the output phase to the input phase and simultaneously provide 30 dB of gain. The operation of the microwave oven magnetron is discussed with respect to its low noise generation and the self-regulation of filament temperature to minimize noise and maximize long life. The operation of the magnetron as a high-gain, phase-locked amplifier is considered.<>