LOW-NOISE, CROSSED-FIELD DEVICES SUCH AS A MICROWAVE MAGNETRON, MICROWAVE OVEN UTILIZING SAME AND METHOD OF CONVERTING A NOISY MAGNETRON TO A LOW-NOISE MAGNETRON

摘要

Low-noise, crossed-field devices such as a microwave magnetron, a microwave oven utilizing same, crossed-field amplifier and a method of converting a noisy magnetron to a low-noise magnetron utilize an azimuthally varying, axial magnetic field. The magnetic configuration reduces and eliminates microwave and radio frequency noise. This microwave noise is present near the carrier frequency and as sidebands, far separated from the carrier. The device utilizes azimuthally varying, axial, magnetic field perturbations. In one embodiment, at least one permanent magnet (10) placed against the azimuthally-symmetric, axial magnetic field magnetron magnets (12) (four magnets work especially well). This additional permanent magnet(s) (10) causes the axial magnetic field to vary azimuthally in the magnetron and completely eliminates the microwave noise and unwanted frequencies.