Abstract: A coaxial magnetron has a high-Q resonant cavity surrounding a multiple-resonator anode circuit and coupled by slots to alternate anode resonators. The cavity is resonant in the TE.sub.111 mode, having two zero points of electric field on its periphery. The anode circuit is correspondingly resonant in its N/2-1 mode.Mode suppression means damp out the degenerate TE.sub.111 mode which is not coupled to the output iris.The size and weight of the magnetron are much less than conventional tubes using a cavity resonant in the TE.sub.011 mode with circular electric field.

Abstract: A permanent magnet structure particularly beneficial for generating the interaction field in coaxial, crossed field electron tubes is designed such that the normal iron flux return path is not required. Substantial reduction in weight results. A further benefit is that a magnetron interaction structure including the magnets may be built as a unit replaceable in the field in a stabilizing cavity structure. Since the cavity structure contains no iron, the magnets are not demagnetized in the replacement process and there are no mechanical mounting problems caused by magnetic forces.