GB745729A - Improvements in or relating to resonant cavity magnetrons - Google Patents

Abstract

745,729. Magnetrons. M-O VALVE CO., Ltd., KETTLEWELL, E., WILLSHAW, W. E., BOOT, H. A. H., and BUCKINGHAM, J. Nov. 18, 1953 [Aug. 19, 1952; Oct. 2, 1952], Nos. 20840/52 and 24690/52. Class 39 (1). In a multi-cavity magnetron the output coupling means is connected symmetrically to each of a plurality of points in the anode system, these points being evenly spaced round the cathode. In the embodiment shown in Fig. 1 of the drawings accompanying the first Provisional Specification alternate anode segments are connected to a spider 19 (Fig. 3) connected to a metal rod 20 which radiates into two waveguide sections; one of the sections 24 leads through a window 27 to an output, and the other may be used to provide a second output or, as shown, may be short-circuited at one end and used for matching or tuning purposes. Anode straps 18 may be provided at the opposite end of the anode from the spider. The magnetron is provided with cooling means (not shown) such as radiator fins or water-cooling means. In the embodiment shown in the Figure accompanying the second Provisional Specification the anode block A is about one wavelength long and alternate anode segments are provided with studs F connected to a conductor G which forms the inner conductor of a coaxial line, the outer conductor being the part H of the envelope. One end of conductor G forms a probe which radiates into a waveguide J, one end of which is closed a quarter-wavelength from the probe and the other end of which provides the power output. The part H of the envelope fits into a socket M in a magnetic pole piece N. The ring P can be used, by appropriate dimensioning in designing the magnetron, to adjust the degree of coupling between the resonator and the output coaxial line. Anode straps may be provided at the opposite end of the anode. A magnetron may be provided with two symmetrical output coupling means, one at each end of the anode block, and one of them may be used for tuning purposes being connected, for example, to a waveguide of variable effective length; the tuning means may be operated by a flexible bellows forming part of the envelope.