GB625902A - Improvements in magnetrons - Google Patents

Abstract

625,902. Magnetrons. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. May 7, 1946, No. 13825. Convention date, March 22, 1945. [Class 39 (i)] [Also in Groups XL (b) and XL (c)] A magnetron comprises an anode block 10, Fig. 2, defining a plurality of cavity resonators, alternate anode segments are connected by straps 25, 26 and intermediate anode segments by straps 25<1>, 26<1>, and a tunable resonator is coupled to one of the straps 25 for varying the oscillation frequency. The tunable resonator is preferably a coaxial line 30, 31 tuned by either (a) a piston 38, (b) by varying the length of the inner conductor 31 by making it in two telescoping parts, Fig. 3 (not shown), (c) by varying a capacitance connected to the coaxial line, or (d) by tuning a cavity resonator coupled to the coaxial line. Power is taken out by a loop 21 forming an extension of the inner conductor 21<1> of a coaxial line, the outer conductor 22 of which is screw-threaded at 24 so that the coaxial line can be connected to an extension which may couple the' device to a radiator. The anode may be (a) a block with slots which may or may not be enlarged at their outer ends, or (b) vanes or slats supported by a conductive ring, In the former case the straps 25, 26 ; 25<1>, 26<1> are at opposite ends of the anode block. - In the latter case, ring strapping may be used, one conductor of the coaxial tuning line being coupled to one ring and the other conductor to the other ring. The tuning line and output line are preferably less than 90 degrees apart to suppress spurious modes. The device may be frequency modulated by means of a tunable coaxial line 40, 41 energized by a modulating circuit 42 and coupled to strap 26. Prior art arrangements for tuning resonators of magnetrons involving movable parts within the resonators or elsewhere within the envelope are referred to. Specification 588,916 is referred to.