Improvements in or relating to cavity-resonator magnetrons

摘要

873,510. Magnetrons. ELECTRIC- & MUSICAL INDUSTRIES Ltd. Nov. 21, 1957 [Feb. 1, 1957], No. 3498/57. Class 39(1). In a cavity resonator magnetron, the body portion 7, Fig. 2, is made from a single cylindrical copper block and has a transverse circular bore 8 into which a separate cylindrical resonator portion is fitted. Body portion 7 has a waveguide output channel 14 disposed along its axis and communicating with bore 8. Two side walls of channel 14 are chamfered as at 17 to avoid sparking and the boss 15 is provided with an annular recess 16 forming a high frequency choke. The resonator system, shown in plan in Fig. 6, comprises a copper cylinder 18, recessed at both ends as at 19, with an axial bore 20 and cavities 21. The output is removed by a slot 22, preferably oblique to the axis of cylinder 18, which constitutes a transformer formed integrally with the resonator portion and which couples the resonator system to the waveguide channel 14. The ends of the slot 22 may be enlarged. The assembled magnetron is shown in Fig. 7, one end of block 18 rests against shoulder 9, the oblique output slot 22 shown in Fig. 6. being closed at one end by this shoulder and at the other by a copper ring 23. At steel sleeve 24 is brazed into bore 8, a cathode 25 is inserted in bore 20, and the magnet pole piece structures 12, 13 are inserted in the countersunk portions of block 7. Sleeve 24 and cylinder 26 together constitute the pole piece 13. The magnetron may be evacuated by way of a bore 27 in the cylinder 26. The waveguide output channel is sealed by a window 28 in a cup 29 which is brazed to a sleeve 30 which in turn is brazed to the boss 15.