Elongated drift field with a plurality of amplifier roehre in the electron beam direction and located one behind the other, are coupled to one another only electronically verzoegerungsleitungsabschnitten

摘要

969,291. Travelling wave tubes. HUGHES AIRCRAFT CO. Dec. 17, 1962 [March 22, 1962; March 29, 1962], No. 47514/62. Heading H1D. The invention relates to the isolator sections of a travelling wave tube in which the slow wave structure is severed into a plurality of amplifying sections arranged along the electron stream and has a construction generally similar to that described in Specification 879,997. In one arrangement, Fig. 2, the isolator section is formed in substantial continuity of the magnet-spacer assembly, but modified spacers 62, 64 and corresponding magnet discs are used to provide a larger substantially rectangular cavity as in either Fig. 3 or Fig. 4 (not shown). The centre polepiece 35 has no coupling hole, and the cavities contain wedges 74, 80 of lossy material to absorb the circuit wave energy. Suitable lossy materials are: a mixture of forsterite and silicon carbide; silicon carbide and either alumina or tale or beryllia. A similar isolating section for a solenoid focused tube is illustrated with reference to Figs. 5, 6, 7 (not shown). In two further arrangements, Figs. 8 and 9 and Figs. 10 and 11 (not shown), the slow wave structures terminate in waveguides with stepped lossy attenuators.