CROSS ELECTROMAGNETIC FIELD TYPE MICROWAVE AMPLIFYING TUBE

摘要

PURPOSE:To attenuate microwave components coming back as electromagnetic waves to prevent a needless oscillation and perform stable amplifying operation, by forming a circuit separator surface facing to a cathode with a material having large electrical resistivity than that of copper. CONSTITUTION:In a cross electromagnetic field type microwave amplifying tube CFA, the outside of a hollow cylindrical cathode 11 is surrounded concentrically by low speed wave circuits 12, and on a surface facing to the cathode 11 of a circuit separator 16, interposed between the input terminal 13 and the output terminal 15, is equipped with a thin plate 17 made of a high resistivity material. In this CFA having the circuit separator 16 in such structure, microwave components, which propagate as electromagnetic waves directly back to the input terminal 13 from the output terminal 15 of the low speed wave circuit 12 and contribute to a needless oscillation, are largely attenuated by an increase in electrical resistance loss for high-frequency current flowing along the surface of the thin plate 17. Hence, the needless oscillation of the microwaves is prevented and operational stability is much improve.