GB977002A - Improvements in or relating to travelling-wave tubes - Google Patents

Abstract

977,002. Travelling-wave tubes. SIEMENS & HALSKE A.G. April 24, 1963 [April 25, 1962], No. 16103/63. Heading H1D. A travelling-wave tube comprises a delay line 2, Fig. 1, the axis of which occupies a helical path, and another electrode 3 which occupies a generally helical path and which follows the axis of the delay line, wherein the other electrode is constituted by a series of mutually spaced distinct electrode elements and wherein in operation an electron beam 1 is guided to follow the delay line by an electrostatic field in the form of a series of electrostatic lens fields set up between the delay line and the elements of the other electrode. The electrode elements of the other electrode may be connected directly into groups, e.g. of two elements, Fig. 4, adjacent groups being connected together by an inductance 6. A helical metal screening member 4 is preferably provided to shield adjacent convolutions of the structure, and the delay line is preferably constituted by a interdigitated line formed by a series of electrode elements in the form of three limbs of a rectangle which partly surround the electron beam and a fourth supporting limb attached to the screening member; the screening member may also support the elements of the other electrode by using insulating supports, alternatively an additional helical stay, Fig. 5 (not shown) may be provided. The tube may be cooled by enclosing the structure in a metallic envelope which is soldered to the screening member, the envelope being cooled by direct convection.