GB955695A - Improvements in or relating to travelling wave tube devices - Google Patents

Abstract

955,695. Travelling-wave tubes. RAYTHEON CO. Nov. 24, 1960, No. 40457/60. Heading H1D. In a crossed-field type travelling wave beam tube the electron beam is injected into the interaction space along a cycloidal path and is initially density modulated by a process of " electron sorting " whereby unfavourable electrons are removed at one or points along the interaction structure held at a negative potential either along the sole electrode 51, Fig. 7, or along the delay line 63, Fig. 8. In each case a field perturbing electrode 62, Fig. 7, or 71, Fig. 8, may be provided to cause the beam to follow a rectilinear path. Alternatively the magnetic field may be locally distorted. In other embodiments the delay line may be replaced by a density modulated beam as a wave circuit element or a delay line is provided on each side of the interaction space or the travelling-wave tube may have a circular or a coaxial structure. The delay lines may be of the interdigital or disc-loaded types and may support backward or forward waves. The tube may be operated as an oscillator or as an amplifier and may be pulsed to produce amplitude or frequency modulation. The sole electrode may be liquid cooled.