GB979623A - Ultra-high-frequency electron tube - Google Patents

Abstract

979,623. Velocity-modulated beam tubes. KABUSHIKI KAISHA HITACHI SEISAKUSHO. April 26, 1961, No. 15149/61. Heading H1D. An ultra-high-frequency electron tube comprises an electron gun 43, an electron collector 45, a plurality of cavity resonators 25, 26 immediately adjacent each other in series and so arranged that an electron beam passes through all the resonators in turn, and means for exciting adjacent resonators in opposite phase, adjacent resonators being mutually high-frequency coupled and the electron transit angle through each resonator being such that the beam conductance at the excitation frequency is negative. The electron transit angle in each resonator has a value (2n + ¢)# radians where n is zero or a positive integer. The output may be delivered to a coaxial line, Fig. 5 (not shown), or a harmonic output obtained from an output cavity resonator 32 resonant at a harmonic frequency; in the latter case, the coaxial line 35 is connected to an appropriate load to adjust the intensity of oscillation. An input signal may also be applied to the coaxial line 35. All the cavities are tunable by flexure of wall portions 25a, 26a, 32a. There may be three, four or more mutually coupled resonators, and reference is made to a single cavity resonator arrangement which is stated to be impracticable.