GB554202A - Improvements in or relating to electron discharge devices - Google Patents

Abstract

554,202. Electron-oscillators. PHILIPS LAMPS, Ltd. (Naamlooze Vennootschap Philips' Gloeilampenfabrieken). Dec. 18, 1941, No. 16373. [Class 39 (i)] In discharge devices of the kind in which an electron beam is velocity modulated by passing through a high frequency electric field and in which the variations in velocity are utilized either with or without conversion into density variations, the velocity control, or the output voltage, or both are effected in a field system of the magnetron or Barkhausen-Kurtz type, into which the beam is led obliquely to the axis of the system. As shown in Fig. 1, the electron stream from a gun 2 is deflected by electrostatic or magnetic means 4, so as to enter obliquely to the axis, the high frequency field established by two semicylindrical electrodes 3. Under the action of an axial magnetic field and the alternating potentials applied to the electrodes, the electrons describe helical paths of increasing or decreasing tangential velocities according to the phase at which they enter the field. On emergence, the electron stream is deflected by the means 7, similar to 4, through the drift space 8, where they are formed into groups of varying density, which are utilized to produce an output voltage by passing through a similar system 9, 10, 11, the electron stream being collected by an anode 14. The device may be used for amplifying, generating, modulating or mixing oscillations. For deflecting, the drift space 8 and system 9, 10, 11 are omitted and the density modulated beam, made to impinge on a collecting electrode, the potential of which is adjusted to reflect the slower moving electrons. Phase and frequency changing may be effected by using systems in the modulating and energy abstracting regions having different numbers of anodes ; and mixing by applying the oscillations of different frequencies to any' of the electrodes. For oscillation generating, the output may be fed back to the velocity modulating system, or the latter may be in circuit with a negative resistance. In a modification, Fig. 2 (not shown), the retarding field is of the Barkhausen-Kurz type with the cathode removed, the electron beam in this case following a zig-zag path in the field.