GB610969A - Improvements relating to electron discharge devices for amplifying oscillations of very high frequency - Google Patents

Abstract

610,969. Velocity-modulated tubes. COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. April 17, 1946, No. 11909. Convention date, Dec. 26, 1940. [Class 39 (i)] An amplifier for use at frequencies of about 300 mcs./sec. comprises a velocity modulator, a repeller electrode and an electron multiplier. In the Figure, the electrons pass from the cathode F and control grid G to the electrodes D1, D2, M which form a velocity modulation system. Electrode A1 is near cathode potential and thus passes the fast electrons, but repels the slow ones back to D2. The electrons then impinge on the secondary emitting electrode C2 and the secondary electrons are focused by the ring electrode B2 which is near cathode potential; the process is repeated and the output taken from A3. The electrode spacing may be such that the transit time of the electrons between two cathodes C2 is half a period. The repeller electrode A1 may itself be a secondary-emitting grid. In another form, Fig. 2 (not shown), the electron multiplier is of the zig-zag type and the electrodes C2 are parallel plates.