GB609717A - Electron discharge devices using a deflected beam - Google Patents

Abstract

609,717. Electron discharge apparatus. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. March 1, 1945, No. 5187. Convention date, March 6, 1942. [Class 39 (i)] An electron discharge device amplifier of the beam deflection type has an output electrode system comprising a quarter-wave coaxial line section with the inner and outer conductors connected together at one end, the other end being closed for radio-frequency by an apertured part, the electrons passing through the aperture to be collected by the inner conductor. In the construction shown in Fig. 1, the beam of electrons passes through apertured electrodes 14 and 15 and is deflected by the electrodes 16 and 17 across the aperture 19<1> and across the gap 19<11> to be collected by the inner surface of the tubular inner conductor 18 of the quarterwave coaxial line constituted by the inner conductor 18 and the outer conductor 13, whereby secondary emission is suppressed. A radiator or coupling loop 20 extends through the envelope 10 and an aperture in the outer conductor 13 of the quarter-wave coaxial line and is connected to the inner conductor 18. The output and input electrodes are shielded from each other and from the output and input circuits by the construction shown. For maximum impedance the ratio of the diameters of the outer and inner tubes 13 and 18 is approximately 9 to 1 and for very high impedance the diameter of the outer tube 13 is approximately one-eighth of a wavelength. In the construction shown in Fig. 2, electrons from the indirectly heated concave cathode 31 pass through an apertured partition 34 in a cylindrical member 33 in an envelope 30 and are deflected by converging electrodes 36 and 37 across the apertured partition 35 to be collected by the electrode 32 connected by leads 38 to the inner tube 39 forming with the outer tube 40 and end walls 41 and 41<1> and resonant cavity coaxial line tank circuit of 'a quarter wavelength. Wall 41 and partition are capacitively coupled so that the end of the tank circuit is closed for radio-frequency voltages and currents except for the aperture 351. In the construction shown in Figs. 3 and 4, the beam of electrons passes from the indirectly heated cylindrical cathode 50 in the combined envelope and shielding cup 54 between converging electrodes 52 and 53 and through an elongated aperture 57<1> in the outer tube 57 to be collected by the inner tube 58 of a quarter wavelength coaxial line resonant cavity tank circuit. The envelope 54 and tube 57 are joined by an insulating collar 60. Leads and supports for the deflecting electrodes, and for the cathode and its heater, are sealed through beads in the envelope 54. The output is taken off by means of a conductor 61 passing through seal 61<1> in the outer tube 57.