GB472896A - Improvements relating to electron multiplying electric discharge devices - Google Patents

Abstract

472,896. Electron multipliers. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Feb. 28, 1936, No. 6098. Convention date, Feb. 28, 1935. [Classes 39 (i) and 40 (v)] Relates to apparatus for amplifying, detecting or generating high-frequency oscillations comprising an electron multiplier with several grids 2 ... 4 between the cathode 1 and the anode 5 and with a magnetic field in the spaces between the electrodes 1 ... 4 so that the electrons move in curved paths and strike the grids obliquely. Tuning means such as Lecher wire systems 7 are now provided each between two adjacent grids so that the potentials of these two grids vary in phase opposition, and the arrangement is such that the time of transit of the electrons across the space between the two grids is an odd integral multiple of one half-period of the oscillations. As the potential of the grid 2 increases, the number of electrons flowing to it and so of secondary electrons leaving it increases and this increased emission arrives at grid 3 at a time when its potential is high and thus increases the electrons flowing to and given off by the grid 3, the action being cumulative. The electrodes may be concentric cylinders or plane. The magnetic field may be coaxial to the cylinders, or at an angle thereto so that some electrons pass through the grids without striking them. The cathode 1 may be thermionic or photo-electric. The battery B<3> is connected to the tuned circuit at potential nodes or through chokes. In an amplifier, the control signals are applied to the magnetic field or to one grid such as 2 or between two grids and the output is taken from across two electrodes such as 4, 5. Specification 185,752, [Class 39 (i)], is referred to. The Specification as open to inspection under Sect. 91 comprises also drawings of a circuit for a reaction oscillator and of an amplifier with photo-electric cathode illuminated according to the input signals. This subject-matter does not appear in the Specification as accepted.