Patent GB-516750-A (GB)
Title: Electron oscillators for generating electromagnetic waves of ultra-high frequencies
IPC: H03B9/01
Filed: 1938-07-08
Abstract: 516,750. Electron oscillators. STANDARD TELEPHONES & CABLES, Ltd. July 8, 1938, No. 20285. Convention date, July 31, 1937. Classes 39 (i) and 40 (v)] In an electron oscillator for generating waves of ultra-high frequency a hollow resonator is used with fixed conductive parts resonating at the desired frequency and of such dimensions that the time of flight of electrons across or through the resonator exceeds by one-quarter cycle the cycle time of the generated frequency or a multiple thereof. An indirectly heated cathode C is mounted directly opposite the anode A being carried by insulation 7; the upper plate could be the cathode being sensitized only on the surface opposite the plate C. A source 10 supplies the potential to the anode ; a signal may be introduced in the lead to the anode by including the secondary of a signal transformer in this lead, thereby obtaining amplitude modulation. Cooling water may be circulated in the chamber 18 ; the conductor 2 carrying the cathode C has a sleeve extension 28 surrounding the heater leads 4, 5. In a modification the conductor 2 is of annular form carrying a cathode surface on both faces which co-act with upper and lower anodes on an enclosing shell. In a further form the insulation between the anode A, Fig. 6, and cathode C is obtained by a gap 7 corresponding to the gap formed by the insulation 7 in Fig. 4 ; the extension 55 forming. the cathode support is of half wave length, but this extension may be omitted. In cylindrical diode form the cathode may be the inner cylinder or the outer C, Fig. 7, the cathode heater being enclosed by a shield F ; in addition to radiation, heating by bombardment by emission from the heater filament is used. The anode may be water-cooled. The diode electrodes constituted in part by the anode and cathode form a half wave line. In a modified form of oscillator a beam or beams of electrons traverse the resonator. A beam concentrated by one or more electrodes 36, Fig. 10, passes through orifices 33 in the resonator 31 the transit time across which is 5, 9 &c. quarter cycles ; a collector anode 34 receives the beam beyond the resonator. In a modification of this a central filament F, Fig. 12, radiates four beams-concentrated by electrodes 36-through corresponding orifices 33 in the resonator 39, 40. In a modification of this construction the orifices 33, Fig. 14, are formed in the parallel walls of segments 44 emitting filaments F with electrodes 36 being in one quarter and receiving anode 34 in another. Biasses for the electrodes 31, 34 and 36 are provided by sources 32, 35, 37. Oscillators as described above may be coupled with wave guides having a tuning partition 25a, Fig. 8; a narrow air gap separates the anode A from the inner line conductor 22. A glass section 25 separates the anode and cathode. In another form a wave guide 27, Fig. 9, is connected to the anode through the cone 28 and extension 28a and the cathode is connected to a coaxial rod 29a. The guide 41, Fig. 14, is closed at one end by the adjustable solid disc 42 and at the other by a movable iris diaphragm 43. Specification 499,681 is referred to.