GB590471A - High frequency electron discharge devices - Google Patents

Abstract

590,471. High-frequency discharge apparatus. STANDARD TELEPHONES & CABLES, Ltd. June 9, 1944, No. 11124. Convention date, Dec. 15, 1942. [Class 39 (i)] An electron discharge device for use at high frequencies comprises two parallel, preferably circular, metal plates 10, 12, Fig. 1, which are held in spaced relation by quartz insulators 14 and provided at their peripheries with annular electrodes 16, 20, and a glass envelope 30 -sealed to the plates and enclosing the electrodes, the plates and electrodes forming the walls of a hollow resonator. The metal ring 16 forms the anode and a grid 20 may be mounted on a similar ring 18. The cathode 22 is indirectly heated and is provided with an extension 26 which is coupled capacitatively to a disc 28. The plate 12 and disc 28 are provided with downwardly extending rims 36, 38 respectively which are slidably engaged by a toroidal cup 40, thus forming an external tunable grid-cathode resonator. The internal resonator may be tuned by a screw 46 which actuates a flexible diaphragm 42. Energy is extracted and communicated to a transmission line or wave guide 60 by a rod 48 passing through the plate 10, the rod being preferably adjustable to vary the coupling. For this purpose, the plate 10 is provided with a threaded bushing 50 supporting a threaded collar 52, which slides in an annular groove formed in the extension 53 of a flexible bellows 56. In a modification, Fig. 3 (not shown), the electrode surfaces are mounted parallel with the plates 10, 12, instead of at right angles thereto. The arrangement may be used as a diode, in which case the cathode 22 is dispensed with, one of the members 16, 18 serving as the cathode and the other as the anode.