GB849867A - Improvements in or relating to high-frequency electron valves - Google Patents

Abstract

849,867. Thermionic-cathode tubes. SIEMENS & HALSKE A.G. Oct. 14, 1958 [Oct. 18, 1957], No. 32762/58. Class 39(1). A cathode 1a 1b is in the form of a hollow cylinder emitting electrons radially inwards and outwards ; control electrode 2a and anode 4a surround the cathode concentrically, and concentrically within it lie a further control electrode 2b and anode 4b, the two anodes being integral or electrically connected, and having, extending between them insulating material 7 in which the control electrodes and cathode are supported. In the form shown, the anodes are part of an integral channel-section structure forming the tube envelope. A screen grid structure, similarly disposed on both sides of the cathode, may be incorporated. The cathode has a centre-tap lead 1d. The inner and outer sections of the cathode, of the control grid, and of the screen grid, may be integral, or mechanically separate, or even electrically separate in which case the grid sections may have different characteristics. Some of these electrodes may be replaced by dummies. The electrodes are supported by extensions which pass through an insulating closure 7 as concentric rings. Outwardly of the envelope these form a series of concentric resonant cavities, which can be tuned by movable slides 5. These slides may all be actuated simultaneously.