US1938065A - Microray vacuum tube - Google Patents

Description

Dec. 5, 1933. A. G. CLAVIER 1,933,065 I MICRORAY VACUUM TUBE Filed Dec. 19. 1931 l4 I I M I I I I L" 17 I3 WI I L' :5

I II 'IIl6 INVENTOR ANDRE c. CLAVIER Patented Dec. 5, 1933 1,938,065 MICRORAY VACUUM TUBE Andr G. Clavier, Glen Ridge, N. J., assignor to International Communications Laboratories, ,Inc., Newark, N. J., a corporation of New York Application December 19, 1931 I Serial No. 582,091

4Claims.

This invention relates to micro-ray vacuum tubes and circuits, and particularly to a micro-ray vacuum tube with a two-terminal helicoidal reflecting electrode.

The term micro-ray tube or "micro-ray vacuum tube" is to be understood as meaning a tube for operating with frequencies lying within the approximate range between 100 centimeters and 1 centimeter.

In my U. s. Letters Patent No. 1,928,408, I have disclosed a method of and apparatus for producing and detecting micro-rays, that is, rays lying roughly in the range between 100 centimeters and 1 centimeter. In the system disclosed in that application there is a micro-ray tube having a straight wire filament or cathode, a helical oscillating electrode or grid, with its axis along the filament, and a cylindrical reflecting electrode or anode concentric with the oscillating electrode. In a tube constructed in that manner, the dissipation of power in the reflecting electrode is rather high, in a particular'case being about 20 watts. Also in that system there is a tendency for oscillations to be generated in the reflecting electrode, with a lessened eficiency in the operation of the tube.

The object of this invention is to improve the operating characteristics of a micro-ray vacuum tube.

A feature of the invention is a reflecting electrode which is helical.

Another feature of the invention is the provision of means for tuning the reflecting electrode circuit or, alternatively, for preventing oscillations on the reflecting electrode.

In the drawing,

Fig. 1 is a diagrammatic sketch, partly in section, of a micro-ray tube according to this invention; and Fig. 2 is a schematic circuit diagram of a microray tube and associated circuit, and means for tuning the reflecting electrode circuit or, alternatively, for preventing oscillations on the reflecting electrode.

In Fig. 1 a highly evacuated chamber 1" has therein a filament or cathode 2, a helical grid or oscillating electrode 3,"'and a reflecting electrode 4, in accordance with previous practice. These elements are mounted upon a stem 5 and insulating members 6, '1. Leads 8 and 9 are connected to the oscillatingtelectrode and leads 10 and 11 are connected to the reflecting electrode. The reflecting electrode, instead of having a'solid surface as in previous micro-ray tubes, is a helix. Also the reflecting electrode, instead of having a single lead as in previous practice, has two leads 10, 11, one connected at eachend of the electrode and leading from the tube in the opposite direction from the leads '8, 9 from the oscillating electrode. This construction of the reflecting electrode, that is, helical instead of with a solid surface, permits the oscillating electrode to operate at a lower temperature, which increases the emciency of the tube.

In Fig. 2- the tube 1 is shown with elements and leads numbered similarly as in Fig. 1. Leads 8 and'9 are connected to aradiating or receiving doublet\DD1. A lead 12, connected to the center point of the doublet, is connected to a battery 13 which supplies a positive potential for the oscillating electrode 3. A battery 14 supplies current for the filament 2 and a battery 15 supplies potential to the reflecting electrode 4 across potentiometer 16, which is provided to permit this electrode to be properly biased. Leads 10 and 11 from the ends of the reflecting electrode are parallel to one another and pass through holes in a reflecting screen 17, with suitable insulation between the leads and the screen. The screen 17 may be made of any suitable reflecting material,

OFFICE such as aluminium, brass or copper, with its refleeting surface toward the tube 1. After passing through the screen the leads 10 and 11 may be joined and connected to a tap on the potentiometer 16. The screen 17 should have a large surface relative to the wavelength at which the system is operating, that is, its surface in each direction should be two or three time's the wavelength- The distance of the screen from the tube may be adjusted so that the circuit of the reflecting electrode is tuned or it may be adjusted so that there are no oscillations in this circuit. The distance of the screen from the tube for thesev two adjustments mentioned may be determined in each case by experiment. A means is thus provided for controlling the efficiency of the tube, increasing it for transmission purposes, reducingthe tendency to self-oscillations when the tube is used as a detector.

The circuit and reflecting screen 17 may be used with the previous types of micro-ray tubes, as well as with the improved tube disclosed herein.

What is claimed is:- r

1. A micro-ray tube, a reflecting electrode therein, two leads connected to said reflecting electrode, a reflector, and apertures in said reflector through which said leads pass.

2. A micro-ray tube, a reflecting electrode 7' therein, a circuit connected to opposite ends of oscillating and a reflecting electrode therein, a 5 radiating doublet, leads connecting the terminals 01 the oscillating electrode, leads connected to the terminals of the reflecting electrode, and means including a reflector, through which the reflecting electrode leads extend, to tune the circuit including the reflecting electrode and its leads to the frequency radiated by the doublet.

4. The combination according to claim 3 characterized in this that the reflecting electrode is composed of a conductor arranged in a coil'so as to form a cylinder whereby said electrode forms an essential part of the inductance of its tuned circuit.

ANDRE G. CLAVIER.

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