US2921225A - Traveling wave tube - Google Patents

Description

Jan. 12, 1960 KLElN ETAL 2,921,225

TRAVELING WAVE TUBE Filed Sept. 2, 1955 IN VEN TORS. WERNER KL 'lN WAL TEE Ffl/Z A 7' TGRNE Y United titates Patent TRAVELING WAVE TUBE Werner Klein, Korntal, Wnrttemberg, and Walter Friz, Stuttgart, Germany, assignors to C. Lorenz Alrtienge sellschatt, Stuttgart-Zulienhausen, Germany, a torperation of Germany Application September 2, 1955, erial No. 532,322

Claims priority, application Germany September 3, 1954 5 Claims. (Cl. 3153.6)

In our copending application Serial No. 499,163 filed April 4, 1955, now Patent No. 2,857,547 issued Oct. 21,

1958, a tube structure is shown wherein a connecting pipe between pairs of cylinders at the input and the output ends of the tube serves mechanical as well as highfrequency purposes, particularly the suppression of unwanted high-frequency feedback. The exclusion of feedback paths is achieved by suitably dimensioning the pipe, as stated in the main patent, and by attaching a damping layer to the dielectric pipe. When such a tube is provided with a plurality of galvanically separated helices then a corresponding number of lead-in conductors will become necessary for the individual helices. In most of such cases, and in order to obtain a suitable structural shape of the tube, these lead-in conductors will be led through the wall of the vacuum container of an existing socket. These metallic lead-in conductors would then proceed along the helices and would inherently act as a feedback circuit.

In accordance with the invention it is therefore suggested to employ the damping layer or coating of the dielectric pipe as the helix connecting line for the added helix. It is also possible, by longitudinally dividing the damping layer into galvanically separated paths, to connect a plurality of helices or cavities lying along the length of this helical arrangement or to connect conductive layers attached to the insulating body surrounding the electron beam for the purpose of avoiding any charging phenomenae, or to connect a modulating cylinder, with a terminal of the socket connections. Since the charging rate of the helices or of the other mentioned electrodes respectively, is small in any case, the somewhat increased lead-in resistance of the damping layer will not be detrimental. Accordingly, the special lead-in conductors with their unwanted feedback effects, will also be done away with.

The invention will now be particularly described with reference to an exemplified embodiment.

The accompanying drawing shows the helix zone of a traveling wave tube employing e.g. two separated helices 1 and 2. These helices are held in position by the ceramic bars 3. Helix 1 is in metallic connection with the pair of cylinders 4, 5 and helix 2 with the pair of cylinders 6, 7 by means of the antennas 8 and 9 respectively. The ceramic bars 3 are received and supported by apertures provided in the bottoms of the cylinders 4 and 7. The dielectric pipe 10, that is provided with ICC a damping layer 11, forms the mechanically rigid connection between the two pairs of cylinders 4, 5 and 6, '7. The damping layer 11 also extends over the mechanical joint between pipe 10 and cylinder 6, but is separated from the cylinder 5 by a ring-shaped uncoated portion of the pipe. The helix 2 is connected via the antenna 9, the cylinder 6, the flange ring 12, th damping layer 11, the clip 17, and the connecting wire 15 which is led through the little insulating tube 14 arranged in the profiled component 13. The helix 1 is connected to the connecting line 16 by the antenna 8 via the cylinder 5, the profiled component 13 and the cylinder 4.

Of course, a damping layer applied to the inside of the dielectric pipe may take over the function of further connecting lines.

What is claimed is:

1. A traveling wave tube comprising two coaxial successive helical delay lines insulated from one another, a tube of dielectric material supported in coaxial spaced relation with said helices and extending therealong substantially to the opposite ends thereof, a socket terminal at one end of said tube having a plurality of terminal pins, a conductive attenuating coating on the dielectric tube insulated from the helix at the socket end of said tube and conductively connected to the other helix, said coating being in the form of galvanically separated tracks, whereby several independent terminal connections may be made, a connection from one of said terminal pins to the helix near said socket end, and a conductive connection from another terminal pin to said conductive coating, whereby independent operating voltages may be applied to said helices.

2. A traveling wave tube as claimed in claim 1, characterized in that one said track of the damping layer serves as the connecting line for a modulating electrode.

3. A traveling wave tube as claimed in claim 1, characterized in that with traveling wave tubes employing n helices at least nl tracks of the damping layer serve as connecting lines for n1 helices.

4. A traveling wave tube as claimed in claim 1, characterized in that at least one track of the damping layer serves as the connecting line for a cavity arranged in the course of the helix arrangement.

5. A traveling wave tube as claimed in claim 1, characterized in that at least one track serves as connecting line to an arrangement serving to avoid any charging phenomena.

References Cited in the file of this patent UNITED STATES PATENTS 2,487,332 Hagen Nov. 8, 1949 2,585,582 Pierce Feb. 12, 1952 2,602,148 Pierce July 1, 1952 2,660,689 Touraton et a1. Nov. 24, 1953 2,766,398 Orthuber Oct. 9, 1956 2,806,177 Haeff Sept. 10, 1957 2,806,974 Haefl Sept. 17, 1957 2,841,739 Pierce July 1, 1958 FOREIGN PATENTS 668,725 Great Britain Mar. 19, 1952

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