DE1113272B - Decoupling device for an electric discharge tube for very short waves - Google Patents

Description

GERMAN

PATENT OFFICE

kl. 21g 13/17

INTERNATIONAL KL.

HOIj; H 03 b

S 54503 Vma / 21g

REGISTRATION DATE: JULY 26, 1957

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL: AUGUST 31, 1961

The invention relates to electrical discharge tubes for very short waves, in particular reflex klystrons, and in particular decoupling devices for such tubes.

At low microwave frequencies, one can use the microwave energy normally generated in an evacuated cavity resonator of a klystron for utilization via a coaxial line lead to the load. The coaxial lines are in theirs mechanical structure simple and can be vacuum-tight to the simple and cheap process Resonator to be attached.

At higher microwave frequencies, the microwave energy from the cavity resonator must be means can be taken from a waveguide. Because of the relatively large cross-sectional area and the The rigidity of the waveguide arrangement was the previously known klystrons with outcoupling waveguide arrangements complicated in their mechanical structure and expensive to manufacture.

It is known, in the case of a klystron, to connect the cavity resonator directly to the output waveguide through an opening to pair. This type of coupling is extreme in terms of its transmission properties unsatisfactory.

There is also a type of decoupling known in klystrons, according to which the cavity resonator via a coaxial line section is coupled to the waveguide. However, the wave resistance must be the coaxial line to be matched to that of the waveguide, which leads to the manufacturing technology mentioned Difficulty leads.

Finally, a klystron type is known in which a coaxially surrounds the cavity resonator and a chamber communicating with it is provided, but as a kind of short-circuiting Throttle is formed. To achieve a soaking broadband quality of the coupling arrangement a special one must be used here for coupling the output waveguide to the cavity resonator Transformers are provided.

. The invention now relates to an electric discharge tube for very short waves, in particular Reflex klystron, with a substantially metallic vacuum housing, at least one inside the housing arranged, provided with central openings for the passage of the electron beam rotationally symmetrical cavity resonator and a coupling device for decoupling the Radio frequency energy from the cavity resonator consisting of one inside the housing coaxially arranged to the cavity resonator, with the decoupling device

for an electric discharge tube

for very short waves

Applicant:

Sperry Rand Corporation,
Great Neck, NY (V. St. A.)

Representative: Dipl.-Ing. C. Wallach, patent attorney,
Munich 2, Kaufingerstr. 8th

Claimed priority:
V. St. v. America August 1, 1956

Gisli Conrad Dalman, Ithaca, NY (V. St. Α.),
has been named as the inventor

Cavity resonator coupled rotationally symmetrical chamber (coupling chamber), which in part is formed by the inner surface of part of the housing, and one perpendicular to the axis of the Coupling chamber extending, coupled to the coupling chamber waveguide piece for discharge of high frequency energy.

Such an electrical discharge tube is formed according to the invention so that the coupling chamber is designed and dimensioned such that its resonance frequency is above the highest Frequency is the operating frequency range of the tube.

Through this training, the disadvantages and difficulties mentioned, as they are in the known arrangements result, avoided. The structure is significantly simplified because the waveguide can be coupled directly to the coupling chamber without any difficulties in terms of the adjustment of the wave resistance occur.

In other words: Since the coupling chamber is not in Resonance, their dimensions are not critical, so that precision machining is not required is. In particular, the waveguide can, even with large dimensions, directly on the housing of the arrangement be attached. Together with the known feature, according to which part of the coupling

109 680/195

Chamber is formed by the inner wall of a part of the housing, this results in the other Advantage that the discharge tube with the coupling device as a whole are made very solid can.

According to a preferred embodiment, the coupling chamber is in the form of one that is short-circuited on both sides Coaxial line formed, the length of which is less than half the wavelength of the highest Frequency of the operating frequency range. According to a further advantageous embodiment, can the cylindrical inner wall of the coupling chamber also serves as an electrode holder.

Another embodiment of the invention is that the electrode holder for tuning of the cavity resonator arranged to be movable in the axial direction and on two in the axial direction distant points via flexible membranes, the distance between which is the length of the coupling chamber determined, conductively connected to the housing.

Further advantages and details of the invention emerge from the following description of a Embodiment based on the drawing. In this shows

1 shows a longitudinal section through a reflex klystron according to the invention,

FIG. 2 shows a section along the line 2-2 according to FIG. 1,

3 shows a section along the line 3-3 according to FIG. 1,

4 shows a perspective view of the individual parts of interest in the present context of the Refiexklystron according to Fig. 1 in an exploded view.

The reflex klystron of Fig. 1 consists of five main parts, namely the lower housing part 11, the cathode assembly 20, 23 and 24, the upper housing part 40, the reflector 52 and the tuning device 57, 58. The cylindrical housing consisting of the two parts 11 and 40 is as a whole denoted by 10.

The cold-drawn steel cylinder 11 forming the lower housing part is at its end face 13 with a Provided indentation which has an outer annular side wall 14 and an annular Base 15 forms with a conically re-entrant perforated part 16, the opening of which with a Mesh 17 is provided.

The cathode arrangement has a cathode cup 20 with a heating coil 24 and a focusing electrode 23 and is mounted in a cylindrical part 31 which is provided with axially parallel slots 33 is so that it can be pushed onto the outer periphery of the side wall 14, whereby the Electron beam source 20 can be aimed at the opening of the re-entrant 16.

The steel cylinder 40 forming the upper housing part has a lower one that is drawn inwards Flange 41 is welded vacuum-tight to the end wall 13 of the lower housing part 11. The upper Flange 42 of the upper housing part carries the tuning device.

The reflector electrode 52 surrounds a nozzle 48, which at its lower end 49 on the one hand with the inner edge of an annular flexible membrane 50 and on the other hand with the opening of the Membrane-covering mesh screen 51 is welded. The connector 48 carries in its interior the reflector electrode 52.

The membrane 50, the side wall 14 and the bottom surface 15 form with the re-entrant part 16 and the mesh grids 17 and 51 the cavity resonator 61. The outer edge of the membrane 50 is welded to the end wall 13.

A flexible vacuum-tight membrane 63 is on its inner circumference on the nozzle 48 and on its

ίο Soldered the outer circumference to the membrane retaining ring 46. The tuning device has a screw 66, which on the one hand with the internal thread of the Tuning cap 68 and on the other hand cooperates with the inner screw 57, which with the Nozzle 48 is connected.

The wave guide intended to carry the generated electromagnetic energy to the load (Waveguide) is shown at 44; it has a flange 45 at its outer end, in which a window 70 made of mica is inserted in a vacuum-tight manner.

According to the invention, the generated microwave energy passes from the cavity resonator 61 a coupling chamber 80 into the shaft guide 44, from where it is continued to the load. The coupling chamber 80 is of the membranes 63 and 50, the nozzle 48, a part of the upper Housing part 40 and limited by its end wall 13 and corresponds to the shape of the section a coaxial line. With the wave guide 44, the coupling chamber 80 is above a rectangular one Output opening 43 in the cylindrical jacket of the upper housing part 40 in connection, with the cavity resonator 61 through an opening 78 of preferably crescent shape in the Membrane 50 (cf. in particular FIGS. 2 and 4 in this regard).

According to the invention, the substantially by the distance between the two membranes 63 and 50 determined the electrical length of the coaxial line section forming the coupling chamber 80 as follows chosen to be less than half a wavelength of the highest frequency of the operating frequency range the tube will. This prevents the coupling chamber from acting as a low-quality resonator and the output power decreases.

The decoupling device described is simple and robust and particularly suitable for use at higher microwave frequencies.

Claims (4)

PATENT CLAIMS: 1. Electric discharge tube for very short waves, especially reflex klystron, with a essentially metallic vacuum housing, at least one arranged inside the housing, rotationally symmetrical ones with central openings for the passage of the electron beam Cavity resonator and a coupling device for decoupling the high-frequency energy from the cavity resonator, consisting of one arranged inside the housing coaxially to the cavity resonator, rotationally symmetrical chamber (coupling chamber) coupled to the cavity resonator, which is formed in part by the inner surface of part of the housing, and one perpendicular to the Axis of the coupling chamber extending, coupled to the coupling chamber hollow Conductor piece for dissipating the high-frequency energy, characterized in that the coupling chamber (80) is designed and dimensioned in such a way that its resonance frequency is above the highest frequency of the operating frequency range of the tube. 2. Electrical discharge tube according to claim 1, characterized in that the coupling chamber (80) in the form of a coaxial line (40, 48) short-circuited on both sides whose length is less than half the wavelength of the highest frequency of the operating frequency range. 3. Electrical discharge tube according to claim 2, characterized in that the cylindrical Inner wall (48) of the coupling chamber (80) also serves as an electrode holder. 4. Electrical discharge tube according to claim 3, characterized in that the electrode holder (48) for tuning the cavity resonator (61) arranged to be movable in the axial direction and on two in the axial direction from one another distant points via flexible membranes (63.50), the distance between which is the length of the Coupling chamber determined, conductively connected to the housing (10). Considered publications: French Patent No. 1097 861;
British Patent Nos. 729 812, 744 262;
"The Bell System Technical Journal", 1955,
P. 563 ff .; Electronics, April 1952, p. 115. 1 sheet of drawings © 109 680/195 8.61