DE1060924B - Modulation device for very short electromagnetic waves - Google Patents

Description

The invention relates to modulation devices of the type in which gyromagnetic Material is arranged in the longitudinal direction of a waveguide and in which the modulation a wave propagating in the hollow line is made by that component of the magnetic flux in the material, which in the direction of corrugation propagation along the waveguide is changed.

The mode of operation of a device of this type can generally be based on expressions or data the Faraday effect will be explained. Often a material of the ferrite genus is called gyromagnetic.es Material used; hence the term ferrite modulator, which is generally used.

Ferrite materials are known which have a small loss at microwave frequencies, and accordingly modulating devices using these materials can be made or arranged to ^{operate at these 1} frequencies.

However, difficulties arise in the practical implementation or manufacture of such devices which mainly relate to the switching or control means or are caused by them, which for the Changing the magnetic flux in a modulation device as a function of a given modulation signal are provided.

A method of transmitting a modulation signal by changing the magnetic flux consists in that a magnetizing winding is arranged around the shaft guide. In In this case, eddy currents are caused by the modulation field or by the modulating magnetic field induced in the walls of the waveguide, and these set a limit on the modulation frequency. at another method in which the electromagnet is wound on the inside of the wave guide a problem arises because the coil of the electromagnet is in the wave propagation path is located.

The purpose of the invention is to provide an improved modulation device of the aforesaid Genus.

According to the invention of the aforementioned type is defined by the wall of the wave guide, a current path for a modulation signal, or set in a modulation apparatus, approximately extends which is m-way direction about the axis of wave propagation of the wave guide and along the longitudinal direction thereof.

The invention will now be explained in more detail with reference to the drawing showing it for example be, namely shows

Modulation facility
for very short electromagnetic waves

Applicant:

National Research Development
Corporation
London

Representative: Dipl.-Ing. Ε. Schubert, patent attorney,
Siegen (Westphalia), Oranienstr. 14th

Claimed priority;
Great Britain March 15, 1957

Arthur Langley Morris, Malvern, Worcestershire
(Great Britain),
has been named as the inventor

1 shows a partially sectioned view of an embodiment of a ferrite modulator, while

• Fig. 2 shows a further embodiment of a ferrite modulator.

As can be seen from FIG. 1 , a thin, electrically conductive, circular tube 1 has a narrow spiral-shaped slot 2 which runs in the direction of the tube 1. The tube 1 is through a. Body or a shell 3 held from plastic material, which or which usually consists of an epoxy resin, for example such a resin that is known under the registered trademark "Araldite". The shell3 is transparent; therefore, it is possible in the drawing to visibly indicate pipe 1 through sheath 3. At the left end of the tube 1 is, as can be seen from the drawing, an end flange 4, which is in electrically conductive connection with the tube, with the exception of where a short longitudinal slot 5 is the continuation of the spiral slot 2 from the end of its spiral path to Forms the end of the tube 1. At the other end of the tube 1 a second end flange 6 is fastened in a similar manner, but with the difference that it does not make a conductive connection to the end of the tube 1. Eiin connection 7 is attached to the Kunststoffhüllc 3 and connected via a wire 8, which runs in the shell 3, to the end of the spiral, which the tube 1 now-

909 560/297

more "as a result of the slot Z-.. The end of the .diameter of the spiral-forming tube entSchlitzes 2 is used up to the end of the tube 1 via a - -'-. A further short spiral slot is continued in the mandrel or continuous track, groove or recess and set at each; in the drawing this is concealed by the end tracks, grooves or recesses for the flange 6. - - 5 Lang ⁱ Sadern-Cin-cut or worked into and with

A rod 9 made of ferrite material, for example filled with an insulating plastic filler,

a.Magnesium-Manganese-Ferrite, by means of, for example, an epoxy resin such as Araldite

tubular foam spacer component 10, the tracks or grooves relative to the surface again

arranged axially to the tube 1. to compensate or to make flush. Then it will be

In operation, the device according to FIG. 1 is applied with the aid of 10 a copper layer on the drawing mandrel in a galvanized flange 4 and 6 at its ends in any niche bath. The copper is not inserted into the waveguide transmission system; suitable over the plastic-filled track or from circular farm-rectangle transition links - are provided, if savings are deposited, and the required pipe is required, and a source for a is thus with a spiral-shaped slot, which high-frequency modulation signal is at terminal 7 15 - extends along its length, provided,
connected to one pole, with the other. After electroplating, a coating or pole is grounded

A modulation signal current flows along which is still located on the mandrel, plotted; the tube spiral of the tube 1 from the connection 7 to the end is then removed from the mandrel ·, and the end flange 4; the end flange 4 is grounded; the flange 6 20 flanges are attached.

however, albeit with the shaft guiding system, the cross-section of the slot, which is connected because of the, is isolated from the pipe 1 and forms bill- - spiral groove, diminishes to the extent that det no part of the modulation signal circuit. the wall thickness of the copper increases; Even if the The modulation signal current thus flows in a spiral slot in each case narrow or tightly made around the ferrite rod 9, and the magnetic flux in the 25 , it becomes even narrower in the galvanic manufacture of ferrite rod 9 according to the around processing method. Albeit self-evident flowing modulation signal stream. Care must be taken that the

It follows that the propagation of a slot is not bridged, so the wave in the circular tube 1 in accordance with the gap of the slot on the surface of the copper with the modulation signal, which the terminal 7 30 can be made so narrow that during operation which is supplied, is controlled, and the wave is only slightly microwave-efficiently modulated in the modulator. radiation exits through the slot.

In the design of the device shown in Fig. 1 As an alternative method, the use of the slot 2 is narrow or narrow made to da.- printed switching arrangements or techniques for the manufacture of the pipe by radiation from the interior of the pipe 1 35 1 proposed,
outwards to a minimum. Another modulator embodiment is to be added. The wall thickness of the tube 1 is small; it illustrates Fig. 2, in which two circular must be chosen so thick that the tubes IA ₁ IB each have a spiral slot waves along the waveguide system, of which 2 A ₁ 2B ; the spiral slots 2A ₁ forming a part of the tube can propagate; 40 25 are arranged in such a way that they run around the axis on the other hand, the wall thickness must be as small as possible, the tubes 1 A ₁ IB ₁ and in opposite directions, wrapped around the eddy current losses in the tube, run. Add the pipes 1 A ₁ IB . collide at a common edge 12,

The number of turns of the spiral, which they are there isolated from each other. The two

is formed by the slot 2 in the tube 1, with 45 tubes IA ₁ IB are with their end flanges AA ₁ 4 B

Consideration of the modulation signal frequency and which in turn is inserted into a waveguide system.

Frequency of the wave chosen, which is in the pipe 1 The flanges AA ₁ AB stand with their respective

propagates, with the level of the modulation current, tubes IA ₁ IB in electrical connection and

which flows during the operation of the device also provide an earth connection, since it is connected to the pipes 11

if must be taken into account. 50 of the wave guide system are connected.

In a typical practical example, the circular tube 1, as in the modulator shown in FIG. 1, had a diameter of 0.9 inches, the tubes 1 A ₁ IB rest in an epoxy (22.9 mm) envelope; the overall length of the loading Rohrabschndtts resin 3. The tubes l. <4, IB enclose similarly carried 5.5 inches (139 mm ^ 7), and it had fourteen angular manner a tubular Sehaumstoff-Abstandsbaudungen with a pitch of three turns 55 parts each and a rod of ferrite material - which is inches (1.18 turns / cm) on. The diameter of the two extend between the flanges 4 A ₁ AB. A magnesium-manganese ferrite rod was 0.25 inches. Terminal 7 is held in resin sheath 3. He is (6.35mm). A wave with a frequency of connected to the abutting edge 12 of the pipes IA ₁ IB . 9375 megahertz, which is propagated along the pipe 1 in operation is a source of a high frequency, was then modulated when a current 60 modulation signal M with one pole at terminal 7 of 1 ampere with 7 megahertz connected to terminal 7 and with the other Pole grounded. The tube 1 was fed. The passage pipes 11 of the path guidance system deliver 0.5 decibels through the damping. Tubes IA ₁ IB microwave energy; thus becomes a

For the production of the pipe 1 circuit is preferably closed from the grounded pole of the source

that of E.B. Cowley and G.W. Fynn developed 65 of the modulation signal over the link

Method used which in the pending bni- terminal 7 and over the oppositely wound

table patent application 8593/57 is treated. Spirals, which are on the tubes IA ₁ IB ,

In short, this procedure uses a mandrel after the grounded flanges AA ₁ AB. This will

stainless steel of a length and one causes the microwave energy in the wave guide

Outer diameter, which corresponds to the length and the inner 7 ° system through the supplied by the supply source M

Claims (8)

delivered signal becomes moduHert. This construction has the advantage that the flanges can be kept at ground potential and that there is no complete annular interruption in the shaft guide system. Only one supply, namely the connection 7, is required for the two tubes 1 A, IB, and no flanges are required where the two meet. This simplifies the electrical circuit arrangement of the modulator. In addition, it is proposed for the manufacture of the modulator to manufacture the Rohrelyij IB in one operating process, i. H. by electroplating on a single mandrel. If it is desired to reduce the radiation through the spiral-shaped slot of a modulator, or if one wishes to reduce the thickness of the ferrite rod 9 in order to prevent heating of the same, a tube made of a material with a high dielectric constant can be used instead of the tube shaped Foam spacer 10 of Fig. 1 may be used. Suitable materials are polystyrene and polytetrafluoroethylene (P.T.F.E.). Boron nitrides are also suitable; because of their greater conductivity, they provide an additional advantage. It is proposed to expand the embodiment arrangement so that increased cooling takes place in that a liquid dielectric is used on SteMe of the dielectric tube; dielectric partitions must be provided in the hollow pipeline to support the ferrite rod. In the case of high-performance modulators, it may be desirable to provide a certain amount of cooling, if this is possible or permissible, and for this purpose it is proposed to create a means for cooling the modulator by using a silicone oil or possibly a carbon tetrachloride as the liquid dielectric. Suitable circuit and cooling arrangements can be provided for the cooling liquid. For example, a cooling radiator can be connected to the modulator by means of appropriate lines and small holes in the wall of the wave guide. Claims: 45 1. Modulation device for very short electromagnetic waves, in which gyromagnetiscbes Material is arranged in a waveguide and in which the modulation of a iim Waveguide propagating wave is made that in the gyromagnetic material that component of the magnetic flux, which in the direction of the wave propagation in the waveguide runs, is changed, characterized in that the current path in the wall of the waveguide for the modulation signal is set so that this current is both around the axis of the waveguide around as well as in the longitudinal direction thereof. 2. Wave modulation device according to claim 1, characterized in that the length the shaft guide is limited by end flanges, and that one flange in electrical Is connected to the wall of the wave guide and forms one end of the current path, while the second flange is isolated from the wall of the wave guide, and that a connection after the wall of the waveguide, which lies in the vicinity of the second flange to thereby form the other end of the current path for the modulation signal. 3. Wave modulation device according to claim 1, characterized in that in the Wall of the waveguide a second current path for the modulation signal is established, which from a point that it has in common with the first current path into the opposite one Direction around the axis of the waveguide and in the opposite direction along its longitudinal direction extends. 4. Wellenmodulationseinricbtung according to claim 3, wherein the length of the waveguide is limited by end flanges, characterized in that the flanges are in electrical communication stand to the wall of the river guide to thereby form the ends of the river paths, which - are on opposite sides and far from the common point, and that one Connection at the common point is established, which means when operating when the modulator is connected to its flanges in an associated waveguide system, the two current paths from a modulation current supply source, which is placed between the grounded waveguide system and the connection is switched at the common point, fed in parallel. 5. wave modulation device according to claim 1, 2, 3, 4, characterized in that the or the flow paths are formed by a spiral slot or slots which run over the wave guide wall and on the inside of the wave guide wall are wider than on the outside. 6. wave demodulation device according to claim 5, wherein the gyromagnetic material is in the form of a rod, characterized in that a layer of insulating material is applied to the outside of the slotted wave guide, thereby to hold the wave guide that the rod of a liquid dielectric material is surrounded and that means for cooling and Ιη ^ εΐΒ ^ ΛΓΗ ^ εη 'of the liquid material are provided. 7. Wellenmodulationseinrichtuing according to claim 5, wherein the gyromagnetic material is in the form of a rod, characterized in that the rod has a sleeve made of dielectric Material wears. 8. wave modulation device according to claim 7, characterized in that the dielectric Material is boron nitride. 1 sheet of drawings © 903 560/297 6.