DE1038138B - Arrangement with a Lecher line, in particular a ribbon line, as a one-way line - Google Patents

Description

GERMAN

The invention relates to an arrangement with a waveguide as a one-way line for microwaves on a gyromagnetic basis, namely on an arrangement with such a waveguide in which the electromagnetic energy propagates in the form of Lech waves.

One-way lines are known from waveguide technology. There is a suitable one in a waveguide dimensioned body made of ferromagnetic material arranged. If now one for the magnetic Saturation of the material mentioned, a sufficiently strong magnetic field is applied, then one of the a direction incident wave of a certain frequency without significant attenuation of the waveguide while a wave of the same frequency incident from the opposite direction is strong is dampened. The cut-off frequency at which this phenomenon occurs is determined by the gyromagnetic Resonance in the ferromagnetic material is determined, and the gyromagnetic resonance is from depends on the magnetization of the material and thus on the strength of the magnetic field.

This directional locking effect owes such a one-way line to the fact that its Mode of action is based on a property of the electromagnetic field that depends on the direction of transmission is dependent. It is the state of circular polarization of the magnetic field vector, which, if it is given in a pure form in one area, is theoretically perfect and directional Locking effect.

However, the circularly polarized magnetic field vector is in the waveguides in which the Propagates energy in the form of Lech waves, e.g. B. ribbon cable or coaxial cable, not given, so that the blocking effect described above does not come about easily with these waveguides.

It is already a high frequency directional coupler on a gyromagnetic basis for ribbon cables known, in which the necessary circularly polarized magnetic field is generated in that the line conductor of the incoming ribbon cable spirally on one end face of a cylindrical Ferrite body and the line conductor of the outgoing ribbon cable for the purpose of reconversion into a linearly polarized magnetic field as a spiral wound in opposite directions on the other face of the Ferrite body lies. The whole arrangement becomes perpendicular to the faces of the spirals of a static one Magnetic field permeated, so that in the gyromagnetic resonance state of the ferrite body a direction-dependent Coupling is achieved.

With the invention, an arrangement is specified which also makes it possible to use Lecher lines as Arrangement with a Lecher line,

in particular band line,

as a one-way line

Applicant:

International Standard Electric
ίο Corporation, New York, NY (V. St. A.)

Representative: Dipl.-Ing. H. Ciaessen, patent attorney,
Stuttgart-Zuffenhausen, Hellmuth-Hirth-Str. 42

_X g Claimed priority:

Great Britain 24 September 1956

Leonard Lewin, George Horace Brooke Thompson

and Francois Sagnard, London,
have been named as inventors

^ώ

To train one-way lines on a gyromagnetic basis. The invention is characterized in that that a pipe stub is arranged perpendicular to the line transmitting the Lecher waves and that in the area defined by the magnetic vector of the advancing wave and the Magnetic vector of the excited, standing wave of the stump line resulting circularly polarized magnetic vector is characterized, the Ferrite body excited by the static magnetic field is arranged.

The invention and its practical implementation should be shown in one embodiment with reference to the drawing explained:

Fig. 1 shows an arrangement of the one-way line partially in section, in

FIG. 2 shows the arrangement shown in FIG. 1 in section AA .

A ribbon line is to be understood as a waveguide whose ribbon-shaped conductor is in a certain Distance from each other are parallel and in which the electromagnetic energy is normally spreads in the form of Lech waves. Such a ribbon line consists, for. B. from two ladders, of which one conductor (earth conductor) is wider than the other conductor (line conductor) and those through a dielectric layer are separated from each other, the thickness of which is a fraction of a quarter wavelength of the to transmitting frequency is. Such a band »600/351

Line can also have three strip conductors, which also run parallel. There are two of the strip conductors wider and arranged on one side each with a dielectric layer. The third, narrower one Conductor lies on the other side of the dielectric layers. The material used as the dielectric can be polystyrene, which is known under the brand name »Teflon«. It can act as a dielectric fiberglass or other materials with appropriate dielectric properties are also used will. If the shape of the waveguide allows, the dielectric can also be gaseous, e.g. B. Air or nitrogen.

Fig. 1 shows a cross section through a ribbon line with two conductors, consisting of the narrower line conductor 1, 1 'and the wider earth conductor 4, both of which lie on the opposite surfaces of the dielectric 3, which has the same width as the earth conductor. The electromagnetic energy is propagated along the ribbon line in the form of Lech waves. The magnetic vector is perpendicular to the line conductor 1, V and perpendicular to the direction of propagation. A conductor stump 5 (FIG. 2) made from one piece with the line conductor lies in the same plane as the line conductor and perpendicular to it. The width of the stub conductor 5 is preferably smaller than that of the line conductor 1, 1 '. If the length of the stump 5 is chosen correctly, about an odd multiple of a quarter operating wavelength, then the current at the base of the stump in conductor 5 and earth conductor 4 and the current transmitted in the line conductor and earth conductor past the stump are practically the same size and have a phase difference of 90 °. Thus, at the junction of the stump 5 with the line conductor 1, V, the magnetic vectors are approximately the same size, but offset from one another by 90 °, so that a region of circular polarization of the magnetic field vector is given.

A piece of ferromagnetic material, such as a cylinder 6 made of nickel-zinc ferrite with a low Curie point, lies in the area with a circularly polarized magnetic field, namely between the line conductor 1, V and the earth conductor 4, as shown in FIG 1 can be seen. The diameter of the ferrite cylinder 6 is 0.13 cm and the length is equal to the thickness of the dielectric layer 3 of the ribbon line. The ferrite body can expediently be brought into its position by drilling a hole through the earth conductor, the dielectric and the ribbon-shaped conductor, inserting the ferrite body into the hole thus created and then soldering the holes in the line conductor and in the earth conductor. The ferrite body lies at the junction of the stub 5 with the main line, the exact position not being critical. The presence of the ferrite body changes the circularly polarized magnetic field, and therefore it may be necessary to change the length of the stub 5 in order to correct the aforesaid field change. Furthermore, an auxiliary stump 9 can be provided in order to improve the adaptation ratios of the strip line. As can be seen from FIG. 2, this stump 9 lies in the same plane as the line conductor 1, 1 ′ on the dielectric 3 opposite the stump 5. Its length is, for example, one eighth and that of the stump 5 three eighths of the operating wavelength, and its width is equal to that of the stump 5.

The poles 7 and 8 of a magnet are arranged on both sides of the ferrite body 6, the pole 7 of the North Pole and Pole 8 is the South Pole. The static magnetic field in which the ferrite body 6 is located has a certain sense of direction according to the desired damping direction, and the field strength is chosen so that the ferrite can be placed in the state of gyromagnetic resonance. In the present example, the field strength is 500 Oersted for a frequency of 4000 MHz.

A wave of a certain frequency, which spreads from the

ίο Part 1 to Part 1 'of the ribbon line is propagated practically not attenuated when passing through the ferrite body 6, while a wave of the same frequency, which propagates in the opposite direction, a practically circularly polarized magnetic field generated from such a direction that it is considerably attenuated. At a frequency of 4000 MHz a damping ratio of 30: 1 was obtained for the two transmission directions.

The invention is of course not limited to the present example. With the already mentioned In the case of a double strip conductor with two wide and one narrow strip conductor, the ferrite becomes arranged within the region of circular polarization on both sides of the central strip conductor. This can be done in the manner already described by making a hole through the whole Drilled through the waveguide, the ferrite body inserts so far that it is with the inwardly facing surfaces of the two earth conductors, and then soldered the holes in these earth conductors. It can be seen that when using a coaxial line in the area of the stump, where the side arms from the outer Exit head of the main line, the field distribution is similar to that of the last one mentioned band management.

Claims (7)

PATENT CLAIMS: 1. Arrangement with a Lecher line, in particular ribbon line, as a one-way line, their Directional blocking effect through the interaction of an in-line and Ferrite body excited by a static magnetic field to gyromagnetic resonance and the circularly polarized magnetic vector of a progressing wave is caused, characterized in that a stub pipe is arranged perpendicular to the line transmitting the Lech waves and that in the area which by that of the traveling wave magnetic vector and the magnetic vector the excited, standing wave of the stub pipe resulting circularly polarized manetic The vector is characterized by the ferrite body excited by the static magnetic field is arranged. 2. Arrangement according to claim 1, characterized in that the Lecher line consists of a Ribbon line with a line conductor (1,1 '), ground conductor (3) and dielectric (4) and that one of the conductors of the stub pipe (5) is also designed as a strip conductor, with the conductor is made of one piece and is arranged perpendicular to it and in the same plane, during the other conductor is formed by the earth conductor. 3. Arrangement according to claim 1 or 2, characterized in that the length of the stub pipe (5) is preferably an odd multiple of a quarter operating wavelength. 4. Arrangement according to claim 1 or 2, characterized in that in order to improve the fitting conditions an auxiliary pipe stub (9) is provided. 5. Arrangement according to the preceding claims, characterized in that the auxiliary line stub (9) and the line stub (5) with respect to the line conductor (1, V) are arranged on opposite sides and on the same axis. 6. Arrangement according to the preceding claims, characterized in that the ferrite body (6) is embedded in the dielectric (4) and its end faces with the surfaces of the dielectric lie roughly in one plane. 7. Arrangement according to the preceding claims, characterized in that the ferromagnetic Substance is a nickel-tin ferrite. Considered publications:
U.S. Patent No. 2,755,447. 1 sheet of drawings © 809 600/351 9.58