DE2022990A1 - High frequency line - Google Patents

Description

K a. h e 1 - and metal, works Gntehoffmm.TRhütte Aktiengesellschaft

3 166 .11. 5. 70

High frequency pnz.lei

The invention relates to a high frequency line with a partial external field in which the conductors are surrounded by a dielectric, which is itself a metallic one Screen is surrounded.

For the transmission of HF signals from stationary transmission equipment «· services to mobile receivers or vice versa, in particular for radio transmission in tunnels between stations and receiving devices in rail vehicles, cables are used, which Both transmit and radiate the HF energy with little loss. For this purpose it has already become known to use symmetrical, Use unshielded HF cables, for example so-called ribbon cables. Such lines have losses that are strongly dependent on environmental influences and weather conditions and radiation properties, especially if they are fastened flat to any surface. A radiating, approximately coaxial line has also become known, a so-called slot line, in which flor outer conductor surrounds the concentric insulation of the inner conductor only over part of the circumference. The radiation thus takes place through the slot remaining in the outer conductor. A disadvantage of such an arrangement is to be seen in the fact that that the field strength increases with increasing distance from the line

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rapidly decreasing ", to achieve sufficient information for the receiver would accordingly EINP relatively high energy to be fed to the line which is limited by the dimensions of the conductor _o

A third possibility for obtaining the necessary information would be to give the HF line larger dimensions, which not only makes it expensive and therefore uneconomical, but also considerably more difficult. Another disadvantage of the known high-frequency lines is that Although their field is suitable for inductive or capacitive decoupling to the input of a receiver, this field is highly scattering and accordingly subject to dielectric losses, so that there is great attenuation of the energy to be transmitted.

The invention is based on the object of specifying a radiating high-frequency line in which the losses on the line are as low as possible and are independent of the weather. This object is achieved according to the invention with a high-frequency line of the kind that the concentric return conductor bsw, the screen completely surrounding the conductor or conductors in the form of a closed Hohres so that ei "Stroea is based on Desj Leitungssüittel" point, can only spread helically in it. Through the

■;. · ._. a according to esa Äirfban / Ho-chfrequenzleitung results of VoJTufc .. ·· \ ₉ that the electrically © field or not from the closed re-circulation ₀ Screen emerge Kawm "ad therefore no umgefoungsabhängigea dielectric losses are erseugt. The only field that remains is the inductive field created by the helical structure of the return conductor, which is ideally suited for extraction at a receiver

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SAD ORIGINAL

An exemplary embodiment of the invention is + in the drawings darsestei It.

FIGS. 1 and 2 show cross sections through two differently constructed high-frequency lines. In Fig. 35st a high-frequency line with partially removed individual layers is shown schematically, and Fig. H shows a possible form of the return conductor or screen in the unwound position.

With 1 is the back ^ iter of a coaxial high-frequency line |

whose concentric return conductor bears the designation. The return conductor is through the dielectric 3 from the Hin-If.;. ^; + it 1 separated and surrounded on the outside by the jacket 4.

In FIG. 2, forward and return conductors are formed by a parallel line pair 5 and 6, which are surrounded by the screen 7. The dielectric is again labeled 3 and the outer jacket is again labeled k.

According to the invention, the return conductor 2 according to FIG. 1 or the screen 7 according to FIG. 2 is designed in the form of a tube and completely closed. gan ?: or partially insulated wires that lie close together and thus represent the closed pipe. In addition to the embodiment shown in FIG. 3, however, it is also possible to construct the return conductor 2 or the screen 7 from a metal strip applied helically to the dielectric 4. The individual turns of this metal strip can be overlapped thereby, but they must be at least close to each other so that no gap remains between them _r

ÜH / GJNAL 10 9 8 4 9/1502

Another possibility for forming the return conductor 2 or screen 7 is shown _{in FIG. 1} T. k , in which a metal strip 9 is shown, which is provided with slots 10. This metal band 9 is running lengthways around the
Dielectric 3 berum formed into a tube. The slots ensure that the flow is not in an axial direction
Can spread in the direction of the line, but must run helically, since the slots have an axial current path
do not leave 7 ".

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Claims (3)

Kabel- und Metallwerke Gutehoffnungshütte Aktiengesellschaft 3 166 11. 5 «70 Patents 1. High frequency! Eitunc with a nartial external field., Which ans an outward conductor with a concentric return conductor λ or from the back surrounded by a metallic screen and return conductor exists, because it is marked that the concentric return conductor (2) or the screen (?) the conductor or conductors (1,5,6) in the form of a closed The tube completely surrounds it in such a way that a current only spreads in a helical manner in relation to the center point of the line can. 2. High-frequency line according to claim 1, characterized in that the concentric return conductor (2) or screen (7) is made up of a layer of completely or partially insulated, helically applied wires (8). 3. High frequency line according to claim 1, characterized in that that the concentric return conductor (2) or screen (7) is constructed from a helically applied metal strip is. H. High-frequency conductor according to Claim 1, characterized in that the concentric return conductor (2) or screen (7) is constructed from a metal band (Q) shaped into a tube and provided with slots (10) through which the metal band is helically shaped Strip is divided. 109849/1502 BAÖ ORIGINAL Blank page