EP3389133A1 - Dielectric waveguide cable - Google Patents

Abstract

Dielectric waveguide cable (10), in particular for use in the automotive sector, having a first dielectric (12) and a second dielectric (14), wherein a separating layer (16; 18) is formed between the first dielectric (12) and the second dielectric (14) is.

Description

FIELD OF THE INVENTION

The present invention relates to a dielectric waveguide cable and a method of manufacturing a dielectric waveguide cable.

TECHNICAL BACKGROUND

Gigahertz electromagnetic wave non-dielectric waveguide cables are known. For example, the shows US 2014/0368301 A1 a waveguide with a dielectric core and a dielectric sheath, which are surrounded by a metallic boundary.

Dielectric waveguide cables such as fiber or POF for the optical transmission of signals with a frequency in the terahertz range have long been known. Such cables usually have quartz glass or PMMA (polymethylmethacrylate).

The EP 1 619 311 5 A1 shows an advantageous dielectric waveguide cable for use in the gigahertz range.

All of the aforementioned dielectric waveguide cables have the problem that the core must withstand the processing temperature at which the sheath is applied to the core.

If the core of the processing temperature does not stand, it will fuse the core with the shell. This adversely affects the transmission characteristics of the waveguide cable.

This patent application shows an alternative approach to conventional means, such as the choice of temperature-resistant materials or the lowering of the processing temperature.

SUMMARY OF THE INVENTION

Against this background, the present invention has the object to provide a dielectric waveguide cable with improved transmission properties.

According to the invention, this object is achieved by a dielectric waveguide cable having the features of patent claim 1.

• ein dielektrisches Wellenleiterkabel, insbesondere zur Verwendung im Automobilbereich mit einem ersten Dielektrikum und mit einem zweiten Dielektrikum, wobei zwischen dem ersten Dielektrikum und dem zweiten Dielektrikum eine Trennschicht ausgebildet ist, die verhindert, dass sich das erste Dielektrikum mit dem zweiten Dielektrikum verbindet; sowie
• ein Herstellungsverfahren für ein dielektrisches Wellenleiterkabel mit den folgenden Schritten: Bereitstellen eines ersten Dielektrikums; Aufbringen einer Trennschicht auf das erste Dielektrikum, insbesondere durch Aufsprühen eines dielektrischen Trennmittels oder durch Anbringen einer dielektrischen Folie an dem ersten Dielektrikum; Aufbringen eines zweiten Dielektrikums auf die Trennschicht bei einer Temperatur von wenigstens 140 °C; wobei die Trennschicht derart ausgelegt ist, dass diese sich während dem Aufbringen nicht mit dem ersten Dielektrikum und/oder dem zweiten Dielektrikum verbindet.

Accordingly, it is provided:

• a dielectric waveguide cable, in particular for use in the automotive sector with a first dielectric and with a second dielectric, wherein between the first dielectric and the second dielectric, a separating layer is formed, which prevents the first dielectric connects to the second dielectric; such as
• a dielectric waveguide cable manufacturing method comprising the steps of: providing a first dielectric; Applying a release layer on the first dielectric, in particular by spraying a dielectric release agent or by attaching a dielectric film to the first dielectric; Applying a second dielectric to the release layer at a temperature of at least 140 ° C; wherein the separation layer is designed so that it does not bond during application with the first dielectric and / or the second dielectric.

The idea underlying the present invention is to protect a first dielectric of a dielectric waveguide cable during production by a separating layer.

The separation layer is disposed between two dielectrics and prevents the dielectrics from melting together during manufacture due to high temperatures.

Although the effects of temperature-induced changes on a dielectric, for example on the core, are rather negligible, but only if the dielectric returns to its original shape after cooling.

It is essential that the first dielectric does not bond to the second dielectric, as this would blur the transition between the first dielectric and the second dielectric.

The release layer of the invention may be provided in a waveguide cable between a core and a cladding and / or between a cladding and a cladding or between other adjacent dielectric layers.

In a production method of the present invention, it is preferable to use a separation layer having a higher melting point or vaporization point when a liquid separation layer is selected than the processing temperature at which the second dielectric is applied to the separation layer.

Alternatively, a separating layer can be selected which does not join or mix with the dielectrics even above its melting or vaporization point.

The manufacturing process has a particularly advantageous effect when the release layer is applied to the core of a dielectric waveguide cable before a second dielectric is applied to the release layer by means of extrusion or foam extrusion.

Advantageous embodiments and further developments will become apparent from the other dependent claims and from the description with reference to the figures of the drawing.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

According to a preferred embodiment of the invention, the separating layer is free of oil and / or grease. Oils or greases can evaporate at high production temperatures or form undesirable residues. Such residues have been found to be detrimental to the transmission characteristics of a waveguide cable.

Alternatively, oil or grease-containing release layers having a high evaporation temperature, preferably above about 250 ° C or above 300 ° C, may be used.

According to a preferred embodiment of the invention, the separating layer is formed as a film or as a film. The thickness of such a separation layer is between 15 .mu.m and 200 .mu.m, preferably about 25 .mu.m. It is possible to form the release layer as a commercially available film and to apply it to the core or as a film which can be sprayed, for example, as a liquid release agent on the first dielectric to form the release layer. Interface thicknesses in this range have little or negligible effect on the attenuation of the waveguide, so that there are no further restrictions on the permittivity of the separation layer.

According to a preferred development of the invention, the melting point of the separating layer is greater than a respective melting point of the first dielectric and of the second dielectric. While this is not mandatory, since separation of the first dielectric from the second dielectric is also effected upon melting of the separation layer, however, the desired effect may be increased by a significant transition between the first and second dielectrics when the separation layer is at the processing temperature Dielectrics withstands.

Particularly advantageous are separating layers with melting points of at least 250 ° C., in particular 300 ° C. These temperatures are well above the processing temperature of common materials for the first and second dielectrics, for example PE. Common processing temperatures for the dielectrics are between 130 ° C and 170 ° C.

At the aforementioned processing temperatures, for example, separating layers comprising PTFE or boron nitride are suitable for achieving the desired separation of the first dielectric from the second dielectric.

As already mentioned, the release layer according to the invention can prevent the core of the waveguide cable from bonding to the sheath when the release layer is formed between the core and the sheath.

However, the release layer of the invention can also prevent the sheath from bonding to the sheath of the waveguide cable when the release layer is formed between the sheath and the sheath.

The person skilled in the art recognizes that the separating layer according to the invention can be used between any dielectric components of a waveguide cable.

It is particularly advantageous to protect a core during foaming of a shell on the core from fusion with the shell due to high extrusion temperatures. In this way, advantages that result from the foaming of the shell can be obtained. The foaming of the shell causes the storage of air in the shell, whereby a particularly clear transition in the permittivity between the core and the shell is achieved. If the core and the shell were to fuse together when the shell was being foamed, the transition in permittivity would be significantly worsened.

According to a further preferred embodiment of the invention, the separating layer comprises metal, e.g. Aluminum on. For example, the release layer may be formed as aluminum foil or other metallic foil. When the metallic separation layer is formed between the sheath and the sheath, this improves the shielding against harmful environmental influences. Aluminum has a high melting temperature of> 600 ° C and is therefore also suitable for materials of the dielectrics with higher melting points than PE.

According to a further preferred embodiment of the invention, a difference between the permittivity of the first dielectric and the permittivity of the second dielectric is between 0.3 and 2.0, in particular between 0.5 and 1.2, more particularly approximately 0.8.

Solid materials with a permittivity of less than 2.0 are currently unknown. These differences in permittivity are thus achieved by incorporating a certain amount of air into the second dielectric. Due to a large difference in the permittivity between the first dielectric and the second dielectric, the guidance of the electromagnetic wave in the first dielectric is improved. As a result, a guide of the electromagnetic wave is possible even with small bending radii.

According to a preferred development of the invention, the first and / or the second dielectric comprises polyethylene (PE) and / or polypropylene (PP) and / or polytetrafluoroethylene (PTFE).

Although PE, PP and PTFE have not yet been used to transmit electromagnetic waves to dielectric waveguides extensive tests have shown that the materials mentioned in the gigahertz range have a low attenuation and a particularly advantageous ratio between the permittivity and the loss factor of the dielectric waveguide cable.

When using the above-mentioned materials in the automotive field, an additive for increasing the temperature resistance may be mixed.

According to a further preferred embodiment of the invention, the second dielectric is formed as a PE foam, and / or as a braid and / or as at least one band, which surrounds the first dielectric, and / or as a fleece.

It is particularly advantageous if a waveguide cable according to the invention is used in an optoelectronic connector. In an optoelectronic connector dielectric waveguide cable according to the invention is used to transmit an electromagnetic signal from plug contacts to an electronic component, such as an antenna.

Plastic foams are suitable for the storage of air with sufficient mechanical stability.

It is particularly advantageous to construct the second dielectric as a material mixture. Accordingly, the second dielectric may also comprise a plurality of foam, braid or ribbon components. In addition, a foam may have multiple dielectric layers of different materials separated by a release layer.

In this way, the second dielectric can be designed particularly advantageously with respect to mechanical and electrical properties. In addition, the permittivity of the second dielectric can be further adjusted.

According to a further preferred embodiment of the invention, the third dielectric TPE, in particular TPE S. TPE, in particular TPE S, is a dielectric with a particularly large loss factor and advantageous mechanical properties, in particular with regard to resistance to kinking, and also high flame resistance.

The present invention is particularly suitable for use in a dielectric waveguide cable according to the patent application EP 16193115 A1 , the disclosure of which is hereby incorporated by reference in this application. However, the invention is not limited to this application and can also be used in other dielectric waveguide cables.

The above embodiments and developments can, if appropriate, combine with each other as desired. Further possible refinements, developments and implementations of the invention also include combinations, not explicitly mentioned, of features of the invention described above or below with regard to the exemplary embodiments. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.

CONTENT OF THE DRAWING

Fig. 1

zeigt eine schematische Schnittsicht und Perspektivansicht eines erfindungsgemäßen dielektrischen Wellenleiterkabels gemäß einer Ausführungsform;

Fig. 2

zeigt eine schematische Schnittsicht und Perspektivansicht eines erfindungsgemäßen dielektrischen Wellenleiterkabels gemäß einer Ausführungsform.

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawing. It shows:

Fig. 1

shows a schematic sectional view and perspective view of a dielectric waveguide cable according to the invention according to an embodiment;

Fig. 2

shows a schematic sectional view and perspective view of a dielectric waveguide cable according to the invention according to an embodiment.

The accompanying figures of the drawing are intended to convey a further understanding of the embodiments of the invention. They illustrate embodiments and, together with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the stated advantages will become apparent with reference to the drawings. The elements of the drawings are not necessarily shown to scale to each other.

In the figures of the drawing are the same, functionally identical and same-acting elements, features and components - unless otherwise stated - each provided with the same reference numerals.

In the following the figures are described coherently and comprehensively.

DESCRIPTION OF EMBODIMENTS

The following Figures 1-2 each show an inventive dielectric waveguide cable according to one embodiment. The modifications according to the Figures 1-2 are, unless otherwise stated, interchangeable and combinable.

The FIG. 1 shows a dielectric waveguide cable 10 according to a first embodiment of the invention. The waveguide cable 10 comprises a dielectric core 12 for transmitting an electromagnetic wave, a dielectric sheath 14 for shielding the wave to be transmitted, and a dielectric sheath 16 for mechanical protection of the dielectric waveguide cable 10.

Between the core 12 and the shell 14, a dielectric separation film 18 sprayed on the core is formed.

FIG. 2 shows a dielectric waveguide cable 22 according to a second embodiment of the invention. Similar to FIG. 1, the cable 22 has a core 12, a shell 14 and a jacket 16. Between the core 12 and the shell 14, a dielectric release film 20 made of PTFE, which has been applied to the core, is formed.

It is understood that between the core and the shell also a film may be formed or that between the shell and the shell and a film may be formed.

A film differs from a film in that a film is in a solid state of aggregation, whereas a film can also be in a liquid state of aggregation. It can be provided that the film becomes solid or remains liquid after a drying time or curing time.

It is understood that the cables according to FIG. 1 and FIG. 2 can also be combined with each other, so that both between the core and the shell and between the shell and the shell in each case a separating layer can be provided.

LIST OF REFERENCE NUMBERS

10

dielectric waveguide cable

12

first dielectric / core

14

second dielectric / shell

16

third dielectric / cladding

18

Interface

20

Interface

22

dielectric waveguide cable

Claims (15)

Dielectric waveguide cable (10), in particular for use in the automotive sector, having a first dielectric (12, 14) and a second dielectric (14, 16),
wherein between the first dielectric (12, 14) and the second dielectric (14, 16) a separating layer (18; 20) is formed which prevents the first dielectric from bonding to the second dielectric. A dielectric waveguide cable (10) according to claim 1, wherein said separation layer (18; 20) is made of a dielectric material. Dielectric waveguide cable (10) according to one of the preceding claims, wherein the separating layer (18; 20) is formed as a film or as a film. Dielectric waveguide cable (10) according to one of the preceding claims, wherein the separating layer (18; 20) is at most 200 μm, in particular at most 80 μm, more particularly at most 30 μm thick. The dielectric waveguide cable (10) of any one of the preceding claims, wherein the separation layer has a melting point greater than a respective melting point of the first dielectric and the second dielectric. Dielectric waveguide cable (10) according to any one of the preceding claims, wherein the melting point of Separation layer above 250 ° C, especially at about 300 ° C, is located. Dielectric waveguide cable (10) according to any one of the preceding claims, wherein the separating layer comprises PTFE and / or boron nitride. A dielectric waveguide cable (10) according to any one of the preceding claims, wherein the first dielectric is formed as a core of the dielectric waveguide cable and the second dielectric is formed as a cladding to the core of the dielectric waveguide cable. Dielectric waveguide cable (10) according to claim 8, which comprises a third dielectric (16), which is formed as a cladding to the sheath (14) of the waveguide cable, wherein between the second and the third dielectric, a further separation layer (20) is formed. Dielectric waveguide cable (10) according to one of the preceding claims 1-7, wherein the first dielectric is formed as a shell of the dielectric waveguide cable and the second dielectric is formed as a cladding to the shell of the dielectric waveguide cable. Dielectric waveguide cable according to claim 10, wherein the separating layer comprises metal, in particular aluminum. Dielectric waveguide cable according to one of claims 8 or 9, wherein in the second dielectric air is stored and wherein the second dielectric is foamed onto the release layer. Dielectric waveguide cable according to one of the preceding claims, wherein the permittivity of the second dielectric is less than 2 and / or a difference between the permittivity of the first dielectric and the permittivity of the second dielectric at least 0.3, in particular at least 0.5, more particularly at least 0th , 8 is. An optoelectronic connector for connecting a dielectric waveguide to an electrical lead comprising a dielectric waveguide cable according to any one of the preceding claims. A dielectric waveguide cable manufacturing method comprising the following steps: - Providing a first dielectric; - Applying a release layer to the first dielectric, in particular by spraying a release agent or by attaching a film to the first dielectric; - Applying a second dielectric to the release layer at a temperature of at least 100 ° C, in particular at least 120 ° C; wherein the separation layer is designed so that it does not bond during application with the first dielectric and / or the second dielectric.

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