Antenna structure

Abstract

The invention relates to an antenna structure comprising a waveguide, in which the waveguide has a guide element for guiding a wave, in which a capping structure is provided adjacent to the guide element, said capping structure protruding away from the guide element.

Description

Technical Field

[0001] The invention relates to an antenna structure, in particular for applications in the radio frequency range, comprising a waveguide, wherein the waveguide has a guide element for guiding the waves. Background Art

[0002] Such antenna structures are used, for example, to guide and / or output electromagnetic waves. Electromagnetic waves, in particular radio frequency signals, can propagate either in space or in a waveguide. Such a waveguide is provided with a conducting structure, which comprises a spatial region and thus forms a spatial path or channel, in order to guide electromagnetic waves or radio frequency signals therein or to manipulate electromagnetic waves or radio frequency signals in a spatial or frequency range or to emit electromagnetic waves or radio frequency signals in said spatial or frequency range.

[0003] In many applications of radar sensor devices, an "all-round view" of an antenna structure is very advantageous. Technically, achieving such an all-round view often proves to be quite difficult.

[0004] Fig.14 A cross-sectional view of a conventional hollow conductor slot antenna is shown, which includes a hollow conductor 10 having one or more slots S at its upper wall. The main radiation area of ​​the hollow conductor slot antenna 10 is indicated by A. As can be seen from the figure, instead of detecting or supplying the entire space around the hollow conductor, only the partial circle schematically shown here is detected or supplied. In areas not detected by the partial circle, for example beside and below the antenna, the antenna is "blind".

[0005] To solve the problem, it is conceivable to set another hollow conductor slot antenna with a slot facing downward below the hollow conductor slot antenna shown. Therefore, from a conventional point of view, it is conceivable to divide the space into multiple sections, which are covered by multiple antennas independently or partially overlapping each other.

[0006] Due to the spatial arrangement of the elements (array configuration) and the spatial distance of the hollow conductor slot antenna (usually larger than 1 / 2λ), the described scheme is accompanied by a very irregular gain profile.

[0007] Other solutions use slot antennas on circular hollow conductors, for example, in which the space is illuminated in all directions. However, due to the design, the integration of multiple such antennas for MIMO radar systems proves to be difficult, because these antennas always interfere with each other, since all sides of the circular hollow conductor must be slotted. Summary of the invention

[0008] The invention is therefore based on the object of developing an antenna structure of the type mentioned in the introduction in such a way that a uniform all-round detection of the room or an all-round radiation into the room is possible.

[0009] This object is achieved by an antenna structure having the features of claim 1. It is proposed that adjacent to the guide element, i.e., adjacent to the hollow conductor slot antenna, a terminating structure is provided which protrudes from the guide element, i.e., projects. The terminating structure can be designed, for example, in the form of a wing or in another way.

[0010] Surprisingly, it has been found that a very uniform all-round detection or emission range is obtained by means of such a structure. The radiated or received electromagnetic waves are influenced by the end structure so that the radiated or received electromagnetic waves are uniformly distributed in the surrounding environment. Fig.14 The area shown in FIG. 1 covers a larger area than that shown in FIG. 4 , so that blind positions can be reduced or completely avoided depending on the arrangement of one or more waveguide or radiating gaps and the like and the end capping structure.

[0011] The guide element can be a dielectric waveguide which preferably has one or more electrically conductive strips (dielectric antenna: conductor and non-conductor are interchanged here).

[0012] It is particularly preferred that the guide element is a hollow conductor, which comprises a guide channel, the inner surface of which is at least partially electrically conductive, wherein the guide channel has a first wall, which has one or more interruptions. Therefore, a preferred embodiment consists of a hollow conductor which is provided with radial slots at least on one side, at least one non-radiating side of the hollow conductor being terminated with an end structure, which is a "surface end structure", in particular an end structure with a triangular cross section.

[0013] The guide element is preferably elongated and can be designed to be straight or curved. This applies to the end capping structure accordingly.

[0014] The guide element can have a longitudinal axis, wherein the end structure extends in the direction of the longitudinal axis of the guide element and preferably parallel to the longitudinal axis of the guide element.

[0015] The terminating structure can have a different cross-sectional shape than the guide element. Thus, for example, it is conceivable that the guide element, that is to say the hollow conductor, has a rectangular cross section and the terminating structure has a triangular or circular cross section.

[0016] It is conceivable that the end structure is designed as a compact body, ie as a body without a cavity, or as a hollow body.

[0017] In one embodiment, the cross section of the end capping structure is polygonal, preferably triangular or circular. For example, partially circular, triangular, polygonal, etc. structures are conceivable.

[0018] In another embodiment, the guide channel has a second wall, wherein the second wall is a non-radiating side of the hollow conductor, and wherein the terminating structure extends from the second wall.

[0019] Within the scope of the present invention, the terms "break", "gap" etc. may represent such an opening, which leads to an improved accessibility to process media, such as ink for coating. The opening is a non-radiating opening. A wall with such an opening is also called a non-radiating wall or a non-radiating side etc.

[0020] The terms "break", "slit", etc. also include openings for radiating waves. The openings cut the current density distribution on the inner wall of the hollow conductor not perpendicular to its flow direction. Within the scope of the present disclosure, the openings are also referred to as radiating breaks, radiating slits, etc. A wall with such an opening is also referred to as a radiating wall or radiating side, etc.

[0021] In detail, this is achieved in particular in that the non-radiating opening is significantly smaller than half a wavelength and is oriented in the direction of flow of the current, for example “from top to bottom” on the narrow side.

[0022] The non-radiating opening has in particular a very small shape (a small rectangular opening), wherein the term "small" means small relative to the wavelength: in particular less than 1 / 4 of the wavelength.

[0023] Furthermore, it can be provided that the guide channel has a third wall, which has one or more interruptions, wherein the third wall is preferably arranged opposite the first wall. Thus, the third wall can also be a radial wall, for example.

[0024] Furthermore, the guide channel can have a fourth wall, to which the further end structure adjoins, wherein provision is preferably made for the fourth wall to be arranged opposite the second wall.

[0025] Preferably, the fourth wall is a non-radiating side of the hollow conductor.

[0026] The end cap preferably extends over more than half the length of the guide element, preferably over more than ¾ of the length of the guide element, and particularly preferably over the entire length of the guide element.

[0027] It is particularly advantageous if the end capping structure is in at least one region in which the guide element has radial breaks in its wall, preferably in the region of greatest radiation of the guide element or even over the entire radiation region of the guide element, wherein the radiation region of the guide element is characterized in that in said region radial breaks are present in at least one of the walls of the guide element.

[0028] The terminating structure can have a flat side which abuts against a side of the guide element, wherein it is preferably provided that the two sides abutting against one another have the same height and / or width.

[0029] Furthermore, it is conceivable that the end structure has a side, preferably an edge, which faces away from the side of the guide element from which the end structure extends. For example, it is conceivable that the end structure tapers away from the guide element, preferably tapers to a point.

[0030] The end-capping structure is preferably a three-sided prism.

[0031] The closure structure can be formed integrally with the hollow conductor. It is also conceivable that the closure structure and the hollow conductor are formed by connected separate parts.

[0032] Furthermore, it can be provided that the side of the end structure facing away from the waveguide, preferably its edge, is designed to be straight or wavy or to have one or more recesses, preferably to have a sawtooth-like structure. The edge structure can have the end structure over its entire length or only in a partial region of the edge structure. In its longitudinal orientation, the end structure can be, for example, sawtooth-like or wavy along the edge.

[0033] The antenna structure can have exactly one waveguide or a plurality of waveguides arranged side by side and / or one above the other. Thus, the antenna structure can have an array of waveguides.

[0034] Thus, for example, pairs of hollow conductors with slots on one side can be conceived, which are arranged "back to back" next to each other, so that one of the hollow conductors radiates upward and the other of the hollow conductors radiates in the opposite direction. The two hollow conductors can be fed via a power divider, which has the advantage that different radiation characteristics can be obtained at the front and rear or at opposite sides of the antenna structure.

[0035] It is conceivable that each waveguide, in particular a hollow conductor, in the waveguide is provided with one or more end structures. It is also conceivable that a plurality of hollow conductors have a common end structure.

[0036] In a further embodiment, the guide channel is filled with air or a dielectric, in particular with a ceramic.

[0037] The waveguide can be a hollow waveguide or an antenna, in particular a horn antenna, or a filter or a resonator or a coupler or other passive radio frequency components. The antenna structure can have one or more of the above-mentioned components, which are preferably realized in a common component.

[0038] The guiding element may be terminated at the end, for example by a short circuit or by an open circuit (whereby a standing wave may be generated, which is a resonant antenna).

[0039] Preferably, the antenna structure is a radar sensor device or a part of a radar sensor device.

[0040] The antenna structure can be flat or can be designed conformally on a curved surface shape.

[0041] It is conceivable that the antenna structure has slots or other interruptions as radiating elements on one or two or more than two sides, preferably on two opposite sides, for example at the top and / or the bottom.

[0042] The cross section of the guide element can be designed such that its height is preferably smaller than half its width.

[0043] The cross section of the guide element can be rectangular, polygonal, circular, rounded or oval or in another manner.

[0044] One or more pairs of hollow conductors with slots on one side, which lie against one another with their backs, and a power divider for feeding the hollow conductors may be provided.

[0045] Furthermore, the invention relates to a method for producing an antenna structure according to any one of claims 1 to 24, wherein the guide element is produced partially or completely by means of an additive method, in particular 3D printing, SLS printing, metal printing, SLA-3D printing, cutting or by means of plastic injection molding.

[0046] The antenna structure and / or its waveguide may be produced monolithically or from a plurality of components.

[0047] In another embodiment of the invention, the method comprises: immersing the waveguide once or multiple times into an infiltration bath, in particular an ultrasound bath, containing a dispersion, wherein the dispersion has metal-containing particles, in particular gold particles and / or silver particles and / or copper particles.

[0048] Furthermore, it can be provided that, before coating, one or more slots are introduced through the wall into the wall of the base body forming the inner surface of the base body in order to promote circulation of the dispersion in the cavity or in the region of the inner surface of the hollow conductor.

[0049] The radio frequency component according to the invention can have a 3D printed or injection molded plastic substrate forming the basis of the hollow conductor. For the subsequent function, the radio frequency component must be provided with an electrically conductive coating.

[0050] In this case, in particular galvanic or electroless coating with metals and also chemical coatings in which a chemical reaction takes place between a reagent liquid and the surface of the body to be coated.

[0051] However, the method known from DE 10 2020 104 038.5 is particularly advantageous. The disclosure of the patent application is hereby fully referenced. Here, the necessary conductive coating of the substrate is achieved in the following way: at least a part of the substrate of the hollow conductor, preferably the entire surface, is wetted with a dispersion containing conductive microparticles and / or nanoparticles. The dispersion can be an ink with microparticles or nanoparticles. Conceivable nanoparticles are aluminum particles, silver particles, gold particles or copper particles or mixtures thereof. Here, the dispersion or ink is coordinated with the surface energy of the substrate material used, such as plastic, so that it is conducive to sufficient wetting of the surface.

[0052] After the solvent / water evaporates / volatizes, the surface of the substrate is wetted with the ink material and an electrically conductive coating is formed by optional post-treatment, preferably by thermal action, such as by sintering. Thus, the method is physical wetting, wherein the electrically conductive coating is formed by post-treatment.

[0053] At this point it is to be noted that the terms "a" and "an" do not necessarily refer to exactly one of the elements, although this is a possible embodiment, but may also refer to a plurality of the elements. Likewise, the use of the plural number also includes the presence of the referenced elements in the singular, and vice versa, the singular also includes a plurality of the referenced elements.

[0054] Furthermore, it is pointed out that any feature disclosed may be combined with any other feature disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Further details and advantages of the invention are explained in greater detail with reference to the exemplary embodiments shown in the drawings.

[0056] The accompanying drawings show:

[0057] Figure 1 A perspective view of a hollow conductor slot antenna structure is shown, wherein the hollow conductor slot antenna structure has a hollow conductor together with a capping structure arranged on one side,

[0058] Figure 2 The longitudinal section shows Figure 1 A view of the device,

[0059] Figure 3 The cross section shows Figure 1 A view of the device,

[0060] Figure 4 A three-dimensional view of a waveguide system is shown, wherein the waveguide system has three single hollow conductors arranged side by side with end capping structures arranged on both sides,

[0061] Figure 5 The longitudinal section shows Figure 4 A view of the device,

[0062] Figure 6 The cross section shows Figure 4 A view of the device,

[0063] Figure 7 A perspective view of a hollow conductor slot antenna structure is shown, wherein the hollow conductor slot antenna structure has a hollow conductor with end caps arranged on both sides.

[0064] Figure 8 The cross section shows Figure 7 A view of the device,

[0065] Fig. 9 A three-dimensional view of a hollow conductor slot antenna structure is shown, wherein the hollow conductor slot antenna structure has three individual waveguides arranged side by side with end structures arranged on both sides, wherein a break is provided in the end structure,

[0066] Fig.10 The longitudinal section shows Fig. 9 A view of the device,

[0067] Fig.11 The cross section shows Fig. 9 A view of the device,

[0068] Fig.12 A schematic diagram showing the radiation or reception area of ​​the antenna structure according to the present invention in a hollow conductor with a capped structure,

[0069] Fig.13 A schematic diagram showing the radiation or reception area of ​​the hollow conductor slot antenna structure according to the present invention in two hollow conductors arranged back to back and each having a terminating structure;

[0070] Fig.14 Schematic diagram showing the radiation or reception area of ​​a hollow conductor slot antenna structure in a hollow conductor without a termination structure. DETAILED DESCRIPTION

[0071] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0072] Figure 1 The hollow conductor is shown at 10, as shown in FIG. Figure 2 As can be seen in FIG. 1 , the hollow conductor has a first wall 1 and a third wall 3 , each of which is provided with a slit S. The two walls 1 , 3 are therefore the radiating sides of the hollow conductor 10 .

[0073] The side walls of the hollow conductor 10 are perpendicular to the walls 1, 3, so that the cross-section of the hollow conductor 10 is rectangular. The side walls 2, 4 are closed, that is to say have no radial slots. However, the side walls can also have non-radial slots for processing.

[0074] Said side of the hollow conductor is therefore not radial. Figure 1 Only side wall 2 of the side walls can be seen.

[0075] The end structure 20 is connected to the side wall 4 of the hollow conductor 10 opposite to the side wall 2. The cross section of the end structure 20 is triangular, wherein the sides 21, 22 of the triangle are much longer than the bottom side 23 thereof, so that a gradually tapering triangle is obtained. Figure 1 As can be seen in FIG. 1 , the tip S points away from the hollow conductor 10 .

[0076] The length of the bottom side 23 corresponds to the height of the hollow conductor 10 , so that the terminating structure protrudes neither above nor below the hollow conductor.

[0077] The triangular angle of the tip is preferably less than 45°, particularly preferably less than 20°.

[0078] The triangle is preferably an equilateral triangle.

[0079] from Figure 3 It can be concluded that the end-capping structure is compacted, that is, it is not hollow.

[0080] The hollow conductor 10 and the terminating structure 20 are two-piece, ie, they are not formed from the same component.

[0081] Figure 4 An embodiment is shown in which three hollow conductors 10 are arranged side by side, such as this in particular by Figure 5 and Figure 6 As obtained from the cross-sectional view.

[0082] Each of the hollow conductors 10 has slots at the upper and lower parts, that is, the antenna structure is double-sided radiating.

[0083] The three hollow conductors are monolithic, ie consist of a common component.

[0084] The two hollow conductors located outside are provided with a respective terminating structure 20 on the outer walls of the corresponding sides. The terminating structures provided on both sides are arranged in a mirror-symmetrical manner with respect to the central plane of the antenna structure.

[0085] Figure 7 and Figure 8 The three-dimensional and cross-sectional views are shown according to Figure 1 The embodiment of the present invention is different in that, however, a terminating element 20 is connected to each of the two side walls of the hollow conductor slot antenna structure. The terminating elements point in different opposite directions at their tips.

[0086] Figures 9 to 11 A further embodiment is shown with three adjacently arranged hollow conductors 10 which are formed from a single element. Furthermore, the hollow conductor is produced in one piece, but is hollow and has interruptions.

[0087] Different from the above embodiment, Figures 9 to 11 In the embodiment of the present invention, the end-capping structure 20 has a cavity and a fracture portion 30. The fracture portion is preferably a non-radiating fracture portion.

[0088] This is located above and below in the wall of the closure element in the region of the cavity.

[0089] Furthermore, the breaks in the terminating element are also arranged in regions where no cavities are present.

[0090] Fig.12 The radiation area A of the hollow conductor slot antenna structure according to the present invention is shown. The hollow conductor slot antenna structure includes a hollow conductor 10 with a slot (slot S) and a termination structure 20 .

[0091] In contrast, Fig.14 FIG. 4 shows a radiation area A of a hollow conductor slot antenna structure not according to the present invention, wherein the hollow conductor slot antenna structure includes: Fig.12 The same hollow conductor 10 in FIG. 1 , but without the terminating structure. From the comparison of these figures, it is clear that the radiation area of ​​the antenna structure under the same operating conditions is significantly increased only by the presence of the terminating structure 20 and in particular also includes the area next to the hollow conductor 10 .

[0092] Fig.13 The diagram illustrates that in the embodiment, a very uniform "all-round" radiation area A is obtained, in which two hollow conductors 10 are respectively provided with a gap S on their free outer sides back to back, wherein the hollow conductors are provided with end elements 20 at their free sides. Each of the end elements 20 has a height that corresponds to the height of the two hollow conductors arranged one above the other.

[0093] In principle, in order to achieve this result, it is also possible to use a single hollow conductor radiating upward and downward, which is provided with a terminating element 20 on each side.

[0094] Preferred non-limiting embodiments of the invention are described below.

[0095] A "surface-terminated structure" is used, especially one with a polygonal cross section, and the non-radiating hollow conductor side is used for termination.

[0096] Other cross-sections of the end structure are also entirely conceivable, for example circular, polygonal.

[0097] The end capping structure can be serrated or wavy along its edge in the longitudinal direction, or can also be embodied straight.

[0098] Advantageous are particularly flat hollow conductors, preferably with a height of less than half the width, for example: width: 3 mm to 4 mm & height: 1 mm at 60 GHz to 90 GHz.

[0099] Preferably, the hollow conductor is slotted on two sides (on a side group). A side group is either two wide sides or two narrow sides.

[0100] A hollow conductor is proposed which is provided with radial slots at least on one side, wherein at least one non-radiating side of the hollow conductor is terminated with a “surface termination structure”, in particular a triangular cross section.

[0101] The cross-sectional shape of the hollow conductor may be rectangular, but may also be completely circular or generally oval or other shapes.

[0102] It is conceivable to integrate a plurality of such antennas into a structure having a common surface.

[0103] An array of such antennas is preferred. Such an array can be used, for example, in a MIMO system (Multiple Input Multiple Output=MIMO) (here a system concept from radar technology).

[0104] Pairs of hollow conductors which are slotted on one side (very narrow or small) and which bear against each other with their backs and are fed via a power divider are also conceivable, with the advantage that different emission characteristics are present at the front and rear or on both sides.

[0105] The waveguide can be flat, but can also be formed completely conformally to the shape of a curved surface.

[0106] Instead of air, the hollow conductor can also be filled dielectrically, for example with ceramic.

[0107] Instead of an electrically conductive hollow conductor with a slot for emission, a dielectric waveguide with electrically conductive strips (dielectric antenna, in which conductor and non-conductor are interchanged) is also conceivable.

[0108] The hollow conductor with slots can have a base body with non-radiating slots for electroplating. In the case, there are additional slots, etc., so that the material of the inner side of the coating base body is particularly well introduced into the interior of the hollow conductor base body.

[0109] The hollow conductor may be manufactured as a 3D printed part (metal and / or plastic) with subsequent cladding.

[0110] The hollow conductor can be produced in one piece or from a plurality of parts (ie conventionally) or as an injection-molded part or conventionally.

[0111] An advantageous field of application of the waveguide device according to the invention is “all-round vision”, ie the detection of waves from the surroundings or the emission of waves into the surroundings over 360°.

Claims

1. An antenna structure comprising a waveguide, wherein the waveguide has a guiding element for guiding waves, characterized in that A capping structure is disposed adjacent to the guide element and extends away from the guide element.

2. The antenna structure according to claim 1, characterized in that: The guide element is a dielectric waveguide which preferably has one or more electrically conductive strips.

3. The antenna structure according to claim 1, characterized in that: The guide element is a hollow conductor which comprises a guide channel, the inner surface of which is at least partially electrically conductive, wherein the guide channel has a first wall which has one or more radial interruptions.

4. The antenna structure according to claim 3, characterized in that: The guide channel has one or more walls, and the interruption is provided in one, a plurality of or all of the walls.

5. The antenna structure according to any one of the preceding claims, characterized in that: The guide element has a longitudinal axis and the end structure extends in the direction of the longitudinal axis and preferably parallel to the longitudinal axis of the guide element.

6. The antenna structure according to any one of the preceding claims, characterized in that: The end structure has a different cross-sectional shape than the guide element and / or the end structure is more compact or is designed as a hollow body.

7. The antenna structure according to any one of the preceding claims, characterized in that: The cross section of the end structure is polygonal, preferably triangular or circular, and / or the guide element terminates at an end.

8. The antenna structure according to any one of claims 3 to 7, characterized in that: The guide channel has a second wall, wherein the second wall is a non-radiating side of the hollow conductor, and wherein the terminating structure extends from the second wall.

9. The antenna structure according to any one of claims 3 to 8, characterized in that: The guide channel has a third wall which has no interruption, one interruption or a plurality of interruptions, wherein the third wall is preferably arranged opposite the first wall.

10. The antenna structure according to any one of claims 3 to 9, characterized in that: The guide channel has a fourth wall having a further end capping structure, wherein the fourth wall is preferably arranged opposite the second wall.

11. The antenna structure according to claim 10, characterized in that: The fourth wall is a non-radiating side of the hollow conductor.

12. The antenna structure according to any one of the preceding claims, characterized in that The end capping structure is in at least one area in which the guide element has radial breaks in its wall, preferably however in the area of ​​maximum radiation of the guide element or even in the entire radiation area of ​​the guide element, wherein the radiation area of ​​the guide element is characterized in that in said area there are radial breaks in at least one of the walls of the guide element.

13. The antenna structure according to any one of the preceding claims, characterized in that The end capping structure extends over more than half of the length of the guide element, preferably over more than ¾ of the length of the guide element, and particularly preferably over the entire length of the guide element.

14. The antenna structure according to any one of the preceding claims, characterized in that The closure structure has a side which bears against a side of the guide element, wherein it is preferably provided that the two sides have the same height and / or width.

15. The antenna structure according to any one of the preceding claims, characterized in that The closure structure has a side, preferably an edge, which faces away from the side of the guide element from which the closure structure extends.

16. The antenna structure according to claim 15, characterized in that: The side, preferably the edge, is designed to be straight or wavy or has one or more recesses, preferably has a sawtooth-like structure and / or tapers.

17. The antenna structure according to any one of the preceding claims, characterized in that The antenna structure has exactly one waveguide or guide element or a plurality of waveguides or guide elements and / or antenna structures which are arranged next to one another and / or one above the other.

18. The antenna structure according to any one of claims 3 to 17, characterized in that: The guide channel is filled with air or with a dielectric, in particular with a ceramic.

19. The antenna structure according to any one of the preceding claims, characterized in that The waveguide is a hollow waveguide or an antenna, in particular a horn antenna, or a filter or a resonator or a coupler or other radio frequency components.

20. The antenna structure according to any one of the preceding claims, characterized in that The antenna structure is flat or conformally designed on a curved surface shape.

21. The antenna structure according to any one of the preceding claims, characterized in that The antenna structure has slots or other interruptions as radiating elements on one or two or more than two sides, preferably on two opposite sides, for example at the top and / or the bottom.

22. The antenna structure according to any one of the preceding claims, characterized in that The cross section of the guide element is designed such that the height of the guide element is preferably smaller than half the width.

23. The antenna structure according to any one of the preceding claims, characterized in that The cross section of the guide element can be rectangular, polygonal, circular, rounded or elliptical in some other manner.

24. The antenna structure according to any one of the preceding claims, characterized in that The antenna structure has one or more pairs of hollow conductors with slots on one side and which are in contact with each other with their backs, and the antenna structure has a power divider for feeding the hollow conductors.

25. A method for manufacturing an antenna structure according to any one of claims 1 to 24, characterized in that: The guide element is produced partially or completely by means of an additive method, in particular 3D printing, SLS printing, metal printing, SLA 3D printing, by cutting or by means of plastic injection molding.

26. The method according to claim 25, characterized in that The waveguide structure can be manufactured monolithically or from a plurality of components.

27. The method according to claim 25 or 26, characterized in that The method comprises immersing the guide element once or several times into an immersion bath, in particular an ultrasound bath, containing a dispersion, wherein the dispersion has metal-containing particles, in particular gold particles and / or silver particles and / or copper particles.

28. The method according to any one of claims 25 to 27, characterized in that The method comprises the step of galvanically or electrolessly coating the guide element.

29. The method according to any one of the preceding claims, characterized in that Prior to the coating, one or more slots or other breaks through the wall are introduced into the wall of the base body forming the inner surface of the base body in order to promote the circulation of the dispersion in the cavity or in the region of the inner surface.

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