Waveguide part for an antenna device, antenna device and method for producing a waveguide part for an antenna device

Abstract

The present invention relates to a waveguide component for an antenna device comprising a one-piece, two-piece, or multi-piece waveguide (10) which at least partially surrounds an inner volume (12), wherein the waveguide (10) has a mass fraction of aluminum of at least 50 wt.% and / or a metal coating (22) with a mass fraction of aluminum of at least 50 wt.% is formed on and / or over at least one surface (16) of the waveguide (10) oriented towards the inner volume (12). In particular, the waveguide (10) can be at least partially formed from a plastic and the metal coating (22) arranged on and / or over the at least one surface (16) of the waveguide (10) oriented towards the inner volume (12) can have a mass fraction of aluminum of at least 50 wt.%.Alternatively, the one-piece waveguide, two waveguide components (10a, 10b) of the two-piece waveguide (10) or all at least three waveguide components of the multi-piece waveguide can be structured from at least one block of material with a mass fraction of aluminium of at least 90 wt.%.

Description

[0001] The present invention relates to a waveguide component for an antenna device. The present invention also relates to an antenna device. Furthermore, the present invention relates to a manufacturing method for a waveguide component for an antenna device. State of the art

[0002] In WO 2024 / 153357 A1, a waveguide antenna and a method for its manufacture, or a power distribution device formed therewith, are described. Disclosure of the invention

[0003] The present invention provides a waveguide part for an antenna device with the features of claim 1, an antenna device with the features of claim 11 and a manufacturing method for a waveguide part of an antenna device with the features of claim 12. Advantages of the invention

[0004] The present invention provides waveguide components, or antenna devices equipped with waveguide components, which, due to the design of a waveguide component with a mass fraction of aluminum of at least 50 wt.% (weight percent) and / or its metal coating with a mass fraction of aluminum of at least 50 wt.% (weight percent), are significantly better suited for their standard functions compared to a conventional aluminum-free waveguide. In particular, a waveguide component obtained by means of the present invention exhibits high electrical conductivity, especially for electromagnetic waves with frequencies in the radio frequency range, specifically frequencies between 76 GHz (gigahertz) and 81 GHz (gigahertz), which enables relatively low-loss propagation of such electromagnetic waves.Since aluminum is a relatively inexpensive material, the present invention also enables the production of waveguide components, or antenna devices equipped with them, at comparatively low manufacturing costs. A further advantage of a waveguide component obtained by means of the present invention is the comparatively high robustness of the waveguide component, achieved through the use of aluminum, even under extreme temperatures, such as in a temperature range between -40 °C and 130 °C, extremely strong (shock-like) temperature fluctuations, and in an environment with chemically reactive materials. Therefore, the waveguide components obtained by means of the present invention are also well suited for use in the automotive sector, although their application is not limited to this sector.

[0005] In an advantageous embodiment of the waveguide component, the waveguide is at least partially molded from a plastic and has a metal coating arranged on and / or over the at least one surface of the waveguide oriented towards the inner volume, with a mass fraction of aluminum of at least 50 wt.%. By manufacturing the waveguide from the plastic and subsequently forming the metal coating described here, a robust combination of materials is achieved in the waveguide component, which exhibits high electrical conductivity and is therefore well-suited for low-loss operation in the high-frequency range. In addition, the cost-effective materials described here (plastic and metal coating material) can be processed using simple processes. The embodiment of the waveguide component described here can therefore be produced at relatively low manufacturing costs.

[0006] Preferably, the plastic comprises polyphenylene sulfide, polyamide, polybutylene terephthalate, and / or polycarbonate. The types of plastic described here ensure good robustness of the interacting metal coating even under extreme temperatures, such as in a temperature range between -40 °C and 130 °C, extreme temperature fluctuations, and resistance to moisture and chemically reactive gases.

[0007] For example, the metal coating applied to and / or above the at least one surface of the waveguide oriented towards the internal volume can have an aluminum mass fraction of at least 90 wt.%. The term "metal coating" can specifically refer to an aluminum coating. Such a high aluminum mass fraction of at least 90 wt.% not only saves on material costs but also generally contributes to improved adhesion of the metal coating to the waveguide.

[0008] Preferably, the metal coating borders a protective layer comprising natural aluminum oxide on its respective side facing the inner volume. In this case, the protective layer prevents further oxidation of the metal coating and / or a chemical reaction between the metal coating and a chemically reactive material in the spatial environment of the waveguide component described herein.

[0009] As an advantageous further development, a buffer layer with a mass fraction of nickel and / or chromium of at least 50 wt.% can be arranged between the metal coating and the adjacent surface of the waveguide. The buffer layer then contributes to improving the adhesion of the metal coating to the associated waveguide.

[0010] Preferably, the buffer layer has a nickel content of between 70 wt.% and 90 wt.% and a chromium content of between 10 wt.% and 30 wt.%. Such a nickel-chromium ratio in the buffer layer significantly improves the adhesion of the metal coating, particularly due to the relatively high aluminum content of the metal coating.

[0011] As a further advantageous development, the metal coating and / or the protective layer can be covered on its respective side facing the inner volume by at least one passivation layer comprising aluminum oxide, aluminum nitride, silver, gold, chromium, and / or nickel. In this case, the at least one passivation layer provides improved robustness of the waveguide section described here against chemically reactive liquids and gases.

[0012] In a further advantageous embodiment of the waveguide component, the one-piece waveguide, two waveguide components of the two-piece waveguide, or all at least three waveguide components of the multi-piece waveguide are machined from at least one block of material, each containing at least 90 wt.% aluminum. The embodiment of the waveguide component described here also exhibits high robustness even at extreme temperatures, particularly in a temperature range between -40 °C and 130 °C, under extreme temperature fluctuations, and in the presence of chemically reactive materials.

[0013] In particular, the waveguide can comprise a first waveguide component and a second waveguide component, wherein the first waveguide component and the second waveguide component are arranged relative to each other without an electrically conductive soldered or glued connection such that a longitudinal axis extending from a first open end of the inner volume to a second open end of the inner volume can be defined, with respect to which the first waveguide component lies on a first side of the longitudinal axis and the second waveguide component lies on a second side of the longitudinal axis pointing away from the first side. Precisely because the waveguide described here, despite its realization from the first waveguide component and the second waveguide component, does not require an electrically conductive soldered or glued connection, the waveguide itself or its metal coating can have a comparatively high mass fraction of aluminum of at least 50 wt.%.The formation of the waveguide from the first waveguide component and the second waveguide component therefore does not preclude the advantageous use of aluminum.

[0014] The aforementioned advantages are also guaranteed with an antenna device that uses such a waveguide section.

[0015] Furthermore, implementing a corresponding manufacturing process for a waveguide component of an antenna device also yields the advantages explained above. It is expressly noted that the manufacturing process can be further developed according to the embodiments of the waveguide component described above. Brief description of the drawings

[0016] Further features and advantages of the present invention are explained below with reference to the figures. They show: Fig. 1 a schematic representation of a first embodiment of the waveguide part; Figs. 2 to 9 schematic representations of further embodiments of the waveguide part; and Fig. 10 a flowchart to explain an embodiment of the manufacturing process for a waveguide part of an antenna device. Embodiments of the invention

[0017] Fig. 1 shows a schematic representation of a first embodiment of the waveguide part.

[0018] The in Fig. 1 The schematically depicted waveguide section has a waveguide 10 which at least partially surrounds an inner volume 12. The inner volume 12 can be understood to be a volume that can be filled with at least one gaseous material, such as, in particular, a volume that can be filled with air. The waveguide 10 of the embodiment shown is shown only as an example. Fig. 1A two-part waveguide 10, comprising a first waveguide component 10a and a second waveguide component 10b. Alternatively, the waveguide 10 can also be a single-part waveguide or a multi-part waveguide with at least three waveguide components.

[0019] The waveguide section can be used to propagate an electromagnetic wave through the inner volume 12, in particular along a longitudinal axis 14 of the inner volume 12, which runs from a first open end of the inner volume 12 to a second open end of the inner volume 12 through the inner volume 12. The propagating electromagnetic wave is accompanied by electric surface currents on at least one surface 16 of the waveguide 10 oriented towards the inner volume 12. The arrows 18 indicate the direction of these currents. Fig. 1A so-called traversal electric wave TE10 is also represented. It is also evident that the traversal electric wave TE10, in a plane of symmetry 20 with respect to which the first waveguide component 10a is arranged in a mirror-symmetrical manner to the second waveguide component 10b, does not trigger any electric surface currents on the at least one surface 16 of the waveguide 10 oriented towards the inner volume 12. Therefore, the first waveguide component 10a and the second waveguide component 10b can also be separate from each other and without an electrically conductive soldered or glued connection.Instead, it is sufficient if the first waveguide component 10a and the second waveguide component 10b are arranged relative to each other without an electrically conductive soldered or glued connection such that the first waveguide component 10a lies on a first side of the longitudinal axis 14 and the second waveguide component 10b lies on a second side of the longitudinal axis 14 directed away from the first side.

[0020] The elimination of the need for an electrically conductive soldered or glued connection between the first waveguide component 10a and the second waveguide component 10b allows the waveguide 10 to be designed with an aluminum content of at least 50 wt.% (weight percent). In particular, the waveguide 10 can have an aluminum content of at least 90 wt.% (weight percent), as well as at least 95 wt.% (weight percent), and specifically at least 99.95 wt.% (weight percent). Aluminum is a comparatively inexpensive and relatively easy-to-machine / formable material for the waveguide 10. The design of the waveguide 10 with an aluminum content of at least 50 wt.% (weight percent) is therefore possible.The -% (weight percent) contributes advantageously to achieving high electrical conductivity of the waveguide section, particularly for electromagnetic waves with frequencies in the radio frequency range, specifically frequencies between 76 GHz (gigahertz) and 81 GHz (gigahertz), making the waveguide section described here advantageously suitable for propagating such electromagnetic waves. Furthermore, the aluminum material exhibits high temperature resistance and good robustness against chemically reactive materials.

[0021] The two-part waveguide 10, or a corresponding one-part waveguide or a corresponding multi-part waveguide with at least three waveguide components, can be formed from at least one block of material with a mass fraction of aluminum of at least 90 wt.% (weight percent), preferably with a mass fraction of aluminum of at least 95 wt.% (weight percent), and in particular with a mass fraction of aluminum of at least 99.95 wt.% (weight percent). The forming of the respective waveguide 10, or its waveguide components 10a and 10b, can be carried out, for example, by milling, punching, and / or punching. Alternatively, the waveguide 10 with a mass fraction of aluminum of at least 50 wt.% (weight percent) can also be manufactured by pressure die casting.However, it is expressly pointed out that the examples listed here for a structuring process or manufacturing process are only to be interpreted as examples.

[0022] Fig. 2 shows a schematic representation of a second embodiment of the waveguide part.

[0023] In contrast to the previously described embodiment, the waveguide part of the Fig. 2A waveguide 10, which is at least partially made of a plastic material. Furthermore, a metal coating 22 with a mass fraction of aluminum of at least 50 wt.% (weight percent) is formed on and / or over at least one surface 16 of the waveguide 10 oriented towards the inner volume 12. Such a high mass fraction of aluminum in the metal coating 22 is possible because, despite the absence of an electrically conductive soldered or adhesive connection between the first waveguide component 10a and the second waveguide component 10b, the propagation of electromagnetic waves along the longitudinal axis 14 of the inner volume 12 is possible without interference. Therefore, when forming the metal coating 22, no consideration needs to be given to the robustness of its at least one material with respect to a no longer required electrically conductive soldered or adhesive connection.

[0024] The metal coating 22, with a mass fraction of aluminum of at least 50 wt.% (weight percent), enables the waveguide section to be well suited for the propagation of electromagnetic waves, in particular electromagnetic waves with frequencies in the radio frequency range, specifically electromagnetic waves with frequencies between 76 GHz (gigahertz) and 81 GHz (gigahertz). It is also noted here that the use of such an aluminum-rich metal coating 22 enables comparatively low-loss propagation of electromagnetic waves through the waveguide section. Preferably, the at least one surface 16 of the waveguide 10 oriented towards the inner volume 12 is (essentially) completely covered by the metal coating 22.

[0025] The metal coating 22 arranged on and / or above the at least one surface 16 of the waveguide 10 oriented towards the inner volume 12 preferably has a mass fraction of aluminum of at least 90 wt.% (weight percent), more preferably a mass fraction of aluminum of at least 95 wt.% (weight percent), and specifically a mass fraction of aluminum of at least 99.95 wt.% (weight percent). The metal coating 22 can therefore also be referred to as an aluminum metal coating. The metal coating 22 can thus be implemented in a cost-optimized manner while still exhibiting high electrical conductivity. Additionally, the waveguide 10 can also be produced cost-effectively from plastic, for example, by injection molding. The waveguide 10, or its waveguide components 10a and 10b, can in particular each be a so-called injection-molded plastic part.

[0026] The plastic used to manufacture the waveguide 10, or its waveguide components 10a and 10b, preferably comprises polyphenylene sulfide (PPS), polyamide (PA), polybutylene terephthalate (PBT), and / or polycarbonate (PC). This allows for the use of comparatively inexpensive materials for the plastic, which also ensure good adhesion of the aluminum-rich metal coating 22 to the waveguide 10. It should also be noted that the plastics mentioned here exhibit good robustness against extreme temperatures and chemically reactive materials (liquids and gases). In particular, polyphenylene sulfide (PPS) has a coefficient of thermal expansion similar to that of aluminum. This also contributes to improving the adhesion of the metal coating 22 to the waveguide 10. If desired, the plastic can also be filled with minerals, glass fibers, and / or glass beads.

[0027] To form the metal coating 22 on and / or above the at least one surface 16 of the waveguide 10 oriented towards the inner volume 12, a PVD process (physical vapor deposition), a sputtering process / cathode sputtering process, such as in particular DC sputtering and / or RF sputtering, an evaporation process, and / or an electroplating process can be carried out. However, the processes listed here for forming the metal coating 22 are not exhaustive. The thickness of the metal coating 22 is preferably between 300 nm (nanometers) and 3000 nm (nanometers).

[0028] Preferably, the metal coating 22 borders a protective layer 24, comprising natural aluminum oxide, on its respective side facing the inner volume 12. The protective layer 24 can, in particular, be (essentially) a natural aluminum oxide layer. The protective layer 24 reliably protects the metal coating 22 from (further) oxidation. The protective layer 24 also ensures a comparatively low dielectric loss during the propagation of electromagnetic waves with frequencies in the radio frequency range, especially electromagnetic waves with frequencies between 76 GHz (gigahertz) and 81 GHz (gigahertz). The protective layer 24 can also be formed by so-called natural oxidation, achieved by briefly exposing the metal coating 22 to oxygen-containing air. This eliminates the need for artificial deposition of the protective layer 24.It is also not necessary to control the thickness of the protective layer 24 during the exposure of the metal coating 22 to oxygen-containing air, as an advantageous thickness of the protective layer 24 is usually established automatically.

[0029] Regarding further features and properties of the waveguide section of the Fig. 2 and its advantages are referred to in the previously described embodiment of the Fig. 1 referred.

[0030] Fig. 3 shows a schematic representation of a third embodiment of the waveguide part.

[0031] The in Fig. 3 The schematically depicted waveguide section, in addition to the previously described embodiment, features the Fig. 2A buffer layer 26 is arranged between the metal coating 22 and the adjacent surface 16 of the waveguide 10. The buffer layer 26 has a mass fraction of nickel and / or chromium of at least 50 wt.% (weight percent). The buffer layer 26 improves the adhesion of the aluminum-rich metal coating 22 to the waveguide 10. In particular, the materials nickel and chromium are especially well suited for improving the adhesion of the aluminum-rich metal coating 22 to the waveguide 10. The buffer layer 26 can therefore also be referred to as an adhesion-promoting layer or adhesion-enhancing layer.

[0032] Preferably, the at least one surface 16 of the waveguide 10 oriented towards the inner volume 12 is (essentially) completely covered by the buffer layer 26, wherein at least one interface of the buffer layer 26 oriented towards the inner volume 12 is covered with the metal coating 22. Preferably, the buffer layer 26 has a mass fraction of nickel and / or chromium of at least 65 wt.% (wt. percent), more preferably a mass fraction of nickel and / or chromium of at least 80 wt.% (wt. percent), and more specifically a mass fraction of nickel and / or chromium of at least 95 wt.% (wt. percent). For example, the buffer layer 26 can be a chromium layer.

[0033] Alternatively, the buffer layer 26 can be a nickel-chromium alloy layer. Preferably, the buffer layer 26 then has a mass fraction of nickel between 70 wt.% and 90 wt.% and a mass fraction of chromium between 10 wt.% and 30 wt.%. In particular, the buffer layer 26 can have a mass fraction of nickel between 75 wt.% and 85 wt.% and a mass fraction of chromium between 15 wt.% and 25 wt.%. In a particularly advantageous embodiment, the buffer layer 26 is a nickel-chromium alloy layer with a mass fraction of nickel between 79 wt.% (weight percent) and 81 wt.% (weight percent) and a mass fraction of chromium between 19 wt.% (weight percent) and 21 wt.% (weight percent).

[0034] The buffer layer 26 can also be formed using a PVD process (physical vapor deposition), a sputtering / spraying process, such as DC sputtering and / or RF sputtering, an evaporation process, and / or an electroplating process. A preferred thickness of the buffer layer 26 is between 10 nm and 300 nm, particularly between 20 nm and 200 nm.

[0035] Regarding further features and properties of the waveguide section of the Fig. 3 and its advantages are referred to in the previously described embodiments of the Fig. 1 and 2 referred.

[0036] Figs. 4 and 5 show schematic representations of one further embodiment of the waveguide part.

[0037] The in the Figs. 4 and 5The schematically depicted waveguide parts differ from the embodiment of the Fig. 3 especially in that its metal coating 22 (see Fig. 4 ) or its protective layer 24 (see Fig. 5 ) on their respective sides facing the internal volume 12, is covered by at least one passivation layer 28. The at least one passivation layer 28 can additionally prevent undesirable (further) oxidation of the metal coating 22 with its mass fraction of aluminum of at least 50 wt.% (weight percent). As in Fig. 4If it is apparent that the protective layer 24 is not required, it may be optional to form it. In particular, at least one interface of the metal coating 22 or the protective layer 24 oriented towards the inner volume 12 may be (essentially) completely covered by the at least one passivation layer 28. The at least one passivation layer 28 preferably comprises aluminum oxide (Al₂O₃), aluminum nitride (AlN), silver, gold, chromium, and / or nickel. Preferably, the at least one passivation layer 28 is an aluminum oxide layer, an aluminum nitride layer, a silver layer, a gold layer, a chromium layer, and / or a nickel-chromium alloy layer, in particular with a mass fraction of nickel between 70 wt.% and 90 wt.% and a mass fraction of chromium between 10 wt.% and 30 wt.%.

[0038] For a layer thickness of the single passivation layer 28 and / or a layer stack of at least two passivation layers 28, values ​​below 200 nm (nanometers) are advantageous. Preferably, the layer thickness of the single passivation layer 28 or the layer stack is between 50 nm (nanometers) and 100 nm (nanometers). It is also noted that, although the at least one passivation layer 28 can also be a silver layer or a gold layer, the use of the comparatively expensive materials silver and gold for the at least one passivation layer 28 can easily be avoided due to the elimination of the need for an electrical contact between the waveguide components 10a and 10b.

[0039] Advantageously, the same deposition technology used to form the metal coating 22 can often be used to form the at least one passivation layer 28. For example, the at least one passivation layer 28 can be formed by means of a PVD process (Physical Vapor Deposition), a sputtering / spraying process, such as DC sputtering and / or RF sputtering, an evaporation process, and / or an electroplating process.In particular, if the at least one passivation layer 28 is / comprises an aluminum oxide layer and / or an aluminum nitride layer, the respective deposition process can transition "fluidly" from the deposition of the metal coating 22 to the deposition of the at least one passivation layer 28 by adding oxygen or nitrogen.

[0040] Regarding further features and properties of the waveguide components of the Figs. 4 and 5 and their advantages are referred to in the previously described embodiments of the Figs. 1 to 3 referred.

[0041] Figs. 6 to 9 show schematic representations of one further embodiment of the waveguide part.

[0042] The waveguide components of the Figs. 6 to 9 differ from the previously described embodiments of the Figs. 2 to 5The only difference is that the first waveguide component 10a and the second waveguide component 10b of the waveguide 10 are spaced so far apart that even after deposition and / or formation of their layers 22 to 28, a gap 30 remains between the coated waveguide components 10a and 10b, extending from the outer environment of the waveguide 10 into the inner volume 12, in which at least one gaseous material, such as air, may be present. The gap 30 has (essentially) no influence on the electromagnetic wave being transmitted. A maximum gap width of the gap 30 is preferably less than 2 mm (millimeters), particularly less than 1 mm (millimeters), and especially less than 0.5 mm (millimeters).

[0043] Regarding further features and properties of the waveguide components of the Figs. 6 to 9 and their advantages are referred to in the previously described embodiments of the Figs. 1 to 5referred.

[0044] All the waveguide parts described above are well suited for use in an antenna device.

[0045] In particular, the waveguide components can also be used in a radar sensor.

[0046] Fig. 10 shows a flowchart to explain one embodiment of the manufacturing process for a waveguide part of an antenna device.

[0047] All the waveguide component embodiments described above can be manufactured using the manufacturing process described below. However, the feasibility of the manufacturing process is not limited to producing only these waveguide components.

[0048] In process step S1 of the manufacturing process, a one-piece, two-piece, or multi-piece waveguide is formed such that the waveguide at least partially surrounds an inner volume. In an advantageous embodiment of the manufacturing process, the waveguide is formed as sub-step S1a of process step S1 with an aluminum mass fraction of at least 50 wt.%. Alternatively, an (optional) process step S2 can be carried out in which a metal coating with an aluminum mass fraction of at least 50 wt.% is formed on and / or over at least one surface of the waveguide oriented towards the inner volume.

[0049] This means that a waveguide component produced using the manufacturing process described here also realizes the advantages explained above.

Claims

1. Waveguide part for an antenna device with a one-piece, two-piece or multi-piece waveguide (10) which at least partially surrounds an inner volume (12); characterized by the fact that the waveguide (10) has a mass fraction of aluminium of at least 50 wt.% and / or a metal coating (22) with a mass fraction of aluminium of at least 50 wt.% is formed on and / or over at least one surface (16) of the waveguide (10) oriented towards the internal volume (12).

2. Waveguide part according to claim 1, wherein the waveguide (10) is at least partially formed from a plastic and has a metal coating (22) arranged on and / or over the at least one surface (16) of the waveguide (10) oriented to the internal volume (12) with a mass fraction of aluminium of at least 50 wt.%.

3. Waveguide part according to claim 2, wherein the plastic comprises polyphenylene sulfide (PPS), polyamide (PA), polybutylene terephthalate (PBT) and / or polycarbonate (PC).

4. Waveguide part according to claim 2 or 3, wherein the metal coating (22) arranged on and / or above the at least one surface (16) of the waveguide (10) oriented towards the internal volume (12) has a mass fraction of aluminium of at least 90 wt.%.

5. Waveguide part according to one of claims 2 to 4, wherein the metal coating (22) is adjacent on its respective side oriented towards the inner volume (12) to a protective layer (24) comprising natural aluminium oxide.

6. Waveguide part according to one of claims 2 to 5, wherein a buffer layer (26) with a mass fraction of nickel and / or chromium of at least 50 wt.% is arranged between the metal coating (22) and the adjacent surface (16) of the waveguide (10).

7. Waveguide part according to claim 6, wherein the buffer layer (26) has a mass fraction of nickel between 70 wt.% and 90 wt.% and a mass fraction of chromium between 10 wt.% and 30 wt.%.

8. Waveguide part according to one of claims 2 to 7, wherein the metal coating (22) and / or the protective layer (24) is covered on its respective side facing the internal volume (12) by at least one passivation layer (28) comprising aluminium oxide, aluminium nitride, silver, gold, chromium and / or nickel.

9. Waveguide part according to claim 1, wherein the one-piece waveguide, two waveguide components (10a, 10b) of the two-piece waveguide (10) or all at least three waveguide components of the multi-piece waveguide are structured from at least one block of material, each with a mass fraction of aluminium of at least 90 wt.%.

10. Waveguide part according to one of the preceding claims, wherein the waveguide (10) comprises a first waveguide component (10a) and a second waveguide component (10b), wherein the first waveguide component (10a) and the second waveguide component (10b) are arranged relative to each other without an electrically conductive soldered or glued connection such that a longitudinal axis (14) extending from a first open end of the inner volume (12) to a second open end of the inner volume (12) through the inner volume (12) can be defined, with respect to which the first waveguide component (10a) lies on a first side of the longitudinal axis (14) and the second waveguide component (10b) lies on a second side of the longitudinal axis (14) directed away from the first side.

11. Antenna device with a waveguide part according to one of the preceding claims.

12. Manufacturing method for a waveguide part of an antenna device comprising the step: forming a one-piece, two-piece or multi-piece waveguide (10) such that the waveguide (10) at least partially surrounds an inner volume (10) (S1); characterized by the fact that the waveguide (10) is formed with a mass fraction of aluminium of at least 50 wt.% (S1a) and / or a metal coating (22) with a mass fraction of aluminium of at least 50 wt.% is formed on and / or over at least one surface (16) of the waveguide (10) oriented towards the internal volume (12) (S2).

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