DE102019203842A1 - Radar antenna structure and manufacturing method for manufacturing a radar antenna structure - Google Patents

Abstract

The present invention relates to a manufacturing method for manufacturing a radar antenna structure, and to a radar antenna structure manufactured according to the manufacturing method. The manufacturing method includes placing one or more mold cores in a casting chamber. The one or more mold cores are made from a first material. The manufacturing method comprises manufacturing a base body of the radar antenna structure by introducing a second material into the casting chamber. The manufacturing method also includes melting out the one or more mold cores. At the time of melting out, the second material has a higher melting point than the first material. By melting out the one or more mold cores, one or more cavities are formed in the base body. The one or more mold cores are shaped such that after the one or more mold cores have melted out, the one or more cavities each have a hollow chamber structure and one or more hollow conductor structures. The hollow chamber structure is designed to couple received radar signals into the one or more waveguide structures.

Description

The present invention relates to a manufacturing method for manufacturing a radar antenna structure, and to a radar antenna structure manufactured according to the manufacturing method.

Radar antennas are used to convert high-frequency energy emitted by a radar transmitter into electromagnetic fields, the power of which is distributed in certain directions by the radar antenna. At the same time, the antennas are also used to receive the echo signals based on the emitted signals. One possible implementation of radar antennas are so-called horn antennas. Horn antennas generally comprise a funnel-like structure (which can approximate the shape of an exponential funnel) and one or more waveguides that are used to feed a signal into the funnel-like structure. In other radar antennas, more complex structures can also be used to feed the signal into the one or more waveguides. These radar antennas are referred to below as cavity antennas. Horn antennas are a special form of cavity antennas.

Horn antennas are manufactured variously in the prior art. So the Scriptures reveal DE 69304983 T2 a microwave antenna molded using plastic injection molding with a metallized surface. The microwave antenna is divided into various sub-assemblies cast in an injection molding process, which are then mechanically connected to form the complex structures of the microwave antenna.

Alternatively, additive manufacturing processes, such as those known from 3D printing, are used in some cases to manufacture radar antennas.

Both approaches have in common that they are time-consuming and expensive and are therefore only suitable to a limited extent for the production of radar antennas in large series, for example in the field of vehicle sensors.

From the pamphlet DE 3820574 A1 It is also known to use lost cores sheathed with elastomer or thermosetting plastic in order to produce hollow plastic bodies. It is also in writing DE 7036315 U presented a reflector for electromagnetic waves based on a galvanized plastic component.

The object according to the invention is to produce a radar antenna structure by means of a production method which enables cost-effective production of the radar antenna structure with complex inner waveguides.

The invention is based on the idea of producing the radar antenna in a primary molding process, such as injection molding, using so-called lost cores (mold cores). One or more mold cores are placed in a casting chamber. A base body for the radar antenna is then manufactured in the casting chamber. In order to obtain a hollow chamber structure (for example a funnel structure) and one or more waveguide structures of the radar antennas, the one or more mold cores are then melted out and removed from the base body. For this it is necessary that at least at the time of melting out the base body has a higher melting point than the one or more mold cores. If the base body is made of an electrically conductive material, no further step is necessary. If this is not the case, a surface of the hollow bodies which form the hollow chamber structure and the one or more hollow conductor structures is further coated by an electrically conductive metallization.

By using lost cores, complex structures, such as the hollow chamber structure and the waveguide structures, can also be produced without the radar antenna structure having to be assembled from different parts or built up additively. This enables the radar antenna structure to be manufactured at low cost.

Embodiments thus create a manufacturing method for manufacturing a radar antenna structure. The manufacturing method includes placing one or more mold cores in a casting chamber. The one or more mold cores are made from a first material. The manufacturing method comprises manufacturing a base body of the radar antenna structure by introducing a second material into the casting chamber. The manufacturing method also includes melting out the one or more mold cores. At the time of melting out, the second material has a higher melting point than the first material. By melting out the one or more mold cores, one or more cavities are formed in the base body. The one or more mold cores are shaped such that after the one or more mold cores have melted out, the one or more cavities each have a hollow chamber structure and one or more hollow conductor structures. The hollow chamber structure is designed to couple received radar signals into the one or more waveguide structures. The hollow chamber structure can be designed as a funnel structure.

In some exemplary embodiments, for example in exemplary embodiments in which the second Material is not itself electrically conductive, the production method further comprises coating a surface of the one or more cavities with an electrically conductive metallization. This enables the one or more cavities to be used as part of a radar antenna, since the electrically conductive surface reflects the radar radiation and guides it along the waveguide. Alternatively, the second material can be an electrically conductive material, so that a surface of the one or more cavities is designed to be electrically conductive.

For example, the surface of the one or more cavities can be metallized by means of a galvanic process. The surface of the one or more cavities can be metallized, for example, by means of electroless electroplating. This enables the surface of the one or more cavities to be metallized even in the case of complex structures.

In at least some exemplary embodiments, the second material is a plastic. For example, the second material can be a thermoplastic plastic. Thermoplastics can easily be used in injection molding processes. Alternatively, the second material can be a thermosetting plastic. Thermosetting plastics have the advantage that after they have hardened they can no longer be deformed by heating or other measures, for example when the one or more mold cores are melted out. Thermosets can also have a lower processing temperature, which can reduce the thermal load on the mold cores and thus the risk of local melting. Melting would lead to deviations in the desired waveguide geometry.

In exemplary embodiments, the base body of the radar antenna structure is designed in one piece. Since the assembly of different components is avoided, the number of manufacturing steps can be reduced.

In some exemplary embodiments, the manufacturing method further comprises manufacturing the one or more mold cores in a casting method or in an additive manufacturing method. These mold cores can then be used in the manufacturing process.

Embodiments also create a radar antenna structure manufactured according to the manufacturing method.

• 1a und 1b zeigen Flussdiagramme von Ausführungsbeispielen eines Herstellungsverfahrens zum Herstellen einer Radarantennenstruktur;
• 2 zeigt eine schematische Darstellung einer Radarantennenstruktur in einer 3D-Ansicht und einer Schnittansicht;
• 3 zeigt ein Flussdiagramm eines weiteren Ausführungsbeispiels eines Herstellungsverfahrens zum Herstellen einer Radarantennenstruktur;
• 4 zeigt ein schematisches Diagramm eines Formkerns;
• 5 zeigt ein schematisches Diagramm einer Platzierung eines Formkerns in einer Gusskammer;
• 6a bis 6c zeigen verschiedene Ausführungsbeispiele von Konzepten zum Entfernen von flüssigen Rückständen eines Formkerns aus einem Grundkörper einer Radarantennenstruktur; und
• 7 zeigt eine weitere Ausführungsform einer Radarantennenstruktur.

Further advantageous configurations are described in more detail below with reference to the exemplary embodiments shown in the drawings, to which exemplary embodiments are generally but not limited as a whole. Show it:

• 1a and 1b show flow charts of exemplary embodiments of a manufacturing method for manufacturing a radar antenna structure;
• 2 shows a schematic representation of a radar antenna structure in a 3D view and a sectional view;
• 3 shows a flow diagram of a further exemplary embodiment of a manufacturing method for manufacturing a radar antenna structure;
• 4th Figure 3 shows a schematic diagram of a mandrel;
• 5 Figure 12 is a schematic diagram of placement of a mandrel in a casting chamber;
• 6a to 6c show various exemplary embodiments of concepts for removing liquid residues of a mold core from a base body of a radar antenna structure; and
• 7th Figure 3 shows another embodiment of a radar antenna structure.

Various embodiments will now be described more fully with reference to the accompanying drawings, in which some embodiments are shown. In the following description of the attached figures, which only show a few exemplary embodiments, the same reference symbols can designate the same or comparable components. Furthermore, summarizing reference symbols can be used for components and objects that appear several times in an exemplary embodiment or in a drawing, but are described jointly with regard to one or more features.

The 1a and 1b show flow diagrams of exemplary embodiments of a manufacturing method for manufacturing a radar antenna structure. The manufacturing process includes placing 120 of one or more mold cores in a casting chamber. The one or more mold cores are made from a first material. The manufacturing method further includes manufacturing 130 a base body of the radar antenna structure by introducing a second material into the casting chamber. The manufacturing method also includes melting out 140 the one or more mold cores. At the time of melting out, the second material has a higher melting point than the first material. By melting out the one or more mold cores one or more formed a plurality of cavities in the base body. The one or more mold cores are shaped such that after the one or more mold cores have melted out, the one or more cavities each have a hollow chamber structure and one or more hollow conductor structures. The hollow chamber structure is designed to couple received radar signals into the one or more waveguide structures. The hollow chamber structure can be designed as a funnel structure.

The manufacturing process is based on inserting one or more mold cores, so-called “lost cores”, made of a first material into a casting chamber and then filling this casting chamber with a second material in order to produce the basic body of the radar antenna structure. The one or more mold cores are made from a first material. For example, the first material can correspond to or comprise a (low-melting point) metal alloy, or the first material can correspond to or comprise a plastic (with a low melting point). For example, the melting point of the first material can be less than 200 ° C. (or less than 150 ° C., less than 100 ° C., less than 80 ° C.). So that the one or more mold cores can be melted out of the base body, the second material from which the base body is made has a higher melting point than the first material at the time of melting out. For example, at the time of melting out, the second material can have a melting point which is at least 20 ° C. (or at least 50 ° C., at least 100 ° C.) above the melting point of the first material.

The melting point of the second material can also be higher than the melting point of the first material when the base body is being produced, for example if the second material is a thermoplastic. Thermoplastic plastics are plastics that can be reversibly deformed within a certain temperature range. Alternatively, the melting point of the second material after the production of the base body can be higher than before the start of production, for example if the second material is a thermosetting plastic. Thermosetting plastics are plastics which, after hardening, can no longer be deformed by heating or other measures. Since thermosetting plastics no longer have a melting point after curing but go into pyrolysis, the melting point of the thermosetting material in the sense of this application is to be regarded as higher than the melting point of the first material if the first material melts at a temperature at which the second material is Material not (yet) decomposed pyrolytically. In other words, for the purposes of this application, the melting temperature for thermosetting plastics is to be taken as the temperature at which a bond break within large molecules is forced into smaller molecules in the second material.

In at least some exemplary embodiments, as in FIG 1b is shown, also a manufacturing 110 the one or more mold cores in a casting process (such as an injection molding process) or in an additive manufacturing process (such as in a 3D printing process such as stereolithography or melt layering).

The one or more mold cores are shaped such that after the one or more mold cores have melted out, the one or more cavities each have a hollow chamber structure and one or more hollow conductor structures. For example, any mold core, as in 4th shown, may be formed in one piece, but comprise several subsections which, after melting out, form the hollow chamber structure and the one or more hollow conductor structures. The mold core can have a partial section 42a include the hollow chamber structure 42 (for example as a collecting funnel of a funnel structure), and one or more substructures 44a ; 46a that contain the one or more waveguide structures 44 ; 46 (e.g. as channels). This can be a cavity 40 through the hollow chamber structure 42 and the one or more waveguide structures 44 ; 46 are formed. The hollow chamber structure 42 forms together with the one or more waveguide structures 44 ; 46 a coherent waveguide 40 . In other words, each cavity of the one or more cavities forms a coherent waveguide. This waveguide can go through those sections 40a of the mold core are formed during the introduction of the second material in the casting chamber 20th are located. In addition, every mold core can have positioning and fixing aids 410 ; 420 ; 430 include with which the mold core in or on the casting chamber 20th is attached.

In at least some exemplary embodiments, the one or more mold cores before the introduction of the second material can be larger than the one or more cavities that arise after the one or more mold cores are melted out. This can be due to the fact that the one or more mold cores can already be deformed when the second material is introduced into the casting chamber due to heat from the second material, and can thereby be compressed, for example, by the second material. By producing a series of prototypes, it is possible to find out experimentally the dimensions with which a mold core can be shaped in order to achieve a desired shape of a cavity.

The manufacturing method further includes manufacturing 130 a base body of the radar antenna structure by introducing the second material into the casting chamber. For example, the second material can be liquefied and introduced into the casting chamber in a liquid state. The second material can be a plastic, for example a thermoplastic plastic or a thermosetting plastic (for example a cured synthetic resin). If the second material is a thermoplastic synthetic material, the second material can be melted and filled into the casting chamber in the melted state. If the second material is a thermosetting plastic, the second material can be filled into the casting chamber in liquid form (for example melted or in a solution) and cured there, for example thermally hardened or hardened by a catalyst or hardener. For example, when it is introduced into the casting chamber, the second material can consist of several components that are connected during the manufacture of the base body, for example by hardening the second material. In other words, the manufacturing method can further include hardening of the second material, for example if the second material is a thermosetting plastic.

In at least some exemplary embodiments, the base body of the radar antenna structure can be designed in one piece. In other words, the base body cannot consist of several layers that are connected mechanically or by a chemical process. Thus, the base body can comprise at least one cavity (for example a plurality of cavities) which comprises a hollow chamber structure, for example a funnel structure of a horn antenna, and one or more waveguide structures (for example one or more feed channels of the horn antenna). The hollow chamber structure can be designed to couple received radar signals into the one or more waveguide structures. A waveguide structure of the one or more waveguide structures can be defined as a channel-like structure with an elongated extension and an essentially constant cross section. The cross-section can be designed, for example, round or rectangular. A waveguide structure can have a course that is not necessarily straight, i.e. a course of the waveguide structure can have at least one bend, wherein the bend can have an angle of approximately 45 ° or 90 °. Each waveguide structure can also include bends in several directions and orientation planes. In this case, after the one or more mold cores have melted out, a cavity can be accessible (open) on at least two different sides of the base body. Thus, the base body can have a first opening for each cavity on a first side, on which the cavity structure of the cavity is arranged. The base body can have one or more second openings on at least one second side different from the first, via which the one or more waveguide structures of the cavity are accessible.

The manufacturing method also includes melting out 140 the one or more mold cores (after manufacturing the base body). To melt out 140 the one or more mold cores, the base body with the one or more mold cores can be heated, for example in an immersion bath or by a heater that at least partially envelops the base body with the mold cores. In the 6a to 6c , which are described in more detail later, several variants are shown. For example, the base body with the one or more mold cores, as in FIG 6a shown in a heated immersion bath 610a be heated to melt the one or more mold cores. In addition, the base body can be rotated in the immersion bath, so that the melted first material is guided out of the base body through the one or more waveguide structures (or through the hollow chamber structure).

Alternatively, the base body with the one or more mold cores can be heated outside of a liquid bath. For each cavity, an overpressure p can be generated at an opening in the base body, so that the molten first material is pressed out of the cavity by the overpressure, for example into a collecting tray 620b . For example, as in 6b As shown, the overpressure can be generated at the opening of the hollow chamber structure / funnel structure 42 and the molten material can flow through the one or more hollow conductors 44 ; 46 in the drip tray 620b be pressed. Alternatively, the overpressure can be generated at the openings to the one or more waveguide structures.

Alternatively, a negative pressure can be generated at at least one of the openings in the base body, so that the melted first material is sucked out of the cavity by the negative pressure. For example, as in 6c shown, the negative pressure at the openings to the one or more waveguide structures 44 ; 46 generated, for example in the drip tray 620c , and the melted material of the one or more mold cores can by the negative pressure from the cavity into the collecting tray 620c be sucked.

By melting out the one or more mold cores, one or more cavities are formed in the base body. In other words, the shape of the one or more cavities essentially corresponds to the shape of at least one Part of the mold cores, which is arranged in the casting chamber.

In order to serve as a radar antenna, the surface of the hollow chamber structure and the one or more hollow conductor structures are electrically conductive, so that the radar radiation is reflected on the surface. For example, the second material can be an electrically conductive material, so that a surface of the one or more cavities is designed to be electrically conductive. For this purpose, the second material can be a metal, for example. Alternatively, the surface of the one or more cavities can be metallized after the production of the base body. In other words, the procedure as in 1b shown, furthermore a coating 150 a surface of the one or more cavities 40 comprise by an electrically conductive metallization. For example, at least 95% (or at least 98%, at least 99%, or 100%) of the surface of each cavity can be metallized. For this purpose, for example, the surface of the one or more cavities 40 be metallized by means of a galvanic process. As in 3 Reference number 350 shown, for example, current can be passed through an electrolytic bath. The metal that is to be applied (e.g. copper) can be located on an anode, and the base body can be located on the cathode (e.g. if the second material is a metal). If the second material is plastic, so-called plastic electroplating can be used. For example, the surface of the one or more cavities can be metallized by means of electroless (no external current) electroplating. However, other plastic metallization processes can also be used, such as physical vapor deposition (such as cathode sputtering or thermal evaporation) or chemical vapor deposition.

In at least some exemplary embodiments, the result of the production method is a radar antenna structure, for example a radar antenna, which is provided for connection to a radar transceiver. The one or more cavities can each form a cavity antenna, for example a horn antenna, with the associated waveguide structure of the radar antenna. In other words, the radar antenna structure or the radar antenna can comprise a plurality of cavity antennas, for example a so-called antenna array (a regular arrangement of antennas). The one or more cavity antennas that are formed by the one or more cavities can be connected to the radar transceiver via the one or more waveguide structures. For example, the radar antenna structure or radar antenna can be a microwave antenna, that is to say, due to its dimensions, can be provided for the transmission and reception of signals in the microwave range.

In an exemplary embodiment, the first side of the main body can define a width and length of the radar antenna, and a further side that runs orthogonally to the first side can define the height of the radar antenna. The height and width of the radar antenna can each be at least twice as large (or at least three times as large, at least four times as large) as the height of the radar antenna. For example, in an automotive application, for example, the radar antenna can have a height of approximately 20 mm and a width and length of approximately 100 mm. A semicircular side of the antenna would also be conceivable to allow the waveguides to emit and receive in a wider angular band.

The manufacturing method can also include further steps. This includes various cleaning steps that take place between or after the above. Steps can be carried out to prepare the one or more mold cores or the base body for the next step in each case or to complete the manufacturing process.

More details and aspects of the manufacturing process and / or the radar antenna structure are cited in connection with the concept or examples that are described before or after. The manufacturing method and / or the radar antenna structure may include one or more additional optional features that correspond to one or more aspects of the proposed concept or the described examples, as described before or after.

At least some exemplary embodiments deal with an adaptation of the fusible core technology for the production of very fine three-dimensional radar antennas in combination with the selection of suitable materials for the subsequent surface coating. This enables a large-scale production process for a 3D radar antenna (such as the radar antenna structure).

A three-dimensional radar antenna, as exemplified in 2 can be seen, is generally composed of several independent conductors. A conductor contains (or consists of) any complex collection funnel (such as the hollow chamber structure) and a single or multiple branched channel (such as the one or more hollow conductor structures). The conductor geometries create a hollow structure (such as the one or more cavities) with various undercuts and very fine structures. In addition to the complex geometry, there is a requirement for an electrically conductive surface of the conductor. The The hollow structure itself (channels and collecting funnels) can be completely filled with a dielectric, preferably air, and should not have any barriers.

2 shows a schematic illustration of a radar antenna structure in a 3D view and a sectional view, for example an exemplary illustration of a 3D radar antenna. 2 shows a radar antenna structure 200 with a base body 30th and a plurality of hollow structures 40 (Cavities) that have an electrically conductive surface. The hollow structures include hollow chamber structures en42 and hollow conductor structures 44 . The basic body of the radar antenna structure 200 is made from a solid material. The left side of the 2 , Reference numbers 210 , shows a 3D view, the right side of the 2 , Reference numbers 220 , shows a sectional view of a single hollow structure (cavity) 40 . In order to get an idea of the dimensions of the individual elements, measurements of a test radar antenna structure are mentioned below. However, these represent only an exemplary embodiment. In one example, the collecting funnel can have a diameter of approximately 12 mm at its opening, the individual waveguides can have a height of approximately 1.5 mm, the common section of the Both waveguide, which connects to the funnel, can be about 3 mm wide, which can roughly correspond to the length of the adjoining transverse section of the waveguide.

In exemplary embodiments of the invention, a fusible core technology with subsequent surface coating is used in order to enable a cost-effective production of radar antenna structures suitable for large-scale production.

1. 1. (Spritz-)Gießen des verlorenen Kerns (mit der Form der „Hohlleiterstruktur“ in 2) aus einem Material (etwa dem ersten Material) mit geringerer Schmelztemperatur als das Antennenmaterial (etwa dem zweiten Material), welches im zweiten (Spritz-)Gießprozess eingesetzt wird. Hierbei kann es sich etwa um eine niedrigschmelzende Metalllegierung oder einen Kunststoff mit niedrigem Schmelzpunkt handeln.
2. 2. Umspritzen oder umgießen des Kerns mit Kunststoff (etwa durch Einbringen des zweiten Materials in die Gusskammer). Dieses Material bildet das „Vollmaterial“ aus 2.
3. 3. Ausschmelzen des Kerns (etwa der ein oder mehreren Formkerne) in einem Tauchbad mit einer Temperatur oberhalb der Schmelztemperatur des Kernmaterials und unterhalb der Temperatur des Antennenmaterials (aus Schritt 2).
4. 4. Oberflächenbeschichtung der Antenne mit elektrisch leitfähiger Schicht, etwa in einem Tauchprozess, um die gesamte Hohlstruktur beschichten zu können.

In some exemplary embodiments, the manufacturing process includes the following points:

1. 1. (Injection) casting of the lost core (with the shape of the "waveguide structure" in 2 ) made of a material (such as the first material) with a lower melting temperature than the antenna material (such as the second material), which is used in the second (injection) molding process. This can be a low-melting metal alloy or a plastic with a low melting point.
2. 2. Overmoulding or casting around the core with plastic (for example by introducing the second material into the casting chamber). This material forms the "solid material" 2 .
3. 3. Melting out the core (for example the one or more mold cores) in an immersion bath at a temperature above the melting temperature of the core material and below the temperature of the antenna material (from step 2 ).
4. 4. Surface coating of the antenna with an electrically conductive layer, for example in a dipping process, in order to be able to coat the entire hollow structure.

Doing so can step 1 can be omitted if the lost core is already available. step 4th can be omitted if the antenna material itself is conductive.

3 FIG. 3 shows a flow diagram of a corresponding exemplary embodiment of a manufacturing method for manufacturing a radar antenna structure. 3 Reference number 310 shows a cast core 10 (for example a mold core of the one or more mold cores). This is in 3 Reference number 320 in a casting chamber 20th used. In 3 Reference number 330 becomes the core 10 encased with the antenna material, so that a base body 20th the radar antenna structure is formed, which is the core 10 includes. In 3 Reference number 340 the antenna is demolded in 3 Reference number 350 the core is melted out of the base body in a heated immersion bath. In 3 Reference number 360 becomes the surface of a cavity 40 by melting out the core 10 arose, coated by means of electroplating. In 3 Reference number 370 is the manufactured radar antenna structure 300 shown having a base body 30th with a cavity 40 includes. The cavity here comprises a hollow chamber structure 42 , which is designed as a funnel structure, and two waveguide structures 44 and 46 that with the hollow chamber structure 42 are connected. The surface 48 of the cavity 40 is coated by a metallization.

The 4th and 5 deal with the handling and fixation of the lost nuclei. A feature of the waveguide of the radar antenna is the two-sided contact with the environment. This is due to the fact that the radar waves are conducted via the collecting funnel (the hollow chamber structure) on the upper side (the first side) into the waveguide and there via the branched channels (the one or more waveguide structures) to the sensors on the lower side (the second Side). This makes it possible to position and fix the insert cores in the tool using positioning aids that are already cast on. 4th Figure 3 shows a schematic diagram of a mandrel 10 . The mold core is made in one piece, but has several sections. The mold core thus comprises a first section 42a , whose shape is the hollow chamber structure 42 corresponds to one or more subsections 44a ; 46a , the shape of which corresponds to the one or more waveguides 44 ; 46 as well as positioning and fixing aids 410 ; 420 and 430 . The combined forms of the subsections 40a later form the cavity in the casting chamber 40 . The fixation aids 410 to 430 are later usually not arranged in the casting chamber, but are designed to accommodate the subsections 40a to be fixed within the casting chamber, as in 5 is shown. 5 Figure 12 shows a schematic diagram of a placement of a mandrel 10 in a casting chamber 20th . With the positioning and fixing aids 410 to 430 becomes the mold core 10 in the casting chamber 20th fixed and positioned.

1. 1. Drehen der Radarantenne während des Ausschmelzprozesses im Tauchbad: Wie in 6a gezeigt ist kann der Grundkörper einer Radarantennenstruktur 600a während des Aufschmelzens des ersten Materials in einem Tauchbad 610a gedreht werden, so dass das geschmolzene Material durch das Drehen und dadurch, dass das erste Material schwerer ist als die Tauchflüssigkeit, durch die Schwerkraft über die Hohlleiterstrukturen aus dem Grundkörper ausfließen kann und sich an dem Boden des Tauchbads 610a ansammelt.
2. 2. Beaufschlagung der Hohleiterstruktur mit einseitigem Überdruck während der Erwärmung: Wie in 6b gezeigt ist kann die Hohlleiterstruktur (der Hohlraum) einer Radarantennenstruktur 600b einseitig, etwa an der Öffnung zu der Hohlkammerstruktur 42 hin, während des Ausschmelzens des Kerns mit Überdruck p beaufschlagt werden, so dass das geschmolzene Material durch den Überdruck aus der Hohlleiterstruktur gepresst wird, etwa über die ein oder mehreren Hohlleiterstrukturen 44; 46, und in einer Auffangwanne 620b aufgefangen werden kann. Dabei kann die Auffangwanne 620b ebenfalls abgedichtet sein.
3. 3. Beaufschlagung der Hohleiterstruktur mit einseitigem Unterdruck während der Erwärmung: Wie in 6c gezeigt ist kann die Hohlleiterstruktur (der Hohlraum) einer Radarantennenstruktur 600c einseitig, etwa an der Öffnung zu den ein oder mehreren Hohlleiterstrukturen 44; 46 hin, während des Ausschmelzens des Kerns mit Unterdruck p beaufschlagt werden, so dass das geschmolzene Material durch den Unterdruck aus der Hohlleiterstruktur gesaugt wird, etwa über die ein oder mehreren Hohlleiterstrukturen 46, und in einer Auffangwanne 620c aufgefangen werden kann. Dabei kann der Unterdruck in der Auffangwanne 620c erzeugt werden.

Möglich ist auch eine Kombination von Überdruck auf der einen Seite und von Unterdruck auf der anderen Seite. 6a to 6c show various exemplary embodiments of concepts for removing liquid residues of a mold core from a base body of a radar antenna structure. To metallize the waveguide structure, a complete melting of the core can be advantageous or essential. To make this possible, several auxiliary measures are conceivable:

1. 1. Rotating the radar antenna during the melting process in the immersion bath: As in 6a the base body of a radar antenna structure can be shown 600a during the melting of the first material in an immersion bath 610a are rotated, so that the molten material by rotating and because the first material is heavier than the immersion liquid, by gravity can flow out of the base body via the waveguide structures and settle on the bottom of the immersion bath 610a accumulates.
2. 2. Application of one-sided overpressure to the waveguide structure during heating: As in 6b the waveguide structure (the cavity) of a radar antenna structure is shown 600b on one side, for example at the opening to the hollow chamber structure 42 while the core is being melted out, overpressure p is applied so that the molten material is pressed out of the waveguide structure by the overpressure, for example over the one or more waveguide structures 44 ; 46 , and in a drip tray 620b can be caught. The drip pan 620b also be sealed.
3. 3. Application of the hollow conductor structure with one-sided negative pressure during heating: As in 6c the waveguide structure (the cavity) of a radar antenna structure is shown 600c on one side, for example at the opening to the one or more waveguide structures 44 ; 46 be applied during the melting of the core with negative pressure p, so that the molten material is sucked out of the waveguide structure by the negative pressure, for example via the one or more waveguide structures 46 , and in a drip tray 620c can be caught. The negative pressure in the drip tray 620c be generated.

A combination of positive pressure on one side and negative pressure on the other is also possible.

7th Figure 3 shows another embodiment of a radar antenna structure 700 how it can be produced according to the manufacturing process presented. 7th shows a basic body 30th the radar antenna structure with a cavity, which is a hollow chamber structure 42 and approaches of waveguides 44 includes. The hollow chamber structure is not designed in the shape of a funnel, but has a more complex geometry, which is designed to couple received radar signals into the one or more waveguide structures.

List of reference symbols

10

Mold core

20th

Casting chamber

30th

Base body

40

cavity

40a

Section of a mold core with the shape of a cavity

42

Hollow chamber structure

42a

Section of a mold core with the shape of a hollow chamber structure

44, 46

Waveguide structure

44a, 46a

Section of a mold core with the shape of a waveguide structure

48

Surface metallization

110

Manufacture of one or more mold cores

120

Placing one or more mold cores in the casting chamber

130

Manufacture of a basic body

140

Melting out the one or more mold cores

150

Coating a surface of one or more cavities

200

Radar antenna structure, radar antenna

210

3D view

220

Sectional view

300

Radar antenna structure, radar antenna

310-370

Steps of an exemplary manufacturing process

410-430

Positioning and fixing aids

600a - c

Radar antenna structure, radar antenna

610a

Immersion bath

620b, 620c

Drip pan

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 69304983 T2 [0003]
• DE 3820574 A1 [0006]
• DE 7036315 U [0006]

Claims (12)

A manufacturing method for manufacturing a radar antenna structure (200; 300; 600a; 600b; 600c; 700), the manufacturing method comprising: Placing (120) one or more mold cores (10) in a casting chamber (20), wherein the one or more mold cores (10) are made from a first material; Production (130) of a base body (30) of the radar antenna structure by introducing a second material into the casting chamber (20); and Melting out (140) the one or more mold cores (10), wherein the second material at the time of melting out has a higher melting point than the first material, one or more cavities (40) being formed in the base body (30) by melting out the one or more mold cores (10), wherein the one or more mold cores (10) are shaped such that after the one or more mold cores (10) have melted out, the one or more cavities (40) each have a hollow chamber structure (42) and one or more waveguide structures (44; 46) , wherein the hollow chamber structure is designed to couple received radar signals into the one or more waveguide structures. The manufacturing process according to Claim 1 , further comprising coating (150) a surface of the one or more cavities (40) by an electrically conductive metallization. The manufacturing process according to Claim 2 wherein the surface of the one or more cavities (40) is metallized by means of a galvanic process. The manufacturing process according to Claim 3 , the surface of the one or more cavities being metallized by means of electroless electroplating. The manufacturing method according to one of the Claims 2 to 4th wherein the second material is a plastic. The manufacturing process according to Claim 5 wherein the second material is a thermoplastic plastic. The manufacturing process according to Claim 5 wherein the second material is a thermosetting plastic. The manufacturing process according to Claim 1 wherein the second material is an electrically conductive material, so that a surface of the one or more cavities is electrically conductive. The manufacturing method according to one of the preceding claims, wherein the base body of the radar antenna structure is formed in one piece. The manufacturing method according to one of the preceding claims, wherein the hollow chamber structure (42) of the one or more hollow spaces is each designed as a funnel structure. The manufacturing method according to one of the preceding claims, further comprising manufacturing (110) the one or more mold cores in a casting process or in an additive manufacturing process. Radar antenna structure (200; 300; 600a; 600b; 600c; 700) produced by the production method according to one of the preceding claims.

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