EP3262713B1 - Reflector with an electronic circuit and antenna device comprising a reflector - Google Patents

Description

The present invention relates to a reflector with an electronic circuit which can be used, for example, for reflecting an incident electromagnetic wave, and to an antenna device. The present invention also relates to a dual reflector system with active electronics integrated into the main reflector.

There are decoupled, non-integrated solutions in which the directional antenna, data processing and radio front end (i.e. electronic circuits) represent independent modules that are connected to one another. This is done by means of coaxial connections, conductor tracks from the outputs of the electronic components, such as amplifiers, transitions from conductor tracks to waveguides, bond wire connections or the like. Disadvantages here are the physical size of the overall system as well as losses in terms of weight and efficiency of the antenna system, such as losses in the transition from electronics to antenna, adjustment losses, etc.

Integrated solutions that implement the electronics of the data processing, the radio front end and the transmitting or receiving antenna (feed antenna) together on a circuit board are used in so-called PIFA (Planar Inverted-F Antenna) or patch antennas based on circuit boards or on-chip antennas that radiate out of a chip housing are used. These antennas have a wide radiation, do not develop a high directional effect and are therefore unsuitable for radio relay applications. Phased-array antennas also use the principle of integrated electronics in combination with radiating antenna elements on a circuit board, but do not use reflector components to increase the directional effect, but use the combined radiation of many active antenna elements (e.g. patch antennas on the circuit board) to achieve a directional effect. This is associated with complicated active electronics, phase shifters and a complex control network of the individual antenna elements.

Another approach uses so-called reflect array (i.e. an array of reflector elements) circuit boards with layers of integrated solar cells that are used for energy generation, e.g. on a satellite. This is done on the basis of passive electronics.

Fig. 14 FIG. 11 shows a schematic illustration of a reflect array 102 which comprises a substrate 104 and a multiplicity of scattering elements 106. A feed antenna 108 arranged at a distance from the reflect array 102 can emit a radio signal in the direction of the reflect array 102, the radio signal being reflected by the reflect array 102.

The main reflector (reflect array 102) and optional sub-reflectors (further reflectors) can be implemented on the basis of printed circuit boards with individual reflective metallic elements on a substrate with an underlying metallic ground plane, i.e. reflect arrays. The reflective elements on the printed circuit boards are used to impress a desired phase function on the incident radiation, in order to simulate the function of a physically curved main or subreflector.

In " Design of Millimeter Wave Microstrip Reflectarrays "(David M. Pozar et al., IEEE Transactions on Antennas and Propagation, Vol. 45, No. 2, February 1997 ) a modeling of a reflect array is described, which is designed for the entire wave.

In " A Dual Planar Reflectarray With Synthesized Phase and Amplitude Distribution (Ralf Leberer et al. IEEE Transactions on Antennas and Propagation, Vol 53, No. 11 November 2005 ) describes a quasi-planar reflector arrangement in which any phase and amplitude distribution can be set.

In WO 2005/031921 A1 a reflector antenna for bundling radar waves for distance sensors is disclosed, which optionally has one or more subreflectors.

Accordingly, a concept for antenna reflectors and / or antenna devices that enables efficient operation of the same would be desirable.

The object of the present invention is therefore to create a reflector and an antenna device which enable efficient operation and a compact, possibly lighter design of the same.

This object is achieved by the subject matter of the independent patent claim. According to this, an antenna device comprises a reflector which has: a substrate and a multiplicity of reflector structures which are arranged on or in the substrate. The reflector structures are designed to reflect an incident electromagnetic wave. An electronic circuit is arranged on or in the substrate and is designed to control an antenna when the antenna is connected to the electronic circuit. The advantage of this embodiment is that power losses between data processing and a radio front end can be small, for example if the electronic circuit includes the data processing and the radio front end. The reflector can be compact, i.e. that is, having a small installation space and, if necessary, can be implemented with a low weight. The antenna device further comprises: an antenna arranged on the substrate; and a subreflector which is designed to reflect the electromagnetic wave emitted by the antenna at least partially in the direction of the plurality of reflector structures, so that the electromagnetic wave reflected by the subreflector is directed in the direction of the plurality of reflector structures and is reflected again by them. The antenna arranged on or in the substrate has the advantage that power losses between the electronic circuit and the antenna are also reduced, so that even more efficient operation of the reflector is made possible. Another advantage is that a compact assembly can be realized in which the reflector and antenna are designed adjacent to one another or even integrated. The advantage of the subreflector is that an integrated design of the antenna and / or efficient operation of the antenna device is made possible. The antenna is connected to the electronic antenna control circuit and is designed to generate the electromagnetic wave based on a control of the electronic antenna control circuit and to transmit it in a direction of the subreflector. The plurality of reflector structures are arranged in at least two mutually different substrate planes which are arranged parallel to a substrate surface which is arranged facing a direction in which the electromagnetic wave is reflected.

According to one exemplary embodiment, the plurality of reflector structures is designed to reflect the incident electromagnetic wave in such a way that the reflected electromagnetic wave is bundled as a result of the reflection at the plurality of reflector structures. The advantage of this is that a directional effect (ie collimated or at least less scattered electromagnetic wave) of the radio signal to be transmitted is obtained by means of the reflector structures, so that a low transmission power signal transmission required and / or having a long transmission path is made possible by means of the reflector, which leads to a further increased operating efficiency.

According to a further exemplary embodiment, at least one reflector structure of the plurality of reflector structures comprises a plurality (two or more) of dipole structures. This has the advantage that, based on the reflector structures and in connection with the electronic circuit, a plurality of transmission channels can be used or implemented is, for example, a transmission channel per dipole structure, a reception channel per dipole structure and / or a simultaneous transmission operation and reception operation of the electronic circuit and / or a connected antenna.

According to a further exemplary embodiment, the reflector comprises a radome structure which is arranged with respect to the plurality of reflector structures and is designed to at least partially reduce a mechanical or chemical influence of an environment of the plurality of reflector structures on the plurality of reflector structures. The radome structure comprises, at least in some areas, an electrically conductive structure which is designed to reflect the electromagnetic wave, the electrically conductive structure being arranged with respect to the plurality of reflector structures in such a way that the electromagnetic wave reflected by the electrically conductive structure in the direction of the plurality of Reflector structures are directed and reflected again by these. In simple terms, the electrically conductive structure can be arranged as a sub-reflector with respect to a reflector used as the main reflector. The advantage of this exemplary embodiment is that the reflector is less sensitive to external influences and that the reflector can be used as a Cassegrain reflector structure or as a Gregorian reflector structure.

According to one embodiment, the reflector structures and the sub-reflector have a Cassegrain configuration or a Gregorian configuration. The advantage here is that a high directivity of the antenna device can be obtained, so that a low transmission power is required and / or a high transmission range is obtained. According to a further exemplary embodiment, the antenna is designed as a surface-mounted component (Surface Mounted Device - SMD). The advantage of this is that the antenna device as an overall structure has a high functional integration density and the antenna device can be designed with a small installation space and / or a low weight.

According to a further exemplary embodiment, an axial relative position of the sub-reflector with respect to the reflector can be changed along an axial direction parallel to a surface normal of the substrate. It is advantageous here that a radiation characteristic of the antenna device, for example a focusing of the incident electromagnetic wave, can be set.

According to a further exemplary embodiment, a lateral relative position of the subreflector with respect to the reflector can be changed along a lateral direction perpendicular to a surface normal of the substrate or an inclination of the main reflector or subreflector with respect to a surface of the substrate of the reflector. The advantage of this exemplary embodiment is that a radiation direction of the antenna device can be changed without changing a phase function of the multiplicity of reflector structures.

According to a further embodiment, the antenna comprises a plurality of antenna elements, wherein a first subset of the antenna elements is designed to generate the electromagnetic wave with a first polarization direction and wherein a second subset of the antenna elements is designed to transmit the electromagnetic wave with a second polarization direction produce. A first subset of the plurality of reflector structures is designed to reflect the electromagnetic wave with a first degree of reflection when the electromagnetic wave has the first polarization direction and to reflect with a second degree of reflection when the electromagnetic wave has the second polarization. A second subset of the plurality of reflector structures is designed to reflect the electromagnetic wave with a third degree of reflection when the electromagnetic wave has the second polarization direction and to reflect with a fourth degree of reflection when the electromagnetic wave has the first polarization. The first reflectance and the third reflectance have a larger value than the second reflectance and the fourth reflectance. This has the advantage that signals that differ from one another and have polarizations that differ from one another can be transmitted and / or received at the same time, so that a transmission efficiency of the antenna device is high.

According to one embodiment, the antenna is designed to guide an electromagnetic wave transmitted in the direction of the antenna device and received by the antenna device to the electrical circuit or a further electrical circuit. The advantage here is that a transmission function, a reception function and the generation of the electromagnetic wave can be carried out in an integrated manner as a function of a device.

According to a further exemplary embodiment, the antenna device comprises a plurality of antennas and a plurality of subreflectors, each subreflector being assigned to an antenna. It is advantageous here that the reflector can be arranged jointly with respect to the plurality of antennas and the plurality of subreflectors, so that a high degree of compactness of a multiple antenna device is obtained.

Further advantageous embodiments are the subject of the dependent claims.

Fig. 1

ein schematisches Blockschaltbild eines Reflektors gemäß einem Ausführungsbeispiel;

Fig. 2

eine schematische Seitenschnittansicht eines Reflektors mit einem Substrat, das eine mehrlagige Platine umfasst gemäß einem Ausführungsbeispiel;

Fig. 3a

eine schematische Aufsicht auf eine Reflektorstruktur, die als Rechteck ausgeführt ist gemäß einem Ausführungsbeispiel;

Fig. 3b

eine schematische Aufsicht auf eine Reflektorstruktur, die als Ellipse ausgeführt ist gemäß einem Ausführungsbeispiel;

Fig. 3c

eine schematische Aufsicht auf eine Reflektorstruktur, die als Kombination zweier Dipolstrukturen ausgeführt ist gemäß einem Ausführungsbeispiel;

Fig. 3d

eine schematische Aufsicht einer Reflektorstruktur, die drei jeweils mit einem Winkel zueinander angeordnete Dipolstrukturen umfasst gemäß einem Ausführungsbeispiel;

Fig. 4

eine schematische Ansicht eines Reflektors, der gegenüber dem Reflektor aus Fig. 1 um ein Gehäuseteil erweitert ist gemäß einem Ausführungsbeispiel;

Fig. 5

eine schematische Seitenschnittansicht eines Reflektors, bei dem das Substrat Durchkontaktierungen umfasst gemäß einem Ausführungsbeispiel;

Fig. 6

ein schematisches Blockschaltbild einer Antennenvorrichtung einen Reflektor und eine Antenne gemäß einem Ausführungsbeispiel;

Fig. 7

ein schematisches Blockschaltbild einer Antennenvorrichtung, bei der eine Vielzahl von Reflektorstrukturen gem. Fig. 3c an dem Substrat gemäß einem Ausführungsbeispiel;

Fig. 8

ein schematisches Blockschaltbild einer Antennenvorrichtung, die eine Hornantenne umfasst gemäß einem Ausführungsbeispiel;

Fig. 9

ein schematisches Blockschaltbild einer Antennenvorrichtung, bei der ein Substrat eine unebene Form aufweist gemäß einem Ausführungsbeispiel;

Fig. 10

eine schematische Aufsicht auf ein Substrat, an dem eine Vielzahl von Reflektorstrukturen und elektrische Teilschaltungen angeordnet sind gemäß einem Ausführungsbeispiel;

Fig. 11

eine schematische Seitenansicht des Reflektors aus Fig. 1 zur Verdeutlichung der Funktion der aufgeprägten Phasenfunktion gemäß einem Ausführungsbeispiel;

Fig. 12

eine schematische Seitenansicht einer Antennenvorrichtung, die als gefaltete Reflectarray-Antenne ausgeführt ist gemäß einem Ausführungsbeispiel;

Fig. 13

eine schematische Ansicht einer Antennenvorrichtung, die die Hornantenne und den Reflektor gem. Fig. 1 umfasst gemäß einem Ausführungsbeispiel; und

Fig. 14

eine schematische Darstellung eines Reflectarrays gemäß dem Stand der Technik.

Preferred embodiments of the present invention are explained below with reference to the accompanying drawings. Show it:

Fig. 1

a schematic block diagram of a reflector according to an embodiment;

Fig. 2

a schematic side sectional view of a reflector with a substrate comprising a multi-layer circuit board according to an embodiment;

Fig. 3a

a schematic plan view of a reflector structure, which is designed as a rectangle according to an embodiment;

Figure 3b

a schematic plan view of a reflector structure, which is designed as an ellipse according to an embodiment;

Figure 3c

a schematic plan view of a reflector structure, which is designed as a combination of two dipole structures according to an embodiment;

Fig. 3d

a schematic plan view of a reflector structure comprising three dipole structures each arranged at an angle to one another according to an embodiment;

Fig. 4

a schematic view of a reflector opposite the reflector from Fig. 1 is expanded by a housing part according to an embodiment;

Fig. 5

a schematic side sectional view of a reflector in which the substrate comprises vias according to an embodiment;

Fig. 6

a schematic block diagram of an antenna device, a reflector and an antenna according to an embodiment;

Fig. 7

a schematic block diagram of an antenna device in which a plurality of reflector structures according to. Figure 3c on the substrate according to an embodiment;

Fig. 8

a schematic block diagram of an antenna device comprising a horn antenna according to an embodiment;

Fig. 9

a schematic block diagram of an antenna device in which a substrate has an uneven shape according to an embodiment;

Fig. 10

a schematic plan view of a substrate on which a plurality of reflector structures and electrical subcircuits are arranged according to an embodiment;

Fig. 11

a schematic side view of the reflector from Fig. 1 to illustrate the function of the impressed phase function according to an embodiment;

Fig. 12

a schematic side view of an antenna device which is designed as a folded reflect array antenna according to an embodiment;

Fig. 13

a schematic view of an antenna device, the horn antenna and the reflector according to. Fig. 1 includes according to an embodiment; and

Fig. 14

a schematic representation of a reflect array according to the prior art.

Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally identical or identically acting elements, objects and / or structures in the different figures are provided with the same reference numerals, so that those shown in different exemplary embodiments Description of these elements is interchangeable or can be applied to one another.

Fig. 1 shows a schematic block diagram of a reflector 10. The reflector 10 comprises a substrate 12 and a plurality of reflector structures 14 which are arranged on a surface of the substrate 12. The multiplicity of reflector structures 14 is designed to reflect an incident electromagnetic wave 16 (radio signal). The reflector 10 further includes an electronic circuit 18 disposed on the same side of the substrate as the plurality of reflector structures. The electronic Circuit 18 is configured to control an antenna (not shown) when the antenna is connected to the electronic circuit. The antenna can be, for example, the antenna that generates or transmits the electromagnetic wave 16.

The substrate 12 can be any desired carrier material, such as, for example, low-loss HF materials (HF = high frequency). Low-loss HF materials can be obtained on the basis of PTFE composite materials (PTFE = polytetrafluoroethylene or polytetrafluoroethene). As an alternative or in addition, the substrate can be at least partially a silicon substrate (wafer or parts thereof) or around a printed circuit board (PCB). The substrate 12 can have one or more layers (layers) which are connected to one another or separated by intermediate layers. The intermediate layers can be metallic layers, for example, which enable shielding from the electromagnetic wave 16 and / or a supply of electronic components with a supply or reference potential (ground). The intermediate layers can also be air layers; That is, two layers of the substrate can be connected to one another by means of spacers. It is also conceivable that different layers 22a and 22b or 22b and 22c have an intermediate layer of air and are, for example, screwed together or the like. The intermediate air layers can also be used to accommodate reflector structures or act as reflector structures.

The multiplicity of reflector structures 14 is arranged, for example, on a first main side of the substrate 12, that is to say on a side of the substrate 12 that is arranged facing the incident electromagnetic wave 16. Although the electronic circuit 18 is described in such a way that it is arranged on the same side as the plurality of reflector structures 14, the electronic circuit can also be arranged in whole or in part (for example in the form of subcircuits) on another, roughly opposite side of the substrate 12 be. The plurality of reflector structures 14 and / or the electronic circuit 18 can also be arranged wholly or partially on or in the substrate 12, for example if the substrate 12 is a multilayer structure. In simple terms, a further layer of the substrate 12 can be arranged with respect to some or all of the reflector structures 14 and / or the electronic circuit 18, so that the related reflector structure and / or the electrical circuit 18 are covered by the further layer.

The reflector structures 14 can comprise electrically conductive materials such as metals or semiconductors. A surface geometry of the plurality of reflector structures can be selected such that the respective surface shape of the reflector structures 14 and / or their relative position to one another impresses a phase function on the incoming electromagnetic wave 16. For example, the electrically conductive material can be platinum, gold, silver, aluminum, copper, a (doped) semiconductor or the like. The multiplicity of reflector structures can be arranged on the substrate 12, for example, by means of an adhesive, pressure or sputtering process or by means of vapor deposition. Alternatively, the plurality of reflector structures can be formed in the form of island structures in a PCB by etching or milling. At least one reflector structure can be arranged by means of chemical gold plating or by vapor deposition.

A phase function impressed by the reflector structures 14 on the electromagnetic wave 16 can be designed such that the electromagnetic wave 16 is focused as a result of the reflection and is collimated or at least reflected by the reflector 10 in a less scattered manner. The impressed phase function can simulate a curvature of the reflector 10, for example convex or concave. The multitude of reflector structures are matched to one another based on the phase function in such a way that the electromagnetic wave 16 is reflected locally differently (direction, polarization, etc.) over the areal distribution and configuration of the reflector structures 14, so that the phase function of the electromagnetic wave 16 is impressed. Furthermore, the phase function can be used to obtain beam shaping (beam contour or contoured beam).

Fig. 2 shows a schematic side sectional view of a reflector 20. The reflector 20 comprises the substrate 12, the substrate 12 comprising a circuit board or being embodied as a multi-layer circuit board. The substrate 12 comprises a first layer 22a, a second layer 22b and a third layer 22c, which together form parts of a stack, with a first at least partially electrically conductive layer 24a between the first layer 22a and the second layer 22b and between the second layer 22b and the third layer 22c, a second at least partially electrically conductive layer 24b is arranged. The layers 22a, 22b and / or 22c can for example comprise an epoxy material, a semiconductor material and / or a glass fiber material such as FR-4, Kapton or the like, which can be glued together. For better understanding, but without a limiting effect, the stack of the substrate 12 is described in such a way that the plurality of reflector structures 14 at an upper end of the substrate 12 and the electronic circuit comprising electronic subcircuits 18a-c are arranged at a lower end of the stack. It is obvious that, depending on the orientation of the reflector 20 in space, the designation “top” or “bottom” can be replaced by any other designation. Alternatively, a multi-layer substrate can also comprise only one layer and one conductive layer.

The conductive layers 24a and 24b can, for example, comprise metallic materials and can be used or contacted as a ground plane. In addition, the conductive layers 24a and / or 24b enable (possibly complete) reflection of the electromagnetic wave 16. This can relate to portions of the electromagnetic wave 16 that are not reflected by the reflector structures 14 and penetrate into the substrate 12. Arranging the electronic circuit or subcircuits 18a, 18b and / or 18c on a side of the conductive layers 24a and / or 24b facing away from the incident electromagnetic wave 16 enables the electronic subcircuits 18a-c to be shielded from the electromagnetic wave . During operation, this offers advantages in particular with regard to a low electromagnetic coupling of the electromagnetic wave 16 into circuit structures, which would lead to an impairment of the functionality of the electronic circuit. The shielding thus enables an increased electromagnetic compatibility (EMC) of the reflector 20. Furthermore, the arrangement of the electronic subcircuits 18a-c on a different side than the plurality of reflector structures 14 enables the reflector structures 14 to use more space on the top of the stack, since there is no space is required for the electronic circuit.

At least one reflector structure 14 is arranged in a substrate plane different from the top side of the substrate 12, for example as a structure arranged on or in the metallic layer 24a. For example, the metallic layer 24a can be structured. This enables a higher (surface) density of the reflector structures 14 in relation to the electromagnetic wave 16, so that a reflected portion of the electromagnetic wave 16 to which a phase function is applied is increased. During operation, this enables a smaller proportion of the electromagnetic wave 16 to be coupled into the electrically conductive layer. Alternatively or additionally, a higher or the entire portion of the electromagnetic wave 16 can be acted upon with a phase function. The phase function of the reflected electromagnetic wave can, compared with the incoming electromagnetic wave 16, have a higher degree of linearity, which leads to an increased tolerance robustness.

Alternatively, it is also conceivable that one or more electronic subcircuits 18a-c are arranged facing the electromagnetic wave 16 on the first layer 22a. Alternatively or additionally, one or more electronic subcircuits 18a-c can be arranged in the substrate 12, for example on the second layer 22b or the first or second electrically conductive layer 24a or 24b.

Another layer (second layer 22b) is located under the ground plane 24a, which has an electrical function or can serve purely for the stability of the printed circuit board. Underneath is a further ground surface 24b, which, for example, galvanically separated from the upper ground surface 24a, can form the ground surface for the substrate layers on the underside of the circuit board for the active electronics (electronic subcircuits 18a-c). The electronic components for controlling a feed antenna (not shown) are located on the underside of a further layer (third layer 22c) for the electronics. Alternatively, the substrate 12 can also comprise only one layer, two layers or more than three layers. In simple terms, the second layer 22b can not be arranged or can be in the form of several layers.

The reflector structures 14 can also be embodied integrated (embedded) in one of the layers 22a, 22b or 22c, for example as conductive "islands" of a printed circuit board. If the second layer 22b is not arranged, for example, only one of the metallic layers 24a or 24b can be arranged between the layers 22a and 22c.

Furthermore, the reflector structures 14 can have different polarization directions (preferred directions) from one another. Different directions of polarization can be arranged in different substrate planes. The substrate planes can be arranged parallel to a substrate surface (the side of the substrate 12 facing or facing away from the electromagnetic wave 16).

The substrate can, for example, comprise a liquid crystal (LC) substrate layer which is arranged such that the reflector structures are located between a (virtual) source of the electromagnetic wave and the LC substrate layer. By means of the LC substrate layer, a phase allocation of the main or subreflector on the basis of a printed circuit board can be realized in a readjusting manner, that is to say reflection properties can be influenced based on an activation of the liquid crystal elements.

In other words shows Fig. 2 a possible layer structure of a main reflector circuit board. The top layer (ie above the first layer 22a) is formed by the reflective elements (reflector structures 14) which can impress a phase function of the incident radiation 16 and which are located on a substrate (first layer 22a). Under this substrate there is a metallic layer 24a, which serves, for example, as a ground plane and ensures the reflection of all incident rays.

Instead of two galvanically separated ground surfaces 24a and 24b for reflective elements and electronics, reflector 20 can also have only one common ground surface in the layer structure and therefore for reflective elements 14 and electronics 18a-c without any additional intermediate layer for the stability of the circuit board.

The (upper) substrate layers of the main reflector for the reflective elements (substrate layers 22a) can be made both single-layer and multi-layer, with further reflective elements being able to be arranged between the metallic layers in the multi-layer embodiment. Furthermore, adhesive layers that physically connect these layers (multi-layer reflect array) can be arranged. One advantage, possibly the main advantage, of the multilayer design is the greater realizable bandwidth of the main reflector. The same applies to the layers of the sub-reflector, if it is designed as a printed circuit board version.

The lower substrate layers (22c) of the main reflector for the electronics can be single-layered or multi-layered, with multiple layers in turn being able to have metallic layers with conductor tracks and adhesive layers that connect the different substrate layers.

Individual substrate layers of the main reflector circuit board or the subreflector circuit board can be glued or fixed / held together mechanically or by other means.

The Figures 3a-d each show schematic plan views of possible embodiments of the reflector structures.

Fig. 3a shows a schematic plan view of a reflector structure 14-1, which is designed as a rectangle with a first side dimension a and a second side dimension b.

The side dimensions a and b can have a different or equal value (square).

Figure 3b shows a schematic plan view of a reflector structure 14-2, which is designed as an ellipse. A ratio of major and minor axes is arbitrary.

Figure 3c shows a schematic plan view of a reflector structure 14-3, which is designed as a combination of two dipole structures 26a and 26b. The dipole structures 26a and 26b are arranged perpendicular to one another, which enables a reflection of incident electromagnetic waves with different polarization directions that is highly isolated or decoupled from one another. A perpendicular arrangement of the dipole structures 26a and 26b enables, for example, a reflection of mutually perpendicular polarization directions, for example horizontally and vertically, these orientations each or together being able to rotate freely in space or be referred to differently. Alternatively, the dipole structures 26a and 26b can also have an angle different from 90 ° and / or reflect directions of polarization which have the same or a different angle.

The dipoles 26a and 26b each have an increased degree of reflection when the electromagnetic wave is received with a polarization that corresponds to the arrangement of the respective dipole 26a or 26b and, in contrast, a reduced degree of reflection when the electromagnetic wave with another, in particular with a polarization direction arranged perpendicular thereto is received. If the electromagnetic wave is received with a first polarization, for example, the dipole structure 26a has a high (first) degree of reflection, for example. If the electromagnetic wave is received with a second polarization that is different from the first polarization, for example perpendicular thereto, then the dipole structure 26a has a lower (second) reflectance. The first polarization can be referred to as the preferred direction with respect to the dipole 26a. The dipole 26b has, for example, a high (third) reflectance in the second polarization and, if the electromagnetic wave has the first polarization, a low (fourth) reflectance with which the electromagnetic wave is reflected.

The first and third reflectivities are greater than the second and fourth reflectivities. The first and the third or the second and the fourth reflectance can also be the same. In simple terms, the dipole 26a can be designed to the to reflect the first polarization and the dipole 26b to reflect the second polarization. The dipole structures 26a and 26b can also be designed in order to impress mutually different phase functions on a reflected electromagnetic wave.

Several different polarizations can be obtained by connecting a plurality of antenna structures or elements to the electronic circuit, a first subset of the antenna structures or elements being designed to generate an electromagnetic wave with a first polarization and a second subset of the antenna structures or elements is designed to generate an electromagnetic wave with a second polarization. In addition, further antenna structures or elements can be arranged which are designed to generate an electromagnetic wave with at least one further polarization.

Fig. 3d shows a schematic top view of a reflector structure 14-4, which comprises three dipole structures 26a, 26b and 26c each arranged at an angle to one another, which enables reflection of three corresponding polarizations. The dipole structures 26a-c can have any desired angle to one another and, for example, be adapted to polarizations of electromagnetic waves to be transmitted. Alternatively, more than three dipole structures or only one dipole structure can be arranged.

Alternatively, the reflector structures can also have any other shape, such as a polygon shape, a circular shape, a free shape or a combination of shapes and / or dipole structures.

In other words, when the main or subreflector is designed as a reflect array, the reflective elements can have any geometry. Furthermore, any method can be used to implement the desired phase change on the aperture of the reflector, for example a variable size of the elements, attached line pieces and / or a rotation of the elements with respect to one another.

Fig. 4 shows a schematic view of a reflector 40, which is widened in relation to the reflector 10 such that a housing part 28 is arranged on a side of the substrate 12 facing away from the reflector structures 14. The housing part 28 can be used, for example, as a cover for the electronic circuit which the housing part 28 facing on the substrate 12 is arranged. The housing part 28 may comprise non-conductive (e.g., comprising plastic materials or resin materials) or conductive materials (e.g., metals). In simple terms, the housing part 28 can be a metallic cover.

A radome structure 32 is arranged on the side of the substrate 12 facing the reflector structures 14. The substrate 12 is shown arranged offset with respect to the housing part 28 and the radome structure 32 only for the sake of better illustration; That is, the substrate 12, the housing part 28 and the radome structure 32 can also be arranged in such a way that the substrate 12 is enclosed (housed) by the housing part 28 and the radome structure 32. The housing can be waterproof and / or chemically resistant.

The radome structure 32 comprises at least regionally an electrically conductive structure 34. The electrically conductive structure 34 is designed to reflect the electromagnetic wave and is arranged with respect to the plurality of reflector structures 14 so that the electromagnetic wave reflected by the electrically conductive structure 34 in the direction the plurality of reflector structures 14 is directed and is reflected again by these. If, for example, an antenna is arranged between the housing part 28 and the radome structure 32 (for example on or in the substrate 12), this antenna can be designed to emit the electromagnetic wave in the direction of the electrically conductive structure 34, so that the electrically conductive structure 34 the electromagnetic wave is reflected in the direction of the reflector structures 14. The electrically conductive structure 34 can provide the function of a subreflector. The sub-reflector can be arranged as part of a double reflector system in which the reflector 10 or 20 is arranged as the main reflector. The reflector structures 14 can then provide the electromagnetic wave with the phase function and transmit it (through the radome structure 32). As an alternative or in addition, the radome structure 34 can also comprise a further multiplicity of reflector structures.

In other words, a radome layer can be arranged over the reflective elements / the electronics of the main reflector circuit board in order to cover the elements and to protect them from corrosion and external influences or at least to reduce the influence. This radome position can also change the reflective properties of the reflective elements or serve for thermal heat dissipation for the electronics.

Fig. 5 shows a schematic side sectional view of a reflector 50, in which the substrate 12, compared to the reflector 20, comprises through-contacts (so-called vias) 36a and 36b, so that electrical signals from the electronic circuit 18 through the substrate 12 to the side opposite the electronic circuit 18 of the substrate 12 can be conducted. An antenna 38 is arranged on the substrate 12 and is designed to transmit a radio signal, for example in the form of the electromagnetic wave 16. The antenna 38 is connected, for example, by means of bonding wires 41a and 41b to the plated-through holes 36a and 36b and consequently to the electronic circuit 18. The electronic circuit 18 is designed to control the antenna 38 so that parameters of the electromagnetic wave 16, such as a signal shape, a transmission duration, a signal amplitude and / or a transmission frequency, are influenced by the activation of the electronic circuit 18. The reflector structures (not shown) are arranged on the same side of the substrate 12 as the antenna 38.

Alternatively or additionally, reflector structures can also be arranged in the substrate 12. Alternatively, the electronic circuit 18 can also be arranged on the same side as the antenna 38 on the substrate 12 and / or in the form of partial circuits. Arranging the antenna 38 on the substrate 12 enables a highly integrated interconnection of the electronic circuit 18 and antenna 38, which can lead to low power losses and consequently efficient operation. The reflector 50 can therefore also be described as an antenna device which comprises the electronic circuit 18, the substrate 12 and the antenna 38.

The antenna 38 can be any antenna. For example, it can be an on-chip feed antenna, a patch antenna, a PIFA antenna, a waveguide antenna, a silicon-based antenna or any other antenna.

For example, if the Fig. 4 described radome structure comprising the electrically conductive structure combined with the antenna device 50, an antenna shape comprising a double reflector system can be obtained. This antenna shape can be designed, for example, as a Cassegrain antenna or as a Gregorian antenna, so that an integrated Cassegrain antenna or an integrated Gregorian antenna can be obtained.

In other words shows Fig. 5 an example of the connection of the electronic components of the lower layers with the on-chip feed antenna on the top of the main reflector circuit board. In this example, the electronics are connected to an SMD on-chip antenna by means of plated-through holes (vias) and optional bonding wires. For example, the sub-reflector 42 can be part of a radome structure.

Fig. 6 shows a schematic block diagram of an antenna device 60 comprising the substrate 12 on which the plurality of reflector structures 14 are arranged. The antenna 38 is arranged on the substrate 12 on the same side as the plurality of reflector structures 14 and is designed to generate and emit the electromagnetic wave 16. The electromagnetic wave 16 can be emitted (spatially) broadly, ie with a large opening angle. This means that the electromagnetic wave 16 can have a low directivity. With respect to the substrate 12, a further reflector structure, hereinafter referred to as subreflector 42, is arranged. The sub-reflector 42 can be, for example, a concave or convex shaped conductive layer. Alternatively, the subreflector 42 can also be planar, for example comprising a substrate and / or a circuit board with reflector structures which are designed to impress a phase function on the received and reflected electromagnetic wave 16. In simple terms, the sub-reflector 42 is arranged and designed to scatter the electromagnetic radiation received by the antenna 38 and to reflect it at least partially in the direction of the reflector structures 14. The reflector structures 14 are designed to reflect the electromagnetic wave 16 reflected by the subreflector 42 again and to adapt the phase function of the electromagnetic wave 16 in such a way that the electromagnetic wave 16 is bundled with respect to the characteristics of the antenna 38. For example, the electromagnetic wave 16 can be emitted approximately or completely collimated, so that the antenna device 60 can be used as a directional radio antenna.

Fig. 7 FIG. 4 shows a schematic block diagram of an antenna device 70 in which a multiplicity of reflector structures 14 - 3 are arranged on the substrate 12. The electronic circuit comprises the subcircuits 18a and 18b, which are arranged on the same side of the substrate 12 as the reflector structures 14 - 3 and the antenna 38. The electronic subcircuits 18a and 18b are connected to the antenna 38 by means of so-called microstrip lines (MSL) 43a and 43b, respectively. The sub-reflector 42 is with respect to the substrate 12 or with respect to the antenna 38 and / or the reflector structures 14-3 tiltable by an angle α. The subreflector is convexly shaped or is designed to impress a convex phase function on the electromagnetic wave. The angle α can be, for example, less than 90 °, less than 60 ° or less than 30 °. With the subreflector 42, the electromagnetic wave can also be tilted in space with respect to the impressed phase function, so that overall a radiation characteristic with which the electromagnetic wave is reflected by the reflector structures 14-3 is changed.

For example, the electromagnetic wave can be reflected in a spatial direction that changes with the angle α. The sub-reflector 42 is also movable along an axial direction 44. A distance between the subreflector 42 and the substrate 12 or the antenna 38 can thus be varied along the axial direction 44. The axial direction 44 runs, for example, parallel to a surface normal 46 of the substrate 12. A reduced distance between the antenna 38 and the subreflector 42 can, depending on the scattering characteristics of the subreflector 42, lead to a narrowing or widening of a radiation lobe of the electromagnetic wave. That is to say, a focus of the electromagnetic wave that is emitted by the reflector structures 14 - 3 is variable with the distance or the movement along the axial direction 44. This enables the directivity of the antenna structure 70 to be adjusted or corrected, for example due to changing environmental influences such as heating and / or changing materials between the antenna device 70 and a further antenna device with which the antenna device 70 communicates.

Alternatively or in addition, the subreflector 42 can also be movable along a lateral direction 48 which is arranged perpendicular to the surface normal 46. Alternatively, the subreflector 42 can also be arranged rigidly or only tiltable by the angle α or movable along the direction 44.

A position of the dipoles of the reflector structures 14-3 can be adapted to one polarization or to a plurality of polarizations with which the electromagnetic wave is emitted by the antenna device 70. Alternatively or in addition, other reflector structures can also be arranged. The antenna 38 is designed to guide an electromagnetic wave transmitted in the direction of the antenna device and received by the antenna device 70 to the electrical circuit (not shown) or another electrical circuit which is arranged, for example, on a side of the substrate 12 facing away from the antenna 38 is.

As an alternative, the substrate 12 or the (main) reflector can also have a plurality of antennas 38, which can be constructed identically or differently from one another. With respect to the plurality of antennas, a plurality of sub-reflectors 42 may be arranged. For example, each sub-reflector can be assigned to one of the antennas arranged. This enables a multi-antenna device to be constructed.

Fig. 8 FIG. 11 shows a schematic block diagram of an antenna device 80 which comprises an antenna 38 ′. The antenna 38 'is designed as a horn antenna. A subreflector 42 'is arranged with respect to the antenna 38' and is designed to simulate a concave shape by means of the phase function. The subreflector 42 'can, for example, be designed as a concave metallic element. Alternatively, the subreflector 42 'can also be designed as a (flat) board which is designed to impress a corresponding phase function by means of a suitable arrangement of reflector structures.

The antenna device 80 can be used, for example, as a Gregorian antenna. The shape of the sub-reflector 42 or 42 'can be selected independently of an embodiment of the antenna 38 and 38'. For example, the antenna device 80 can also include the antenna 38 and / or the subreflector 42.

Fig. 9 shows a schematic block diagram of an antenna device 90, in which a substrate 12 '(main reflector) has an uneven shape. This is obtained, for example, by an arrangement of a plurality of (possibly planar) partial substrates 12a-e arranged at an angle to one another. This can also be referred to as a sector paraboloid or as a multi-faceted reflect array (reflector having multiple surfaces). By means of the partial substrates 12a-e which are inclined to one another, a concave or convex or piece-wise continuous shape (for example a parabolic shape) of the substrate 12 'and thus of the main reflector can be obtained. To put it simply, the main reflector and / or the substrate 12 'can be configured in several parts, wherein the parts can be arranged parallel to one another or at an angle. The antenna 38 is arranged shifted from a central position, for example (so-called offset feed). Alternatively, the antenna 38 can also be arranged in a geometric or area-based center of gravity. The antenna device 90 can also be described as a 1D multi-faceted reflect array configuration.

In other words, the main reflector based on printed circuit boards with the electronics for controlling the feed antenna (s) can be designed as a sector paraboloid (multi-faceted reflect array) and / or in a physically curved shape (conformal antenna) with one or more printed circuit boards to achieve the desired phase function to realize. The electronics for controlling the feed antenna (s) are arranged on at least one of these circuit boards (i.e. sectors, facets or panels 12a-e). A subreflector based on printed circuit boards can, for example, be constructed from a plurality of printed circuit boards in sector form. The advantage of a sector shape is that, compared with a flat design, a higher bandwidth of the antenna can be realized and a higher phase reserve of the reflector structure can be obtained.

Fig. 10 shows a schematic plan view of the substrate 12, on which a plurality of reflector structures 14-1 and subcircuits 18-d are arranged. Alternatively or additionally, further and / or different reflector structures can also be arranged.

Fig. 11 shows a schematic side view of the reflector 10 to illustrate the function of the impressed phase function, wherein the explanations can be transferred to a subreflector. The phase function impressed by the reflector structures 14 on the electromagnetic wave 16 enables implementation of a virtual structural shape of the reflector 10. The implemented virtual parabolic shape of the reflector is shown by the dashed concave line. For example, the reflector 10 can have a planar substrate 12 with the reflector structures 14 arranged thereon. By means of the phase function, however, the electromagnetic wave 16 can be reflected as if it were reflected by a concave (or alternatively convex) or parabolic reflector.

Fig. 12 shows a schematic side view of an antenna device 120, which is designed as a folded reflect array antenna. The antenna device 120 comprises, for example, the horn antenna 38 'or, alternatively, any other antenna shape. A subreflector in the form of a polarizing grating or a slot array 44 is arranged with respect to the antenna 38 ′. The polarizing grating or slit array 44 is designed to polarize and reflect the electromagnetic wave 16 when it has a first polarization. The reflector structures 14 are designed to rotate a polarization of the electromagnetic wave and to focus the electromagnetic wave 16. Thus, for example, the slot array 44 can be formed be in order to let the electromagnetic wave 16 pass largely or completely when it has the rotated (second) polarization.

The subreflector can be designed as a physically curved variant convex (for example for a Cassegrain antenna), concave (for example for a Gregorian antenna) or also as a printed circuit board (reflect array). A folded antenna (folded reflect array) can also be arranged as a reflector system.

A focussing or contoured beam function of the main reflector based on printed circuit boards as a reflect array is still given in such a case. As a sub-reflector, for example, a polarization-selective grating of a size similar to or the same as that of the main reflector can be attached above it. The feed antenna can also be located in a position below the subreflector grid. The incident beams from the feed antenna are reflected by this grid in a polarization-dependent manner, whereby the polarization can be partially rotated during the reflection. During the reflection on the main reflector reflect array, the polarization of the incident radiation is then partially rotated again and at the same time focused or formed in a deliberate manner. The rays can now pass the subreflector without reflection. This folded shape of the antenna can also be made very compact, however, due to the polarization selectivity of the subreflector, it can only be implemented with one polarization and certain reflective elements on the main reflector that rotate the polarization of the incident rays when the reflection is carried out.

Fig. 13 FIG. 11 shows a schematic view of an antenna device 130 comprising the horn antenna 38 ′ and the reflector 10. By means of the reflector 10, a reflector property analogous to a parabolic main reflector is obtained. With respect to the reflector 10, the subreflector 42 is arranged, which reflects the electromagnetic wave 16 emitted with an opening angle of 2 ϑ _f and throws it back in the direction of the reflector 10. With regard to the reflector 10, this acts like a virtual antenna (virtual feed) 38 _v , which emits the electromagnetic wave 16 with the opening angle 2 ϑ _vf . In simple terms, this implements a function of a Cassegrain antenna.

In simple terms, some of the exemplary embodiments described above can be designed as a double reflector system, for example as a Cassegrain antenna, Gregorian antenna or folded antenna. A feed antenna can be arranged centrally on a main reflector and be designed around the subreflector to irradiate (illuminate), which in turn is designed to illuminate the main reflector. The sub-reflector can virtually mirror the function of the feed antenna via the main reflector. The virtual mirror point can be shifted by the convex or concave (Gregorian antenna) shape of the subreflector in contrast to a reflection on a planar metallic surface. Thus, the entire antenna device can be made very compact. The main reflector can be designed or designed to be parabolic in order to implement a corresponding phase function, ie it leads to a collimation of the incident radiation and thus to a directional effect. The antenna can therefore combine high directivity with a very compact design.

The exemplary embodiments relate to a main reflector, which is designed as a printed circuit board (PCB), on the lower or upper side (or another side) of which the electronics for feeding the feed antenna are additionally located. The elements of the reflect array and a feed antenna are arranged on one side (for example the top). This feed antenna can be controlled by electronics that are located on the same or a different side or on both sides of the circuit board.

In exemplary embodiments, the electronic circuit (active electronics) can be located on the same side of the substrate (main reflector) as the reflector structures and can be designed to control the feed antenna from there. This can be done, for example, by means of conductor tracks, microstrip configurations, bond wire connections or the like.

The feed antenna can be any antenna and have a narrow or a wide radiation characteristic. The feed antenna can be designed, for example, as an on-chip antenna, horn antenna, open waveguide or phased array antenna. The feed antenna can also comprise several distributed antenna elements which can be excited to emit radiation individually or in groups. Further examples of feed antennas are, for example, substrate-integrated waveguides, possibly with horn, (planar) mode converters with attached horn, packaged antennas, printed planar antennas such as a patch antenna, PIFA antennas or the like.

The feed antenna can comprise one or more individual feed antennas with the same or different polarizations. In combination with certain reflective elements on the main or subreflector levels, it can also be polarization-dependent a multiplex, demultiplex or duplex transmission of electromagnetic waves (radio signals) can be realized. For example, crossed dipoles can be arranged as reflective elements. The individual dipolar arms can selectively reflect the phase of the incident rays with polarization in a longitudinal direction. As crossed dipoles, the scattering elements (reflector structures) can therefore reflect different, for example orthogonal linear polarizations, selectively with high isolation and thus impress different phase assignments on the different, for example orthogonally polarized beams. This enables, for example, a spatial separation, ie two focal points, of the two linearly orthogonally polarized feed antennas. That is, two feed antennas are arranged.

In exemplary embodiments, the feed antenna can be arranged at a (e.g. vertical) position, ie perpendicular to the aperture of the main reflector, which is on the plane of the main reflector (e.g. in the form of a patch antenna), but higher (e.g. in the form of a horn antenna) also located deeper (e.g. integrated in one of the layers of the substrate).

Embodiments include two or more feed antennas which are designed to each emit an electromagnetic wave at frequencies different from one another (so-called multi-band reflect array). Alternatively or in addition, the feed antennas can be controlled using the time division multiplex method.

A horizontal (lateral) position of the feed antenna (in the aperture plane of the main reflector) can be located centrally or at another position (so-called offset feed). Furthermore, the axial or lateral position of the sub-reflector can be variable. As an alternative or in addition, the subreflector can also be tilted by any desired angle α (e.g. less than 90 °).

One (possibly essential) function of the double reflector system is, for example, beam bundling, that is, a high level of directivity of the antenna. The antenna can thus be used for directional radio and / or point-to-point connections (direct connections). The possibility of a contoured radiation (Contured Beam) by means of suitable phase assignment of the main reflector reflect array is also possible. A main application here is, for example, satellite radio. The phase assignment (phase function) can also be implemented in such a way that multi-beam, tilted beam or any other feasible form of radiation from the overall antenna is achieved.

In exemplary embodiments, the main or subreflector can be moved mechanically relative to one another in order to carry out beam control or pivoting, for example.

The above-described exemplary embodiments describe realizations of a main reflector that combines the electronics and the radiation reflection with specific phase assignment of the radiation from a subreflector, for example in a Cassegrain antenna system or in a folding antenna on a printed circuit board. One advantage here is the compactness of the antenna system and the ability to integrate the electronics together with the reflector properties of the antenna on a printed circuit board.

Application examples can be used, for example, in directional radio links (point-to-point), satellite radio and / or in radar applications. Furthermore, antenna devices according to the exemplary embodiments described above can be used wherever a highly integrated antenna with a high level of directivity or contoured radiation is required. A Cassegrain reflect array antenna with main and sub mirror (reflector) as a printed circuit board design can be seen as a typical application example. The subreflector as a circuit board can be embedded in a radome housing that is permeable to radiation, while the main reflector circuit board is placed on a metallic housing, whose function includes protecting the electronics and shielding them (in terms of EMC) and / or dissipating heat from the electronic components. The two housing components can be joined together mechanically (possibly waterproof and / or chemical-resistant) and enclose the main reflector circuit board with an on-chip feed antenna. The connections to the outside, i.e. for contacting the antenna device, can be implemented, for example, in the form of a data connection and as a connection for the power supply.

Although the antenna and / or the antenna device have been described above in such a way that they are designed to generate and transmit the electromagnetic wave 16, exemplary embodiments can also be used to receive the electromagnetic wave 16 alternatively or in addition, so that it can be transmitted with the electronic circuit or another electronic circuit can be evaluated.

Although some aspects have been described in connection with a device, it goes without saying that these aspects also represent a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Analogously, aspects that have been described in connection with or as a method step also represent a description of a corresponding block or details or features of a corresponding device.

The above-described embodiments are merely illustrative of the principles of the present invention. It is to be understood that modifications and variations of the arrangements and details described herein will suggest others skilled in the art become evident. It is therefore intended that the invention be limited only by the scope of protection of the following patent claims and not by the specific details presented herein with reference to the description and explanation of the exemplary embodiments.

The research that led to these results was funded by the European Union.

Claims (12)

1. Antenna device (50; 60; 70; 80; 90; 120; 130) comprising:

   a reflector (10; 20; 40; 50), comprising

   a substrate (12);

   a plurality of reflector structures (14; 14-1-4) arranged on or in the substrate (12) and configured to reflect an incident electromagnetic wave (16); and

   an electronic antenna control circuit (18; 18a-d) arranged on or in the substrate (12);

   the antenna device further comprising:

   an antenna (38; 38') arranged on the substrate (12); and

   a subreflector (42; 42') configured to reflect the electromagnetic wave (16) emitted by the antenna (38; 38') at least partly in the direction of the plurality of reflector structures (14; 14-1-4), such that the electromagnetic wave (16) reflected by the subreflector (42; 42') is directed in the direction of the plurality of reflector structures (14; 14-1-4) and reflected again by the same;

   wherein the antenna (38; 38') is connected to the electronic antenna control circuit (18; 18a-d) and configured to generate the electromagnetic wave (16) based on a control of the electronic antenna control circuit (18; 18a-d) and to emit the same in a direction of the subreflector (42; 42'); and

   wherein the plurality of reflector structures (14; 14-1-4) are arranged in at least two differing substrate planes (22a, 22b) that are arranged parallel to a substrate surface that is arranged facing a direction in which the electromagnetic wave (16) is reflected.
2. Antenna device according to claim 1, wherein the plurality of reflector structures (14; 14-1-4) are configured to reflect the incident electromagnetic wave (16) such that the reflected electromagnetic wave (16) experiences beam focusing by the reflection at the plurality of reflector structures (14; 14-1-4).
3. Antenna device according to claim 1 or 2, wherein the substrate (12) includes a printed circuit board, wherein the printed circuit board includes a stack with at least a first layer (22a), a second layer (24a) and a third layer (22b), wherein the second (24a) layer is arranged between the first (22a) and the third (22b) layer, wherein the plurality of reflector structures (14; 14-1-4) are arranged at least partly at, on or in the first layer (22a), and wherein the second layer (24a) is at least partly electrically conductive.
4. Antenna device according to claim 3, wherein the second layer (22b) is formed as an electric ground plane.
5. Antenna device according to one of the preceding claims, wherein at least one partial circuit (18a-d) of the electronic antenna control circuit (18; 18a-d) is arranged on a side of the substrate that is facing away from an incident electromagnetic wave (16) impinging on the plurality of reflector structures (14; 14-1-4).
6. Antenna device according to one of the preceding claims, further including a radom structure (32) arranged with respect to the plurality of reflector structures (14; 14-1-4) and configured to at least partly reduce a mechanical or chemical influence of an environment of the plurality of reflector structures (14; 14-1-4) on the plurality of reflector structures (14; 14-1-4), wherein the radom structure (32) includes, at least in areas, an electrically conductive structure (34) or a further plurality of reflector structures that are configured to reflect the electromagnetic wave (16), wherein the electrically conductive structure (34) or the further plurality of reflector structures are arranged with respect to the plurality of reflector structures (14; 14-1-4) such that the electromagnetic wave (16) reflected by the electrically conductive structure (34) is directed in the direction of the plurality of reflector structures (14; 14-1-4) and reflected again by the same.
7. Antenna device according to one of the preceding claims, wherein the reflector includes a radom structure (32) that is arranged with respect to the plurality of reflector structures (14; 14-1-4) and configured to at least partly reduce a mechanical or chemical influence of an environment of the plurality of reflector structures (14; 14-1-4) on the plurality of reflector structures (14; 14-1-4).
8. Antenna device according to claim 6 or 7, wherein the radom structure (32) includes the subreflector (42; 42').
9. Antenna device according to one of claims 6 to 8, wherein the substrate (12) includes a printed circuit board, wherein the printed circuit board includes a stack with at least a first layer (22a), a second layer (24a) and a third layer (22b) and wherein the radom structure (33) is formed as radom layer on the substrate (12).
10. Antenna device according to one of the preceding claims, wherein an axial relative position of the subreflector (42; 42') with respect to the reflector (10; 20; 40; 50) is variable along an axial direction (44) parallel to a surface normal (46) of the substrate (12).
11. Antenna device according to one of the preceding claims, wherein a lateral relative position of the subreflector (42; 42') is variable with respect to the reflector (10; 20; 40; 50) along a lateral direction (48) perpendicular to a surface normal (46) of the substrate (12) or wherein an inclination (α) of the subreflector (42; 42') is variable with respect to a surface of the substrate (12) of the reflector (10; 20; 40; 50).
12. Antenna device according to one of the preceding claims, wherein the antenna (38, 38') comprises a plurality of antenna elements, wherein a first subset of the antenna elements is configured to generate the electromagnetic wave (16) with a first polarization direction and wherein a second subset of the antenna elements is configured to generate the electromagnetic wave (16) with a second polarization direction;
    wherein a first subset (26a) of the plurality of reflector structures (14; 14-1-4) is configured to reflect the electromagnetic wave (16) with a first degree of reflection when the electromagnetic wave (16) comprises the first polarization direction and to reflect the same with a second degree of reflection when the electromagnetic wave (16) comprises the second polarization,
    wherein a second subset (26b) of the plurality of reflector structures (14; 14-1-4) is configured to reflect the electromagnetic wave (16) with a third degree of reflection when the electromagnetic wave (16) comprises the second polarization direction and to reflect the same with a fourth degree of reflection when the electromagnetic wave (16) comprises the first polarization;
    wherein the first degree of reflection and the third degree of reflection have a greater value than the second degree of reflection and the fourth degree of reflection.

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