Antenna assembly

Abstract

The present invention relates to an antenna assembly (1) for use in a vehicle with a window pane (10), and for arrangement of the antenna assembly (1) on the window pane (10), wherein the antenna assembly (1) comprises a printed circuit board (2) having at least one opening (3) in the form of a slit, at least one stripline (5), arranged on a first side (4) of the printed circuit board (2), corresponding to the at least one opening (3), which stripline is arranged at least partially within a cutout provided on the first side (4) of the printed circuit board (2), and at least one secondary emitter (7), arranged on a second side (6) of the printed circuit board (2), corresponding to the at least one opening (3), wherein the secondary emitter (7) is spaced apart from the printed circuit board (2), wherein a releasable fastening of the at least one secondary emitter (7) is provided.

Description

[0001] Antenna arrangement

[0002] The invention relates to an antenna arrangement and a vehicle with the antenna arrangement.

[0003] Antennas for pulse radar radio systems operating in accordance with ultra-wideband (UWB) technology must have a very large relative bandwidth (of, for example, 12.5% ​​or more) of the respective radio system and must not generate any significant phase distortions within such a bandwidth, so that the group delay is as constant as possible.

[0004] In order to integrate such a radio system cost-effectively into existing vehicles (e.g. rail vehicles), an antenna arrangement is either mounted directly behind a front or rear windscreen or is at a greater distance from the aforementioned windscreens.

[0005] In both of these cases, however, it is problematic that the antenna arrangement is detuned or influenced by the window pane (for example a glass pane or a Plexi- / acrylic glass, as a single pane or a laminated glass) and thus the above-mentioned requirements regarding low phase distortion are no longer met.

[0006] In other words, a window pane made of optically transparent materials such as glass, Plexiglas or acrylic, depending on the material, material thickness and structure of the window pane through one or more material layers and material sequences, can have a resulting dielectric constant which can adversely affect the electromagnetic properties of an antenna device arranged behind it.

[0007] In principle, the window pane can be any electromagnetically permeable material, optically transparent or not, and can therefore only have the function of a radome, whereby the window pane can also be formed from a composite material or have coatings, such as filter layers for attenuating light of certain wavelengths.

[0008] To date, in order to mitigate this problem, antennas or antenna arrangements have been mounted outdoors (i.e. not behind a window in the interior of a vehicle, for example a driver's cab or cockpit), which has resulted in greater effort and therefore higher costs. Such costs are caused in particular by the necessary approval and / or by maintenance work resulting from harsh environmental conditions (such as snow, ice, etc.). On the other hand, for interior applications, many different assemblies with different dimensions are provided for installation directly on the window pane or at a greater distance from the window pane. The resulting high product variety requires corresponding warehousing, which also results in high effort and costs.

[0009] The task is therefore to provide an antenna arrangement which avoids the aforementioned disadvantages and yet meets the required technical properties.

[0010] The object of the invention is achieved by an antenna arrangement for use inside a vehicle with a window pane, and for fastening the antenna arrangement behind the window pane or for arranging the antenna arrangement on the window pane, wherein the antenna arrangement comprises a printed circuit board having at least one opening in the form of a slot, at least one strip line arranged on a first side of the printed circuit board corresponding to the at least one opening, which strip line is at least partially arranged within a recess provided on the first side of the printed circuit board in the metallization of the printed circuit board, and at least one secondary radiator arranged on a second side of the printed circuit board corresponding to the at least one opening, wherein the secondary radiator is arranged at a distance from the printed circuit board.

[0011] In other words, the antenna arrangement is designed to be mounted on a window pane within a vehicle, i.e., in the interior of the vehicle, adjacent to the window pane. This allows the antenna arrangement to radiate the energy generated from the interior of the vehicle to the outside via radio waves. An externally mounted antenna would have adverse and undesirable effects on the aerodynamics and design of the vehicle.

[0012] The antenna array itself can be mechanically connected and mounted to the vehicle using a fastening device that is held to the windowpane or another component within the vehicle. For example, an air bulkhead can be provided between the antenna array and the windowpane, thus eliminating the need for the antenna array to be directly adjacent to the windowpane.

[0013] According to the invention, the dimensioning of an excitation structure (i.e., slot and feed network, as well as a distance from the secondary radiator) is designed to ensure operation as required near a window pane as well as operation in free space. The proposed solution therefore has the advantage that only the secondary radiator needs to be replaced to meet different requirements. Such a replacement can be carried out in a simple manner.

[0014] This reduces the required product variety, as only a single antenna array or a single antenna system is required for all installation variants behind a window pane. If necessary, only the secondary radiator needs to be replaced during the project planning process, which can be achieved, for example, by using a custom, cost-effective circuit board or simple sheet metal parts.

[0015] Preferably, the antenna arrangement further comprises a shielding plate arranged on the second side corresponding to the circuit board, wherein the shielding plate is arranged at a distance from the circuit board. This has the advantage of achieving shielding in an undesired beam direction and, moreover, increasing the mechanical stability of the antenna arrangement.

[0016] According to a preferred embodiment, the at least one stripline is arranged substantially orthogonally to a main direction of extension of the at least one opening. This results in electromagnetic waves propagating through the opening in the direction of the secondary radiator. In this case, an opening is understood to be a recess in a metallization acting as a ground plane within or on one side of the circuit board.

[0017] Advantageously, a detachable fastening of the at least one secondary radiator is provided. For this purpose, for example, the secondary radiator can be secured by means of connecting elements such as spring clips and the like, thereby ensuring easy replacement.

[0018] The antenna arrangement preferably comprises a network for antenna feeding, which is connected to the at least one stripline. This enables control of the secondary radiator or a plurality of secondary radiators to adjust a directional characteristic. According to a preferred embodiment, the network for antenna feeding is arranged on the circuit board. This achieves a compact design of the antenna arrangement.

[0019] Advantageously, the antenna feeding network comprises at least one power splitter and at least one phase shifter, which are provided for controlling a large number of secondary radiators via a large number of striplines. A phase shifter can be provided as a fixed or controllable variant. In this way, in an array antenna which comprises two or more secondary radiators, the directional characteristic can be selected such that radiation above a horizontal plane is as low as possible. For example, side lobes of the antenna arrangement can be more than 12 dB weaker than a main lobe in the direction of the horizon, thereby enabling the use of a maximum transmission power permitted by regulatory authorities.

[0020] The antenna arrangement preferably comprises a second circuit board on which the at least one secondary radiator is arranged. This allows for easy replacement of the secondary radiator.

[0021] According to a preferred embodiment, the antenna arrangement comprises a second opening in the form of a slot, a second second stripline arranged on the first side of the circuit board corresponding to the second opening, and a second second secondary radiator arranged on the second side of the circuit board corresponding to the second opening, wherein the second secondary radiator is arranged at a distance from the circuit board. By means of such an arrangement, for example, suitable radiation in the direction of the horizon can be achieved with inclined panes, in particular if the two secondary radiators acting as antenna elements are fed by power splitters and phase shifters in such a way that the overall antenna characteristic is guided. With regard to the second opening, the same is also used in the present case to create a recess in a metallization acting as a ground plane within or outside.on one side of the circuit board.

[0022] Advantageously, the vehicle is a rail vehicle. Since the aforementioned antenna arrangement is designed to operate according to UWB technology, which is used in rail vehicles for distance measurements, such a configuration is advantageous.

[0023] Preferably, the antenna arrangement is arranged substantially parallel to a main extension direction of the window pane. This is particularly advantageous if the window pane is arranged substantially orthogonally to the desired radiation direction of a secondary radiator.

[0024] According to a preferred embodiment, the antenna arrangement is arranged at an angle inclined to a main extension direction of the window pane. This is advantageous if the window pane is not arranged substantially orthogonally to the desired radiation direction of a secondary radiator, but is instead inclined.

[0025] The object according to the invention is also achieved by a vehicle with a window pane and an antenna arrangement according to the invention arranged in an interior space behind the window pane.

[0026] In a further development of the invention, it is provided that the antenna arrangement is used for distance measurements in the traffic sector.

[0027] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of the embodiments, which are explained in more detail in conjunction with the drawings.

[0028] Figure 1 shows a perspective view of a first embodiment of an antenna arrangement for a vehicle;

[0029] Figure 2 shows a perspective view of a second embodiment of an antenna arrangement for a vehicle;

[0030] Figure 3 shows the second embodiment of the antenna arrangement in a side view;

[0031] Figure 4 shows a schematic representation of a first exemplary embodiment for the positioning of an antenna arrangement in a vehicle;

[0032] Figure 5 shows a schematic representation of a second exemplary embodiment for the positioning of an antenna arrangement in a vehicle; and

[0033] Figure 6 is a schematic representation of an embodiment of an antenna arrangement with a reduction in radiation.

[0034] Figure 1 shows a perspective view of a first embodiment of an antenna arrangement 1 for distance measurements in the traffic sector, which has only a secondary radiator 7 as an antenna element.

[0035] The antenna arrangement 1 comprises a printed circuit board 2 which has an opening 3 in the form of a slot. This opening 3 is in particular a recess in a metallization acting as a ground plane within or on one side of the printed circuit board 2. On a first side 4 of the printed circuit board 2, a stripline 5 is arranged corresponding to the at least one opening 3. This stripline 5 is arranged in the present case within a recess in the metallization provided in the printed circuit board 2. The recess in the metallization is provided in the first side 4 of the printed circuit board 2.

[0036] In the present case, the strip line 5 is arranged substantially orthogonally to a main extension direction of the opening 3.

[0037] Furthermore, the antenna arrangement 1 according to Figure 1 comprises a secondary radiator 7 arranged on a second side 6 of the circuit board 2 corresponding to the at least one opening 3. This secondary radiator 7 is arranged at a distance from the circuit board 2, for example, by suitable spacing means. The proposed arrangement of the secondary radiator 7 allows for its simple replacement.

[0038] Although this is not shown in Figure 1, it can be provided that the secondary radiator 7 is located on or on a second circuit board 9, which is arranged on the second side 6 of the circuit board 2.

[0039] Furthermore, Figure 1 shows a shielding plate 8 arranged on the second side 6 corresponding to the circuit board 2, which is arranged at a distance from the circuit board 2 and can be provided optionally.

[0040] A slot-coupled patch antenna is thus used, which consists of a printed circuit board 2 on which appropriate radio-frequency (RF) components are mounted for control purposes and which contains an opening 3 in the form of a slot excited by a stripline 5, wherein the opening 3 represents a recess in a metallization acting as a ground plane. The slot excites a secondary radiator 7 (i.e., the so-called patch), which in turn can be located on a separate simple printed circuit board 9 (shown in Figure 3).

[0041] Figure 2 shows a perspective view of a second embodiment of an antenna arrangement 1, which comprises two secondary radiators 7 and 17. In other words, it can be said that two antenna elements are operated as a group.

[0042] Accordingly, the antenna arrangement 1 for distance measurements in traffic areas according to Figure 2 comprises a printed circuit board 2 having two openings 3 and 13, each of which is designed in the form of a slot and represents recesses in a metallization acting as a ground plane. Furthermore, striplines 5 and 15 are provided on a first side 4 of the printed circuit board 2, each arranged corresponding to the openings 3 and 13.

[0043] The shielding plate 8, which is also optionally provided in Figure 2, extends over the entire length and width of the circuit board 2 and is thus arranged corresponding to it.

[0044] Although not shown in Figure 2, the antenna arrangement 1 comprises an antenna feeding network connected to the strip lines 5 and 15. This network can be arranged on the printed circuit board 2, for example on the first side 4 thereof.

[0045] The antenna feed network includes power dividers and phase shifters, which are designed to control the secondary radiators 7 and 17 via the striplines 5 and 15. In this way, an overall antenna characteristic can be directed, which, for example, allows for suitable radiation toward the horizon when mounted behind tilted windows.

[0046] Figure 3 shows a side view of the second embodiment of the antenna arrangement 1 for distance measurements in traffic areas, wherein the antenna arrangement 1 is arranged parallel to a window pane 10, in this example made of transparent glass.

[0047] In Figure 3 it is explicitly shown that the antenna arrangement 1 comprises a second printed circuit board 9 on which the two secondary radiators 7 and 17 are arranged.

[0048] Furthermore, the above explanations for Figure 2 also apply to Figure 3.

[0049] Figure 4 shows a schematic representation of a first exemplary embodiment for the positioning of an antenna arrangement 1 for distance measurements in the traffic sector.

[0050] In the present case, a glass pane 10 of a vehicle is shown, wherein the antenna arrangement 1 is arranged in an interior of the vehicle behind the glass pane 10. The vehicle can be, for example, a rail vehicle.

[0051] In the vehicle (not shown in the figure), for example a locomotive with a front window to an interior, such as the driver's cab of the locomotive or the passenger compartment of a bus with a front window, the previously described antenna arrangement is arranged in the interior behind the window 10.

[0052] The glass pane 10 is inclined by an angle a relative to a vertical, with the angle a being, for example, 22°. The antenna arrangement 1 is inclined in the same way, so that it is arranged substantially parallel to a main extension direction of the glass pane 10. The antenna arrangement 1 is spaced apart from the glass pane 10 by a distance d.

[0053] Figure 5 shows a schematic representation of a second exemplary embodiment for the positioning of an antenna arrangement 1 for distance measurements in the traffic sector.

[0054] Just as in Figure 4, the glass pane 10 is inclined by the angle a relative to a vertical. However, in contrast to Figure 4, the antenna arrangement 1 is not shown as being arranged substantially parallel to a main direction of extension of the glass pane 10, but rather as being oriented at an angle inclined to a main direction of extension of the glass pane 10.

[0055] This can be seen from the angle ß shown between a main extension direction of the antenna arrangement 1 and a vertical, which deviates from the angle a and is, for example, 13 °.

[0056] In Figure 5, the antenna arrangement 1 and the glass pane 10 are spaced apart from each other at the point with the smallest distance according to the distance d.

[0057] Figure 6 shows a schematic representation of an embodiment of an antenna arrangement 1 for distance measurements in the traffic sector with a reduction in radiation.

[0058] Based on a rotation center 11, the radiation is reduced by the angle u, which results in a corresponding deviation of the radiation direction from a horizontal (angle <p=0 ° ) erreicht wird . Diese Absenkung 12 wird auch als „Downtilt" bezeichnet . Die anhand des abgesenkten Pfeils indi zierte Hauptstrahlungsrichtung ändert sich vorliegend beispielsweise um einen Winkel von u=22 ° . Erfindungsgemäß erfolgt durch die vorstehend beschriebenen Leistungsteiler und Phasenschieber eine Anspeisung derart , dass eine Lenkung der Gesamt-Antennencharakteristik erzielt werden kann, wodurch beispielsweise eine geeignete Abstrahlung in Richtung Hori zont bei schräggestellten Scheiben erreicht wird .

[0059] Although the invention is described in detail by preferred

[0060] While the invention has been illustrated and described in more detail by means of exemplary embodiments, it is not limited to the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. Regardless of the grammatical gender of a particular term, this includes persons of male, female, or other gender identities.

[0061] List of reference symbols

[0062] 1 Antenna array 2 Circuit board

[0063] 3, 13 Opening

[0064] 4 first side of the circuit board

[0065] 5, 15 strip line

[0066] 6 second side of the circuit board 7, 17 Secondary radiation

[0067] 8 Shielding plate

[0068] 9 second circuit board

[0069] 10 glass pane

[0070] 11 Center of rotation 12 Downtilt

[0071] Distance a, ß, u, cp Angle

Claims

Patent claims 1. Antenna arrangement (1) for use inside a vehicle with a window pane (10), and for arranging the antenna arrangement (1) on the window pane (10), wherein the antenna arrangement (1) comprises a printed circuit board (2) having at least one opening (3) in the form of a slot, at least one stripline (5) arranged on a first side (4) of the printed circuit board (2) corresponding to the at least one opening (3), which stripline is at least partially arranged within a recess provided on the first side (4) of the printed circuit board (2) in the metallization of the printed circuit board, and at least one secondary radiator (7) arranged on a second side (6) of the printed circuit board (2) corresponding to the at least one opening (3), wherein the secondary radiator (7) is arranged at a distance from the printed circuit board (2), characterized in that a detachable fastening of the at least one secondary radiator (7) is provided.

2. Antenna arrangement (1) according to claim 1, wherein the antenna arrangement (1) further comprises a shielding plate (8) arranged on the second side (6) corresponding to the circuit board (2), wherein the shielding plate (8) is arranged at a distance from the circuit board (2).

3. Antenna arrangement (1) according to claim 1 or claim 2, wherein the at least one stripline (5) is arranged substantially orthogonal to a main extension direction of the at least one opening (3).

4. Antenna arrangement (1) according to one of claims 1 to 3, wherein the antenna arrangement (1) further comprises an antenna feeding network which is connected to the at least one stripline (5).

5. Antenna arrangement (1) according to claim 4, wherein the network for feeding the antenna is arranged on the circuit board (2).

6. Antenna arrangement (1) according to claim 4 or claim 5, wherein the antenna feeding network comprises at least one power splitter and at least one phase shifter, which are provided for controlling a plurality of secondary radiators (7, 17) via a plurality of striplines (5, 15).

7. Antenna arrangement (1) according to one of claims 1 to 6, wherein the antenna arrangement (1) further comprises a second circuit board (9) on which the at least one secondary radiator (7) is arranged.

8. Antenna arrangement (1) according to one of claims 1 to 7, wherein the antenna arrangement (1) further comprises a second opening (13) in the form of a slot, a second second stripline (15) arranged on the first side (4) of the circuit board corresponding to the second opening (13), and a second second secondary radiator (17) arranged on the second side (6) of the circuit board corresponding to the second opening (13), wherein the second secondary radiator (17) is arranged at a distance from the circuit board.

9. Antenna arrangement (1) according to one of claims 1 to 8, wherein the vehicle is a rail vehicle.

10. Antenna arrangement (1) according to one of claims 1 to 9, wherein the antenna arrangement (1) is arranged substantially parallel to a main extension direction of the window pane (10).

11. Antenna arrangement (1) according to one of claims 1 to 9, wherein the antenna arrangement (1) is arranged at an angle inclined to a main extension direction of the window pane (10).

12. Vehicle with a window pane (10) and an interior space behind the window pane (10), comprising the antenna arrangement according to one of the preceding claims, which is arranged in the interior space of the vehicle on the window pane (10).

13. Vehicle according to the preceding claim, wherein the antenna arrangement is used for distance measurements in the traffic area.

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