Multimode GNSS antenna for robust navigation

Abstract

The invention relates to a multimode GNSS antenna for robust navigation (10), comprising an antenna element (12) for receiving signals from a plurality of satellites, characterised in that the multimode GNSS antenna (10) has at least two ports (14a-14n), each of which is connected to the antenna element (12) via at least one feed point (16-22).

Description

[0001] 2024 / 168

[0002] 251544WO AG / ol

[0003] Multimode GNSS antenna for rugged navigation

[0004] GNSS navigation plays a crucial role in various modes of transportation, such as air traffic. Any malfunction or interruption of the GNSS service has a significant impact on the operation of an aircraft or other means of transport. This is particularly important when GNSS interference is intentionally created, as was the case recently during the Ukraine conflict, which also disrupted aircraft in Eastern European airspace.

[0005] It is therefore desirable to provide a possibility for more robust GNSS navigation.

[0006] It is known from the prior art to use multi-antenna systems for this purpose. Such systems have been used in both military and civil aviation to circumvent GNSS interference.

[0007] Such systems do not use a single antenna, as is currently used in aircraft (possibly with a second antenna for redundancy), but rather an array of antennas. The signals from these multiple antennas, if processed correctly, can be used to adaptively control the antenna beam, ensuring maximum signal strength in the direction of the GNSS satellite. Furthermore, minimum signal strength is directed towards the incoming interference signal, effectively preventing the authentic GNSS signal from being disrupted by the interference signal.

[0008] However, such multi-antenna systems are not standardized for use in air traffic. They are also often too large for air traffic.

[0009] The state of the art is known from the following publications: Caizzone et al., "A Miniaturized Multiband Antenna Array for Robust Navigation in Aerial Applications"

[0010] DE 10 2018 203 191 Al

[0011] DE 20 2018 002 095

[0012] The object of the invention is to provide a multimode GNSS antenna that is robust against interference and has compact dimensions.

[0013] The problem is solved according to the invention by the features of claim 1.

[0014] The multimode GNSS antenna according to the invention comprises an antenna element for receiving signals from multiple satellites. Furthermore, it has at least two ports, each connected to the antenna element via at least one feed point.

[0015] In a multimode antenna, a single antenna structure (for example, the PCB of a mobile device) is used. The position and orientation of the feed points are selected appropriately to obtain multiple receive modes from the same antenna structure (so that, for example, MIMO functionality can be provided in mobile devices). According to the invention, this concept is transferred to a GNSS antenna to make it more robust against interference. It is preferred that the multiple feed points are used in the same frequency band. Thus, according to the invention, it is not a multiband antenna, but an antenna that operates only in a single frequency band, namely the frequencies intended for GNSS. This is the frequency range between 1164 MHz and 1610 MHz.

[0016] It is preferred that each port is connected to two feed points. Furthermore, it is preferred that the multimode GNSS antenna has at least three feed points, each connected to at least two ports.

[0017] The multimode GNSS antenna can also be designed as a microstrip patch antenna or as a dielectric resonator antenna.

[0018] Furthermore, it is preferred that the ports are designed to receive signals with different polarizations, in particular vertical, horizontal, RHCP or LHCP polarization.

[0019] Furthermore, it is possible that each feed-in point is connected to exactly one port.

[0020] It is further preferred that the multimode GNSS antenna is manufactured using an additive manufacturing process, in particular 3D printing, and that the feed points are offset from each other vertically, so that they are located on different planes. Additionally, the feed points are preferably offset from each other horizontally, i.e., laterally. This further optimizes antenna performance by, for example, reducing the interaction between the ports (thus reducing the so-called "mutual coupling" between the antennas of the multi-antenna system).

[0021] Preferred embodiments of the invention are explained below with reference to figures.

[0022] They show:

[0023] Figure 1: a GNSS antenna known from the prior art,

[0024] Figure 2: a first embodiment of the multi-mode GN SS antenna according to the invention,

[0025] Figure 3: a second embodiment of the multi-mode GN SS antenna according to the invention, Figure 4: a third embodiment of the multi-mode GN SS antenna according to the invention.

[0026] The antenna known from the prior art according to Figure 1 has an antenna element (12) and two feed points (16, 18) connected to it. These are connected to a port (14) via a combiner.

[0027] A first embodiment of the multimode GNSS antenna (10) according to the invention is shown in Figure 2. It also has an antenna element (12). Two feed elements (16a, 16b) are mounted on this element and connected to a first port (14a) via a combiner. Furthermore, two additional feed points (18a, 18b) are provided, which are connected to a second port (14b) via a second combiner. Thus, multiple output ports can be provided.

[0028] Another possibility is shown in Figure 3. This antenna has four feed points (16, 18, 20, 22), each connected to a port (14a, 14b, 14c, 14n). Thus, N output ports can be provided.

[0029] An example of a 3D-printed multimode GNSS antenna (10) is shown in Figure 4. Here, the feed points (16, 18, 20, 22) are not only offset from each other in the horizontal direction h, but also in the vertical direction v. They are each connected to a port (14a, 14b, 14n-l, 14n). Such an antenna allows more degrees of freedom to avoid coupling between the individual ports.

[0030] The multimode GNSS antenna (10) according to the invention is preferably used in air traffic, for example in airplanes, helicopters, UAVs, eVTOL.

Claims

Claims 1. Multimode GNSS antenna (10) with an antenna element (12) for receiving signals from several satellites, characterized in that the multimode GNSS antenna (10) has at least two ports (14a-14n) which are connected to the antenna element (12) via at least one feed point (16-22).

2. Multimode GNSS antenna (10) according to claim 1, characterized in that each port (14a-14n) is connected to two feed points (16-22).

3. Multimode GNSS antenna (10) according to claim 1, characterized in that the multimode GNSS antenna (10) has at least three feed points (16-22) which are connected to at least two ports (14a-14n).

4. Multimode GNSS antenna (10) according to one of claims 1 to 3, characterized in that the multimode GNSS antenna (10) is designed as a microstrip patch antenna or dielectric resonator antenna.

5. Multimode GNSS antenna (10) according to one of claims 1 to 4, characterized in that the ports (14a-14n) are configured to receive signals with different polarizations, in particular vertical, horizontal, RHCP or LHCP polarization.

6. Multimode GNSS antenna (10) according to one of claims 1 to 5, characterized in that each feed point (16-22) is connected to exactly one port (14a-14n).

7. Multimode GNSS antenna (10) according to one of claims 1 to 6, characterized in that the multimode GNSS antenna (10) is provided by an additive manufacturing process, in particular 3D printing, and the feed points (16-22) are offset from each other in a vertical direction, so that they are located on different levels.

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