antenna

Abstract

The invention relates to an antenna having a housing (3), a core (1) and a coil (2) wound around the core (1), wherein the core (1) with the coil (2) is supported in the housing (3) in a potting compound (5), wherein the potting compound (5) is softer than Shore hardness A 40.

Description

TECHNICAL FIELD

[0001] The invention relates to an antenna, in particular to an antenna configured for transmitting key data for opening and / or starting a vehicle for use in a vehicle. BACKGROUND

[0002] Antennas are usually composed of a ferromagnetic core and a spule. The antennas are usually potted in a housing. The core and the spule have to be implemented in accordance with the transmission frequency and the bandwidth. The bandwidth of the antennas is becoming wider and wider (for example for UWB antennas) and the coverage of the antennas is becoming larger and larger, which for example leads to the fact that the cores also become longer and longer. But long cores are also more brittle than short cores and are more expensive in terms of manufacture.

[0003] It is therefore known, for example from the documents US10056687, EP1397845 and US2018 / 159224, to configure the core by means of a plurality of successively arranged sub-cores. This has the advantage that the manufacture of the individual sub-cores is simpler and the brittleness of the sub-cores is reduced. However, it has been shown that the magnetic properties of a core formed from a plurality of sub-cores are particularly susceptible to impacts or temperature fluctuations and that the antennas often have problems in terms of stability of the antenna properties.

[0004] It is in principle possible to use a softer potting mass, which better withstands impacts and thus reduces the brittleness. However, there are strict quality regulations for the positioning of the antenna components, which allow only small tolerances for the positioning of the antenna components in order not to impair the stability of the electrical properties of the antenna. The potting mass is therefore not selected to be too soft.

[0005] An alternative approach is pursued in the document US10062484. Here, a magnetic wire is placed in a non-magnetic soft mass and a flexible magnetic core is thus formed. However, the flexible magnetic core has worse magnetic properties than a conventional (stiff) magnetic core. SUMMARY

[0006] It is an object of the invention to find an antenna which is robust, easy in terms of manufacture and has good and stable antenna properties.

[0007] This object is achieved according to the invention in the antenna according to the independent claim and in the manufacturing method for such an antenna.

[0008] The use of potting compound 5 which is softer than Shore hardness A 40 (40 Shore A, sometimes referred to as 40 Shore hardness A) creates a very robust antenna due to the very good damping. Surprisingly, however, the antenna properties are also very stable. This can be due to the fact that in the case of a harder potting compound 5 a collision has led to damage to the potting compound 5 or the positioning device and thus to a permanent mispositioning of the antenna or antenna components. By using a very soft potting compound, a collision only leads to a very short movement of the antenna components in the potting compound and thereafter the antenna components are again brought back to the same original place. According to the application, short-term deviations from the predefined tolerances are accepted in order to improve the long-term stability of the antenna. Thus, a very robust antenna with very good electrical properties is created by a very soft potting compound.

[0009] Alternatively, the object is additionally achieved by an antenna with one or a combination of the following features, which has a core and a coil wound around the core. The antenna can also have no potting compound or a harder potting compound.

[0010] Further advantageous embodiments are specified in the dependent claims.

[0011] In one embodiment, the potting compound is softer than Shore hardness A 35, preferably softer than Shore hardness A 30, preferably softer than Shore hardness A 27, preferably softer than Shore hardness A 25. These hardnesses of the potting compound result in much better values for the stability of the breakage and the stability of the electrical values. In one embodiment, the potting compound is harder than Shore hardness A 10, preferably harder than Shore hardness A 15. In the region of greater than Shore hardness A 10 or 15, an optimum value between the breakage stability and the electrical stability is achieved.

[0012] In an embodiment, the core has a plurality of sub-cores, wherein the plurality of sub-cores has a first sub-core and a second sub-core. The plurality of sub-cores simplifies the manufacturing of the core and improves its breakage stability. A soft potting compound is especially advantageous for embodiments with sub-cores. It was found that a soft potting compound leads to a less influenced relative position of the two sub-cores after a crash and thus to a less influenced electrical parameter of the antenna. In an embodiment, the first sub-core is arranged with a distance to the second sub-core. This proves to be especially advantageous in combination with a soft potting compound. The soft potting compound allows a certain play of movement of the sub-cores when subjected to a crash. When the sub-cores are now touching each other, the crash is transmitted from the first sub-core to the second sub-core and thus the breakage probability of the sub-cores can be increased again despite the soft potting compound. This is avoided by a gap between the sub-cores. In case the sub-cores touch each other, the magnetic properties of the whole core are very strongly dependent on the force with which the two sub-cores push against each other. Due to the soft potting compound the pressing force of the two sub-cores can be strongly varied and even lead to a separation of the sub-cores. This variation of the pressing force can be caused by vibrations, crashes or changes in temperature. This leads to a large electrical instability of the antenna, which is not desired. It is therefore especially advantageous in case a soft potting compound is used in combination with a plurality of sub-cores to use a gap between the sub-cores. The thermal and electrical stability of the antenna is thereby significantly improved. In an embodiment, the gap formed by the distance is filled by the potting compound. The potting compound between the sub-cores thus also acts as a damper and furthermore very well leads the heat between the sub-cores out into the remaining potting compound.

[0013] In an embodiment, the first sub-core has a first longitudinal axis and the second sub-core has a second longitudinal axis. In an embodiment, the first sub-core and the second sub-core are arranged such that the second longitudinal axis extends in an extension of the first longitudinal axis. In an embodiment, the first sub-core has a first cross section perpendicular to the first longitudinal axis and the second sub-core has a second cross section perpendicular to the second longitudinal axis. In an embodiment, the second cross section corresponds to the first cross section. In an embodiment, the first sub-core and the second sub-core are arranged such that the first cross section is arranged flush with the second cross section. In an embodiment, the first sub-core has the same first cross section along the whole first longitudinal axis. In an embodiment, the second sub-core has the same second cross section along the whole second longitudinal axis.

[0014] In an embodiment, the first sub-core has a first end and a second end opposite to the first end. In an embodiment, the second sub-core has a first end and a second end opposite to the first end. In an embodiment, the first end of the first sub-core is arranged to face the first end of the second sub-core.

[0015] In an embodiment, the antenna has a core holder. The core holder allows certain movements of the core which are not desired for electrical stability and allows other movements which are desired for electrical stability and break stability. In an embodiment, the core holder supports the first and the second sub-core. The core holder is especially advantageous for embodiments with two sub-cores, especially with two sub-cores having a gap, because the core holder is beneficial in otherwise complex positioning.

[0016] In an embodiment, the core holder extends from the second end of the first sub-core to the second end of the second sub-core (excluding possible protruding ends of the sub-cores, for example up to 10% of the length of the core 1, preferably up to 5%). This allows a stable holding of the sub-cores over the length of the core 1.

[0017] In an embodiment, the coil is wound onto the core holder. This has the advantage that the sub-cores are held stably during the winding of the coil. In an embodiment, the coil is wound such that the coil extends over 80% of the length between the second ends of the sub-cores.

[0018] In an embodiment, before the sub-cores, the core holder and the coil are potted in the housing with potting compound, the core holder is configured to push the first sub-core and / or the second sub-core into the core holder in the direction of the longitudinal axis of the respective sub-core for mounting.

[0019] In an embodiment, before the sub-cores, the core holder and the coil are potted in the housing with potting compound, the core holder with the mounted sub-cores and the coil is configured to move the first sub-core and / or the second sub-core in the direction of the longitudinal axis of the respective sub-core.

[0020] In an embodiment, before the sub-cores, the core holder and the coil are potted in the housing with potting compound, the core holder with the mounted sub-cores and the coil is configured to fix the first sub-core and / or the second sub-core perpendicular to the direction of the longitudinal axis of the respective sub-core.

[0021] In an embodiment, the position of the core holder, the coil, the first sub-core and / or the second sub-core in the housing is fixed by the potting compound.

[0022] In an embodiment, the antenna is configured for use in a vehicle and / or for transmitting key data for opening and / or starting the vehicle.

[0023] In an embodiment, the vehicle has the antenna described before. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application is further explained according to the drawings, in which:

[0025] Figure 1A 3D view of the first embodiment of the antenna with cut open housing and potting is shown.

[0026] Figure 2 A 3D view of the first embodiment of the antenna without housing and potting is shown.

[0027] Figure 3 A 3D view of the first embodiment of the antenna without core holder, housing and potting is shown.

[0028] Figure 4 A first sectional view through the antenna according to the first embodiment is shown.

[0029] Figure 5 A top view of the antenna according to the first embodiment is shown.

[0030] Figure 6 A second sectional view through the antenna according to the first embodiment along line D-D is shown.

[0031] Figure 7 A third sectional view through the antenna according to the first embodiment along line E-E is shown.

[0032] Figure 8 An enlarged view of section F from Figure 1 is shown. DETAILED DESCRIPTION

[0033] Figures 1 to 8 An embodiment of the present application is shown.

[0034] The antenna has a core 1, a coil 2, a housing, a core holder 4 and a potting 5.

[0035] The core 1 is a magnetic core. The core 1 preferably extends along a longitudinal axis. Preferably, the core 1 is longer in the direction of the longitudinal axis than in other (perpendicular to the longitudinal axis) directions / axes. The core 1 is made of a magnetic material. Preferably, the core is made of a ferrite material (ferrite material) or a powder material (powder core), e.g. a ferrite material. By magnetic material is meant that the material is at least paramagnetic, preferably ferromagnetic. The magnetic core 1 is made of a hard material, that is to say the magnetic core 1 is inelastic or non-bendable. The magnetic core 1 preferably has a rectangular cross section.

[0036] Preferably, the magnetic core consists of a plurality of sub-cores 1.1 and 1.2. The above described material properties of the core 1 apply accordingly to each sub-core 1.1, 1.2. Preferably, the same magnetic material is used for the different sub-cores 1.1 and 1.2. The plurality of sub-cores 1.1 and 1.2 has at least two sub-cores 1.1 and 1.2 with a first sub-core 1.1 and a second sub-core 1.2. The first sub-core has a first longitudinal axis. The second sub-core has a second longitudinal axis. The first sub-core 1.1 and the second sub-core 1.2 are preferably arranged such that the second longitudinal axis extends in the prolongation of the first longitudinal axis (so that the first and second longitudinal axis constitute the longitudinal axis of the core 1). This means that the first and second longitudinal axis are arranged without crossing each other, at 0° or 180° and / or parallel / coaxial / overlapping each other. The first sub-core 1.1 has a first end and a second end (in the direction of the first longitudinal axis) opposite the first end. The second sub-core 1.2 has a first end and a second end (in the direction of the second longitudinal axis) opposite the first end. The first end of the first sub-core 1.1 is preferably arranged to face the first end of the second sub-core 1.2. The second end of the first sub-core 1.1 thus constitutes the first end of the core 1 and the second end of the second sub-core 1.2 constitutes the second end of the core 1, provided that the core 1 consists of two sub-cores 1.1, 1.2. The first sub-core 1.1 has a first cross-section perpendicular to the first longitudinal axis. The second sub-core 1.2 has a second cross-section perpendicular to the second longitudinal axis. Preferably, the second cross-section corresponds to the first cross-section. Preferably, the first sub-core 1.1 and the second sub-core 1.2 are arranged such that the first cross-section of the first sub-core 1.1 is arranged flush with the second cross-section of the second sub-core 1.2. This should mean that the second sub-core 1.2 constitutes the prolongation of the first sub-core 1.1 in the first or second longitudinal axis, wherein both sub-cores 1.1 have coaxially arranged longitudinal axes and identical cross-sections (which in the case of a non-rotationally symmetrical cross-section are arranged such that the cross-sections completely overlap). Preferably, the first sub-core 1.1 has the same first cross-section along the entire first longitudinal axis. Preferably, the second sub-core 1.2 has the same second cross-section along the entire second longitudinal axis. Preferably, the first sub-core 1.1 and the second sub-core 1.2 are identical, so that the same parts can be used for both sub-cores 1.1, 1.2. Preferably, the first sub-core 1.1 is arranged with a spacing to the second sub-core 1.2. Thereby a gap is created between the first sub-core 1.1 and the second sub-core 1.2. The spacing between the first sub-core 1.1 and the second sub-core 1.2 is preferably larger than 0.1 mm, preferably larger than 0.3 mm, preferably larger than 0.5 mm, preferably larger than 1 mm. The gap is preferably smaller than 10 mm, preferably smaller than 7 mm, preferably smaller than 5 mm, because a too large gap can negatively influence the magnetic field lines between the two sub-cores 1.1, 1.2.

[0037] The coil 2 is wound around the core 1. The coil 2 preferably has a plurality of turns around the core 1, preferably with more than two, preferably with more than five, preferably with more than ten, preferably with more than fifteen, preferably with more than twenty turns. The coil 2 preferably extends from the first end of the core 1 or the second end of the first sub-core 1.1 to the second end of the core 1 or the second end of the second sub-core 1.2, such that the area between the last turn of the coil 2 in the direction of the first end of the core 1 or the second end of the first sub-core 1.1 and the last turn of the coil 2 in the direction of the second end of the core 1 or the second end of the second sub-core 1.2 amounts to at least 70%, preferably at least 75%, preferably at least 80% of the longitudinal extension of the core 1 or of the two sub-cores 1.1, 1.2. Preferably, the coil 2 extends over both sub-cores 1.1, 1.2. The coil 2 preferably extends over both sub-cores 1.1, 1.2. Preferably, the coil 2 or the coil wire of the coil 2 is wound onto the core holder 4. However, it is also possible to wind the coil 2 or the coil wire directly onto the core 1 (without the core holder 4). The coil 2 preferably has a coil wire which is wound around the core 1 or the core holder 4. The coil wire is preferably insulated. However, the coil wire can also be uninsulated. However, care must be taken when winding that the wires do not touch one another and also do not touch the core 1 when crossing. Preferably, the coil wire is wound such that both ends of the coil wire are connected to the interfaces of the antenna at the ends of the core 1. In the embodiment shown, the coil 2 is wound in one direction from the first end of the core 1 to the second end of the core 1 and the coil wire is then led back from the second end of the core 1 to the first end of the core 1 (without turns around the core 1). However, it is also possible to first lead the coil wire from the first end of the core 1 to the second end of the core 1 (without turns around the core 1) and then to wind in one direction from the second end of the core 1 to the first end of the core 1. It is also possible to wind the coil wire in both directions (cross winding).

[0038] The core holder 4 is configured for supporting / holding the core 1. This is especially important for mounting the antenna before potting, so that all antenna components are held in the correct position before the antenna is potted. The features of the core holder 4 described below thus relate to the state before the antenna is potted, if this is not explicitly described otherwise. The core holder 4 is preferably configured to support the coil 2. Preferably, the core holder 4 has an inner opening in which the core 1 is held. Preferably, the core holder 4 has an outer face on which the coil 2 is wound. The core holder 4 is especially advantageous for embodiments with multiple sub-cores 1.1, 1.2. The core holder 4 preferably fixes the position of the sub-cores 1.1, 1.2 to each other at least in one direction. Preferably, the core holder 4 fixes the position of the sub-cores 1.1, 1.2 such that they are perpendicular to the longitudinal axis of the core 1 or the sub-cores 1.1, 1.2 (radially at least in one direction, preferably in all directions of 330°, preferably 350°, preferably radially in all directions around the longitudinal axis). Preferably, at least one (or both) of the two sub-cores 1.1, 1.2 can move in the direction of the longitudinal axis when both sub-cores 1.1, 1.2 are mounted in the core holder 4 and the coil 2 is wound around the core 1 on the core holder 4. Thus, it is also possible to fine-tune the mounted antenna before potting by adjusting the distance between the two sub-cores 1.1, 1.2 such that the desired antenna characteristics are met. However, it is also possible that the two sub-cores 1.1, 1.2 are completely fixed in their position so that the sub-cores 1.1, 1.2 cannot move their position (absolute and / or relative to each other). Preferably, the sub-cores 1.1, 1.2 are introduced for mounting in the direction of the longitudinal axis of the core 1 or the sub-cores 1.1, 1.2. This allows that the sub-cores 1.1, 1.2 can be stably positioned relative to each other and still be able to move axially relative to each other. However, it is also possible to introduce the sub-cores 1.1, 1.2 in the core holder 4 in another way. Preferably, the core holder 4 extends from the second end of the first sub-core to the second end of the second sub-core. This allows a stable holding of the sub-cores 1.1, 1.2. This is advantageous for positioning during manufacturing and also stabilizes the potted sub-cores 1.1, 1.2 later in use. In the shown embodiment the core holder 4 has at least one, preferably two parallel longitudinal holders 41 which extend in the direction of the longitudinal axis of the core 1. Preferably, the core holder 4 has a plurality of lateral holders 42 which inhibit / impede a movement of the sub-cores 1.1, 1.2 in radial direction relative to the longitudinal axis of the core 1. In the area of the lateral holders 42 the winding of the coil 2 is preferably interrupted. Preferably, the lateral holders 42 are connected to two longitudinal holders 41, respectively. For the description the four side edges of the core 1 (perpendicular to the longitudinal axis of the core 1) are referred to as upper side edge (or first side edge), lower side edge (or second side edge) and two lateral side edges (third side edge and fourth side edge), but the application is not limited to a specific orientation of the antenna thereby.Preferably, the upper side and the lower side are opposite and / or the two lateral sides are opposite. Preferably, there is an upper cross support 42 at which the upper side of the core 1 rests. Preferably, there is a lower cross support 42 at which the lower side of the core 1 rests. Preferably, two longitudinal supports are arranged at the two lateral sides of the core 1 so that the two lateral sides of the core 1 rest at the two longitudinal supports. The core support 4 preferably has a closing area 43 at one end which is configured to close the opening of the housing 3 when the core support 4 (with the core 1 and the coil 2) is mounted into the housing 3. The closing area 43 can here be integrally manufactured from one piece with the remaining core support 4. It is also possible, however, that the closing area 43 is assembled together with the remaining core support 4 from separate parts. The closing area 43 preferably has an interface for the electrical connection of the antenna, in particular the coil 2. Preferably, the interface has two electrically conductive pins which extend through the closing area 43. One side of each of the conductive pins here projects out of the closing area 43 on the outside so that the finished antenna can be electrically connected. The opposite side of each of the conductive pins projects on the inside of the closing area 43, wherein the ends of the coil 2 or coil wire are respectively connected to one of the conductive pins (on the inside). The core support 4 is preferably configured so that the core support 4 has a predefined position after being mounted in the housing 3. This is achieved on one side of the antenna, for example, by the closing area 43 being positioned in the opening of the housing 3. The core support 4 preferably has in addition a positioning device 44 which holds the core support 4 in the predefined position when the core support 4 is mounted in the housing 3. The positioning device 44 is preferably arranged on the area of the core support 4 opposite the closing area 43. Preferably, the positioning device 44 is resilient so that the positioning device 44 defines the predefined position but allows a deviation from the predefined position in the case of vibrations or impacts. Preferably, the positioning device 44 has a bendable / resilient arm 44 which presses against the inner wall of the housing 3 and thus brings the core support 4 into the predefined position in the housing 3. This is shown in the cross sections D-D and E-E in Figure 6 and 7 The core support 4 is preferably manufactured from plastic.

[0039] The housing 3 is configured to enclose the core 1 with the coil 2. Preferably, the housing 3 is configured to enclose the core support 4 with the core 1 and the coil 2. The housing 3 preferably has an opening which is configured to introduce the core 1 with the coil 2 or the core support 4 with the core 1 and the coil 2 into the housing 3. Preferably, the opening is closed by the core support 4 in the introduced state. It is also possible, however, that the opening is closed by a separate cover.

[0040] A potting compound 5 is arranged between the housing 3 and the core 1 with the coil 2 or the core support 4 with the core 1 and the coil 2. The core 1 with the coil 2 or the core support 4 with the core 1 and the coil 2 is introduced into the housing 3 and is potted therein with the potting compound 5. The potting compound 5 is also often referred to as encapsulation compound. The potting compound 5 preferably fills the preferably entire cavity in the housing 3, so that the heat of the core 1 and the coil 2 is effectively dissipated and the core 1 with the coil 2 or the core support 4 with the core 1 and the coil 2 is stably supported. According to the application a potting compound 5 is used which is softer than Shore A 40, preferably softer than Shore A 35, preferably softer than Shore A 30, preferably softer than Shore A 27, preferably softer than Shore A 25 (in the hardened state). It has been found that a potting compound 5 which is softer than Shore A 40 or the mentioned preferred values not only improves the breaking stability, but surprisingly also the stability of the electrical values of the antenna. However, the potting compound 5 is preferably harder than Shore A 10, preferably harder than Shore A 15 (in the hardened state). A potting compound 5 with a deformation between Shore A 10 and 40 has been found to be particularly advantageous.

[0041] To manufacture the antenna first the core 1 possibly with the sub-cores 1.1, 1.2 is mounted into the core support 4. The coil 2 is wound onto the core support 4 or the core 1. The coil wire is connected to the interfaces of the antenna. The core 1 with the coil 2 or the core support 4 with the core 1 and the coil 2 is introduced into the housing 3. The core 1 with the coil 2 or the core support 4 with the core 1 and the coil 2 is potted in the housing 3 with the potting compound 5. Thereafter the potting compound 5 is hardened and the antenna is finished.

Claims

1. Antenna having a housing (3), a core (1) and a coil (2) wound around the core (1), wherein The core (1) with the coil (2) is supported in the housing (3) in a potting compound (5); It is characterized in that The potting compound (5) is softer than Shore hardness A 40, Wherein the core (1) has a plurality of sub-cores (1.1, 1.2), wherein the plurality of sub-cores (1.1, 1.2) has a first sub-core (1.1) and a second sub-core (1.2), wherein the antenna has a core holder (4), wherein the first sub-core (1.1) and the second sub-core (1.2) are held in the core holder (4), wherein the core holder (4) has a positioning device (44), which holds the core holder (4) in a predefined position when the core holder (4) is mounted in the housing (3), wherein the positioning device (44) has elastic arms, which press against the inner wall of the housing (3) and thus bring the core holder (4) into a predefined position in the housing (3).

2. The antenna according to the preceding claim, wherein, The potting compound (5) is softer than Shore hardness A 30.

3. The antenna according to claim 1 or 2, wherein, The first sub-core (1.1) has a first longitudinal axis and the second sub-core (1.2) has a second longitudinal axis, wherein the first sub-core (1.1) and the second sub-core (1.2) are arranged such that the second longitudinal axis extends in the prolongation of the first longitudinal axis.

4. The antenna of claim 3, wherein, The first sub-core (1.1) has a first cross section perpendicular to the first longitudinal axis, wherein the second sub-core (1.2) has a second cross section perpendicular to the second longitudinal axis, which second cross section corresponds to the first cross section, wherein, The first sub-core (1.1) and the second sub-core (1.2) are arranged such that the first cross section is arranged flush with the second cross section, and / or The first sub-core (1.1) has the same first cross section along the entire first longitudinal axis, and / or the second sub-core (1.2) has the same second cross section along the entire second longitudinal axis.

5. The antenna of claim 3, wherein, The first sub-core (1.1) is arranged with a spacing to the second sub-core (1.2), and the gap formed by the spacing is filled by the potting compound (5).

6. The antenna of claim 1, wherein, The first sub-core (1.1) has a first end and a second end opposite the first end, wherein the second sub-core (1.2) has a first end and a second end opposite the first end, wherein the first end of the first sub-core (1.1) is arranged to face the first end of the second sub-core (1.2), wherein the core holder (4) extends from the second end of the first sub-core (1.1) to the second end of the second sub-core (1.2).

7. The antenna of claim 1, wherein, The coil is wound onto the core holder.

8. The antenna of claim 1, wherein, Before the sub-cores (1.1, 1.2), the core holder (4) and the coil (2) are potted in the housing (3) with the potting compound (5), the core holder (4) with the mounted sub-cores (1.1, 1.2) and the coil (2) is configured to move the first sub-core (1.1) and / or the second sub-core (1.2) in the direction of the longitudinal axis of the respective sub-core (1.1, 1.2).

9. The antenna of claim 1, wherein, Before the sub-cores, the core holder and the coil are potted in the housing with the potting compound (5), the core holder with the mounted sub-cores and the coil is configured to fix the first sub-core (1.1) and / or the second sub-core (1.2) in the direction perpendicular to the longitudinal axis of the respective sub-core.

10. The antenna of claim 1, wherein, The position of the core holder (4), the coil (2), the first sub-core (1.1) and / or the second sub-core (1.2) in the housing (3) is fixed by the potting compound (5).

11. Antenna according to claim 1 or 2 for use in a vehicle configured for transmitting key data for opening and / or starting the vehicle.

12. The antenna of claim 7, wherein, The coil is wound onto the core holder such that the coil extends over more than 80% of the length between the second end portions of the sub-cores.

13. Vehicle having an antenna according to claim 1.

14. Method for manufacturing an antenna, the method having the steps of: potting a core (1) with a coil (2) wound thereon in a housing (3) with a potting compound (5); hardening the potting compound (5); characterized in that the hardened potting compound (5) is softer than Shore hardness A 40, wherein the core (1) has a plurality of sub-cores (1.1, 1.2), wherein the plurality of sub-cores (1.1, 1.2) has a first sub-core (1.1) and a second sub-core (1.2), wherein the antenna has a core holder (4), wherein the first sub-core (1.1) and the second sub-core (1.2) are held in the core holder (4), wherein the core holder (4) has a positioning device (44) which holds the core holder (4) in a predefined position when the core holder (4) is mounted in the housing (3), wherein the positioning device (44) has a resilient arm which presses against an inner wall of the housing (3) and thus brings the core holder (4) into a predefined position in the housing (3).

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