ANTENNA

Description

Technical field

[0001] The invention relates to an antenna, in particular an antenna for use in a vehicle designed for the transmission of key data for opening and / or starting the vehicle. State of the art

[0002] Antennas typically consist of a core and a coil. The core and coil must be designed accordingly, depending on the transmission frequency and bandwidth. Antenna bandwidths are constantly increasing, for example with UWB antennas, and antenna ranges are also increasing, which, for instance, means that cores are becoming longer. However, long cores are also more prone to breakage than shorter cores and more complex to manufacture.

[0003] Therefore, it is now known to construct the core using a plurality of sub-cores arranged one behind the other, e.g., in US10056687, EP1397845, US2018 / 159224, DE102016010493, US2018 / 0122551. Solutions are also known, e.g., DE202015107067, US2004 / 0252068, WO2017 / 108227, in which the antenna is constructed with sub-cores arranged one above the other, partially overlapping. This has the advantage that the production of the individual sub-cores is simpler and their susceptibility to breakage is reduced. However, it has been shown that the magnetic properties of the core formed from several sub-cores are very susceptible to shocks or temperature fluctuations, and these antennas often have problems with the stability of their antenna characteristics. The subcores are arranged one behind the other, either with a gap or in contact.If the subcores are in contact, their magnetic properties fluctuate with the contact pressure between them, which can vary depending on temperature or vibrations. If the subcores are spaced apart, this distance often varies depending on temperature or external forces, which in turn negatively affects the electrical properties of the core and thus the antenna. Therefore, it has not yet been possible to create a high-quality antenna with multiple subcores. Description of the invention

[0004] One aim of the invention is to find an antenna that is robust, easy to manufacture, and has good and stable antenna characteristics.

[0005] According to the invention, this objective is achieved in an antenna and a manufacturing method for such an antenna according to the independent claims.

[0006] The use of at least one second sub-core, which laterally overlaps two of the at least two first sub-cores, allows for a magnetic bridging of the contact point or gap between the first sub-cores. This makes the core independent of the contact pressure or gap size between the first sub-cores and thus independent of temperature fluctuations, vibrations, and other external influences. Simultaneously, the core can be formed from multiple sub-cores, which simplifies manufacturing and is advantageous for the core's fracture stability.

[0007] Further advantageous embodiments are specified in the dependent claims. Brief description of the characters

[0008] The invention is explained in more detail with reference to the accompanying figures, which show Fig. 1 A first side view of an antenna according to a first embodiment of the invention. Fig. 2A second side view of the antenna according to the first embodiment. Fig. 3 A sectional view along line AA of the antenna according to the first embodiment. Fig. 4 a sectional view along line BB of the antenna according to the first embodiment. Fig. 5 a sectional view along line CC of the antenna according to the first embodiment. Fig. 6 A sectional view along line DD of the antenna according to the first embodiment. Fig. 7 a sectional view along the line EE of the antenna according to the first embodiment. Fig. 8 a 3D view of an antenna according to a second embodiment of the invention with a partially cut-open housing and potting material. Fig. 9 A first side view of the antenna according to the second embodiment. Fig. 10 a sectional view along line BB of the antenna according to the second embodiment. Fig. 11A sectional view along line AA of the antenna according to the second embodiment. Fig. 12 A sectional view along line CC of the antenna according to the second embodiment. Fig. 13 A sectional view along line DD of the antenna according to the second embodiment. Ways to implement the invention

[0009] Figs. 1 to 7 show a first embodiment of the invention. Figs. 8 to 13 Figure 1 shows a second embodiment of the invention. Both embodiments are described together below. If the first and second embodiments differ in any feature, this will be explicitly mentioned. Otherwise, all described features apply to both embodiments.

[0010] In the following description, three orthogonal directions are used: a first direction 7, a second direction 8, and a third direction 9. The first direction 7 is preferably orthogonal to the second direction 8 and the third direction 9. The second direction 8 is preferably orthogonal to the first direction 7 and the third direction 9. The third direction 9 is preferably orthogonal to the first direction 7 and the second direction 8.

[0011] The antenna comprises a core 1 and a coil 2. Preferably, the antenna further comprises a housing 3, a core support 4, and a potting compound 5.

[0012] Core 1 is a magnetic core. Core 1 is made of a magnetic material. Magnetic material means that the material is paramagnetic or ferromagnetic, preferably ferromagnetic. Preferably, core 1 is made of a ferrite material (ferrite material) or a powder material (powder core). The magnetic core 1 is preferably made of a rigid magnetic material, i.e., the magnetic core 1 is not elastic or flexible.

[0013] The core 1 preferably extends along the first direction 7. The first direction is therefore also referred to as the longitudinal direction 7 of the core 1. The longitudinal axis of the core 1 thus extends in the first direction 7. Preferably, the core 1 is longer in the longitudinal direction 7 than in the second direction 8 and the third direction 9. In one embodiment, the core 1 is larger in the second direction 8 (width) than in the third direction 9 (thickness or height). In another embodiment, the core 1 is the same size in the second direction 8 and in the third direction.

[0014] According to the invention, the core 1 has at least two first subcores 1.1 and at least one second subcore 1.2. In the first embodiment, the core 1 has five first subcores 1.1 and four second subcores 1.2. In the second embodiment, the core 1 has four first subcores 1.1 and three second subcores 1.2. However, the number is arbitrary and can be varied as desired depending on the length of the core 1 and the lengths of the subcores 1.1 and 1.2. Preferably, the core 1 has n first subcores 1.1 and n-1 or n second subcores 1.2, where n is equal to or greater than two.

[0015] The magnetic material of core 1, as previously described, corresponds to the magnetic material of subcores 1.1 and 1.2. Preferably, all subcores 1.1 and 1.2 have the same magnetic material. However, it is also possible to use different magnetic materials in different subcores 1.1 and 1.2.

[0016] The first subcores 1.1 have a longitudinal axis extending in the longitudinal direction 7. Preferably, the first subcores 1.1 are longer in the longitudinal direction 7 than in the second direction 8 and / or than in the third direction 9. Preferably, the first subcores 1.1 have a lateral side. Preferably, the lateral side is arranged parallel to the longitudinal direction 7. Preferably, the orthonormal vector of the lateral side of the first subcores 1.1 is parallel to the second direction 8 or to the third direction 9. Preferably, the lateral side forms a planar surface. The first subcores 1.1 preferably have a first axial side and a second axial side opposite the first axial side. The first and / or second axial side is preferably perpendicular to the lateral side or to the longitudinal axis 7 of the respective first subcore 1.1. Preferably, the first and second axial sides are arranged parallel to each other.Preferably, the first and / or second axial side forms a flat surface. Preferably, the first subcores 1.1 each have a rectangular cross-section. Preferably, the lateral side of all first subcores 1.1 is identical. However, other cross-sectional shapes, such as triangular, semicircular, etc., are also conceivable. Preferably, the cross-sectional shape of the first subcores 1.1 is constant / identical along the longitudinal direction 7 of the first subcore 1.1. Preferably, all first subcores 1.1 have the same cross-sectional shape. The cross-sectional shape of the first subcore 1.1 is defined as the cross-section perpendicular to the longitudinal direction 7. Preferably, the first subcores 1.1 are cuboidal, i.e., with six sides arranged at right angles to each other. Preferably, all first subcores 1.1 have the same shape.

[0017] The second subcores 1.2 have a longitudinal axis extending in the longitudinal direction 7. Preferably, the second subcores 1.2 are longer in the longitudinal direction 7 than in the second direction 8 and / or than in the third direction 9. Preferably, the second subcores 1.2 have a lateral side. Preferably, the lateral side is arranged parallel to the longitudinal direction 7 and / or parallel to the parallel side of the first subcores 1.1. Preferably, the orthonormal vector of the lateral side of the second subcores 1.2 is parallel to the second direction 8 or to the third direction 9 or to the orthonormal vector of the lateral side of the first subcores 1.1. Preferably, the shape of the lateral side of the second subcores 1.2 corresponds to the shape of the lateral side of the first subcores 1.1, so that the lateral side of the second subcores 1.2 can rest (over its entire surface) on the lateral sides of the first subcores 1.1.Preferably, the lateral side forms a flat surface. The second sub-cores 1.2 preferably have a first axial side and a second axial side opposite the first axial side. The first and / or second axial side is preferably perpendicular to the lateral side or to the longitudinal axis 7 of the respective second sub-core 1.2. Preferably, the first and second axial sides are arranged parallel to each other. Preferably, the first and / or second axial side forms a flat surface. Preferably, the second sub-cores 1.2 each have a rectangular cross-section. Preferably, the lateral side of all second sub-cores 1.2 is identical. However, other cross-sectional shapes, such as triangular, semicircular, etc., are also conceivable. Preferably, the second sub-cores 1.2 have the same cross-sectional shape as the first sub-cores 1.1. Preferably, the cross-sectional shape of the second sub-cores 1.1 is...2 constant / uniform along the longitudinal direction 7 of a subcore 1.2. Preferably, all second subcores 1.2 have the same cross-sectional shape. The cross-sectional shape of the second subcore 1.2 is defined as the cross-section perpendicular to the longitudinal direction 7. Preferably, the second subcores 1.2 are cuboid, i.e., with six sides arranged at right angles to each other. Preferably, all second subcores 1.2 have the same shape. Preferably, the second subcores 1.2 are shaped like the first subcores 1.1 (see first embodiment). However, it is also possible for the first and second subcores 1.1, 1.2 to have different shapes (see second embodiment with different lengths of the first and second subcores 1.1, 1.2). Preferably, the second subcores 1.2 are identical to the first subcores 1.1. This allows the same subcores to be used for the first and second subcores 1.1 and 1.2.2. However, it can also be advantageous to use different subcores for the first subcores 1.1 and the second subcores 1.2. For example, different magnetic materials could be used. The second subcores 1.2 could have a higher permeability than the first subcores 1.1. This allows the high permeability to be used only for the bridge function, while a simpler (and cheaper) magnetic material with a lower magnetic permeability is chosen for the first subcores 1.1, which contain the majority of the magnetic material. Here, the second subcores 1.2 have been described in the plural. The description naturally also applies to an embodiment with only one second subcore 1.2.

[0018] The first subcores 1.1 are preferably arranged one behind the other in the longitudinal direction 7. Preferably, the first subcores 1.1 are arranged one behind the other such that the longitudinal axes of the first subcores 1.1 are arranged coaxially, i.e., the longitudinal axes of the first subcores 1.1 form the respective extensions of the adjacent first subcores 1.1. Preferably, the first axial side of a first first subcore 1.1 is arranged opposite a first axial side of a second first subcore 1.1. Preferably, the first subcores 1.1 are arranged one behind the other such that the first axial side of the first first subcore 1.1 completely overlaps with the first axial side of the second first subcore 1.1, i.e., the axial side of the first first subcore 1.1 overlaps the axial side of the second first subcore 1.1 and / or the axial side of the second first subcore 1.1 overlaps the axial side of the first first subcore 1.1.In other words, a first subcore 1.1 represents a longitudinal extension 7 of the adjacent first subcore 1.1. In one embodiment, the first subcores 1.1 are arranged with a distance between their axial sides. In another embodiment, the axial sides of the first subcores 1.1 are in contact (see first and second embodiments). Due to the magnetic bridge provided by the second subcores 1.2, as described below, it is magnetically irrelevant whether the first subcores 1.1 are in contact or spaced apart. The distance can therefore be chosen to be large, e.g., to save material.

[0019] According to the invention, a first second subcore 1.2 is arranged such that the lateral side of the first second subcore 1.2 overlaps at least a portion of the lateral side of a first first subcore 1.1 and at least a portion of the lateral side of a second first subcore 1.1. This means that a projection of the first second subcore 1.2 perpendicular to the longitudinal axis 7 onto the first first subcore 1.1 intersects it, and that a projection of the first second subcore 1.2 perpendicular to the longitudinal axis 7 onto the second first subcore 1.1 intersects it. Preferably, the lateral side of the first second subcore 1.2 overlaps the lateral side of the first first subcore 1.1 by at least a minimum overlap length and the lateral side of the second first subcore 1.1 by at least a minimum overlap length.The minimum overlap length is at least one percent, preferably at least two percent, of the shortest subcore (in longitudinal direction 7) of the first subcore 1.1, the second subcore 1.1, and the first subcore 1.2, preferably of the shortest subcore 1.1, 1.2 (in longitudinal direction 7). This forms a magnetic bridge at the contact point between the two first subcores 1.1 connected in series, which eliminates fluctuations due to temperature and external influences at the interface between the two first subcores 1.1. Preferably, however, the overlap length is longer for stability reasons. Preferably, the first subcores 1.1 are arranged in a first plane and the at least one second subcore 1.2 is arranged in a second plane. The second plane is preferably parallel to the first plane. In one embodiment, the first plane and / or the second plane is perpendicular to the second direction 8, i.e.,The first subcores 1.1 and the at least one second subcore 1.2 are stacked in the second direction 8 (see the second embodiment with the stacking direction in the second direction 8). In one embodiment, the first plane and / or the second plane is perpendicular to the third direction 9, i.e., the first subcores 1.1 and the at least one second subcore 1.2 are stacked in the third direction 9 (see the first embodiment with the stacking direction in the third direction 9). However, the stacking direction could also be a linear combination of the second and third directions 8 and 9. Preferably, the projection of the first second subcore 1.2 in the direction perpendicular to the stacking direction and to the longitudinal direction 7 does not overlap the first first subcore 1.1 and / or the second first subcore 1.1, and / or the projection of the first first subcore 1.1 does not overlap.1 in the direction perpendicular to the stacking direction and the longitudinal direction 7 does not include the first second sub-core 1.2. In the first embodiment, this is the projection in the second direction 8, and in the second embodiment, it is the projection in the third direction 9. However, embodiments are also conceivable in which such an overlap exists. For example, two L-shaped cross-sections could be placed on top of each other, so that there are two stacking directions, e.g., the second and third directions 8 and 9. In this embodiment, the first sub-cores 1.2 and the second sub-cores 1.1 each have an L-shaped or angled cross-section. The cross-section of the combined first and second sub-cores 1.1 and 1.2 in an overlap area then again results in a rectangular cross-section. Preferably, the first sub-cores 1.1 and the at least one second sub-core 1.2 are designed such that the first sub-cores 1.The first sub-core 1.1 and the at least one second sub-core 1.2 can be stacked, or are stacked, perpendicular to the longitudinal axis 7. However, it would also be conceivable to insert the at least one second sub-core 1.2 longitudinally into an axial opening in the longitudinal direction 7 in the first sub-core 1.1. But this is rather complex to manufacture and also negatively affects the risk of breakage. The lateral side of the second sub-core 1.2 preferably contacts the lateral sides of the first sub-core 1.1 and the second sub-core 1.1. The longitudinal axis of the at least one second sub-core 1.2 is preferably arranged parallel to the longitudinal axis of the at least two first sub-cores 1.1. Preferably, the lateral side of the at least one second sub-core 1.2 is arranged parallel to the lateral sides of the at least two first sub-cores 1.1.Preferably, the cross-section of the core 1 (perpendicular to the longitudinal axis 7) in the overlap area of ​​one of the at least one second sub-core 1.2 and one of the at least two first sub-cores 1.1 is rectangular. Preferably, this rectangular cross-section of the core 1 is formed by rectangular cross-sections of the corresponding first and second sub-cores 1.1 and 1.2. However, it would also be possible to form the rectangular cross-section of the core 1 from triangular, L-shaped, or other cross-sections of the first and second sub-cores 1.1 and 1.2.

[0020] If core 1 has two or more second subcores 1.2, the following preferably applies to the arrangement of the second subcores 1.2. In this case, there is at least one second second subcore 1.2. The second first subcore 1.1 is arranged such that the lateral side of the second first subcore 1.1 overlaps at least a portion of the lateral side of the first second subcore 1.2 and at least a portion of the lateral side of the second second subcore 1.2. This means that a projection of the second first subcore 1.1 perpendicular to the longitudinal axis 7 onto the first second subcore 1.2 intersects it, and that a projection of the second first subcore 1.1 perpendicular to the longitudinal axis 7 onto the second second subcore 1.2 intersects it. Preferably, the lateral side of the second first subcore 1.1 overlaps the lateral side of the first second subcore 1.1 by at least a minimum overlap length.2 and at least the minimum overlap length of the lateral side of the second subcore 1.2. The minimum overlap length is at least one percent, preferably at least two percent, of the shortest subcore (in longitudinal direction 7) of the second subcore 1.1, the first subcore 1.2, and the second subcore 1.2, preferably of the shortest subcore (in longitudinal direction 7) of all subcores 1.1, 1.2. This forms a magnetic bridge at the contact point between the two second subcores 1.2 connected in series. The second subcores 1.2 are preferably arranged one behind the other in longitudinal direction 7. Preferably, the second subcores 1.2 are arranged one behind the other such that the longitudinal axes of the second subcores 1.2 are coaxial, i.e., the longitudinal axes of the second subcores 1.2 are the respective extensions of the adjacent second subcores 1.2.Preferably, the first axial side of the first second subcore 1.2 is arranged opposite the first axial side of the second second subcore 1.2. Preferably, the second subcores 1.2 are arranged one behind the other such that the first axial side of the first second subcore 1.2 completely overlaps the axial side of the second second subcore 1.2, i.e., the axial side of the first second subcore 1.2 overlaps the first axial side of the second second subcore 1.2 and / or the first axial side of the second second subcore 1.2 overlaps the first axial side of the first second subcore 1.2. In other words, a second subcore 1.2 represents a longitudinal extension 7 of the adjacent second subcore 1.2. In one embodiment, the second subcores 1.2 are arranged with a distance between their axial sides (see second embodiment).In one embodiment, the axial sides of the second sub-cores 1.2 are arranged in contact with each other (see first embodiment). The distance can be chosen to be arbitrarily large, as long as each first sub-core 1.1 extends over the opposite axial sides of two adjacent second sub-cores 1.2 and / or overlaps the adjacent second sub-cores 1.2 on their lateral sides.

[0021] The core 1 is thus formed by a plurality of subcores 1.1, 1.2 arranged one behind the other and next to each other. The core 1 has two opposite ends in the longitudinal direction 7, which are formed by the corresponding ends or axial sides of the respective last first or second subcores 1.1, 1.2 in the longitudinal direction 7.

[0022] The coil 2 is wound around the core 1, preferably around the core support 4. The winding direction of the coil 2 is longitudinal 7. The coil 2 preferably has a plurality of turns around the core 1, preferably more than two, more than five, more than ten, more than fifteen, and more than twenty turns. The coil 2 preferably extends from the first end of the core 1 to the second end of the core 1, such that the area between the last turn of the coil 2 towards the first end of the core 1 and the last turn of the coil 2 towards the second end of the core 1 comprises at least 70%, preferably at least 75%, and preferably at least 80% of the longitudinal extent of the core 1. Preferably, the coil 2 extends over both first sub-cores 1.1, and preferably over all first sub-cores 1.1. Preferably, the coil 2 isA coil wire of coil 2 is wound onto the core support 4. However, it is also possible for coil 2 or the coil wire (without a core support 4) to be wound directly onto the core 1. Coil 2 preferably has a coil wire that is wound around the core 1 or the core support 4. The coil wire is preferably insulated. Preferably, the coil wire is wound such that both ends of the coil wire are connected to antenna terminals at one end of the core 1. In the illustrated embodiment, 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 routed back from the second end of the core 1 to the first end of the core 1 (without any turns around the core 1).It would also be possible to first guide the coil wire from the first end of core 1 to the second end of core 1 (without winding around core 1) and then wind it from the second end of core 1 to the first end of core 1 in one direction. It is also possible to wind the coil wire in both directions (cross-winding).

[0023] The core support 4 is designed to carry / hold the core 1. This is particularly important for assembling the antenna before potting, ensuring that all antenna components are held in the correct position before the antenna is potted. The features of the core support 4 described below therefore refer to the state before the antenna is potted, unless explicitly stated otherwise. The core support 4 is preferably designed to carry the coil 2. Preferably, the core support 4 has an inner opening in which the core 1 is held. Preferably, the core support 4 has an outer surface on which the coil 2 is wound. The core support 4 preferably fixes (at least in one direction) the position of the sub-cores 1.1, 1.2 relative to each other. Preferably, the core support 4 fixes the sub-cores 1.1, 1.2 such that they are perpendicular to the longitudinal axis of the core 1 and the sub-cores 1.1, 1.2, respectively.2 (at least in one direction, preferably in all directions 330°, preferably 350° radially around the longitudinal axis, preferably in all directions radially around the longitudinal direction 7). Preferably, the coil 2 is wound onto the core carrier 4 or onto core 1 (without core carrier 4) such that the coil windings press the two second sub-cores 1.2 against the first sub-cores 1.1 and thus fix their position. According to the invention, the sub-cores 1.1, 1.2 are inserted for assembly in the direction of the longitudinal axis of the core 1 or the sub-cores 1.1, 1.2, respectively. This allows the sub-cores 1.1, 1.2 to be positioned stably relative to each other and yet still be able to move axially relative to each other. However, it is also possible to insert the sub-cores 1.1, 1.2 into the core carrier 4 differently, e.g., in the stacking direction. This possibility, however, is not within the scope of the claims.Preferably, the core support 4 extends over at least 70%, preferably at least 80%, and preferably at least 90% of the length of the core 1. This allows for stable support of the sub-cores 1.1, 1.2. This is advantageous for positioning during manufacturing and also stabilizes the encapsulated sub-cores 1.1, 1.2 later in application. In the illustrated embodiment, the core support 4 has at least one, preferably two, parallel longitudinal beams 41 (which extend in the direction of the longitudinal axis of the core 1). Preferably, the core support 4 has a plurality of transverse beams 42 that prevent / block the movement of the sub-cores 1.1, 1.2 radially to the longitudinal axis 7 of the core 1, particularly in the third direction 9. In the area of ​​the transverse beams 42, the winding of the coil 2 is preferably interrupted. Preferably, the transverse beams 42 each connect the two longitudinal beams 41.For the purpose of description, four sides (perpendicular to the longitudinal axis of the core 1) of the core 1 are designated as the upper side (or first side), the lower side (or second side), and two lateral sides (third and fourth sides), without thereby limiting the invention to a specific orientation of the antenna. Preferably, the upper and lower sides are opposite each other and / or the two lateral sides are opposite each other. There are preferably upper crossbeams 42 against which the upper side of the core 1 rests. There are preferably lower crossbeams 42 against which the lower side of the core 1 rests. Preferably, the two longitudinal beams 41 are arranged on the two lateral sides of the core 1, so that the two lateral sides of the core 1 rest against the two longitudinal beams.The core carrier 4 preferably has a closure area 43 at one end, which is designed to close an opening in the housing 3 when the core carrier 4 (with the core 1 and the coil 2) is mounted in the housing 3. The closure area 43 can be integrally manufactured as a single piece with the rest of the core carrier 4. However, it is also possible for the closure area 43 and the rest of the core carrier 4 to be assembled from separate parts (see first and second embodiments). The closure area 43 preferably has a connection for the electrical connection of the antenna, in particular the coil 2. Preferably, the connection has two electrically conductive rods that extend through the closure area 43. One end of each conductive rod protrudes from the closure area 43 on the outer side, so that the finished antenna can be electrically connected.The opposite side of each conductive rod protrudes on the inner side of the closure area 43, with the ends of the coil 2 and the coil wire, respectively, being connected to one of these conductive rods (on the inside). The core carrier 4 is preferably designed such that, after assembly in the housing 3, it has a predefined position. On one side of the antenna, this is achieved, for example, by positioning the closure area 43 in the opening of the housing 3. Preferably, the core carrier 4 further comprises positioning means that hold the core carrier 4 in the predefined position when the core carrier 4 is mounted in the housing 3. The further positioning means are preferably arranged on the area of ​​the core carrier 4 opposite the closure area 43.Preferably, the positioning means have flexible / spring-loaded arms that press against the inner wall of the housing 3, thus bringing the core carrier 4 into the predefined position within the housing 3. The spring action of the positioning means dampens the core 1, protecting it against impacts. The core carrier 4 is preferably made of a plastic.

[0024] The housing 3 is designed to enclose the core 1 with the coil 2. Preferably, the housing 3 is designed to enclose the core carrier 4 with the core 1 and the coil 2. The housing 3 preferably has an opening designed to allow the core 1 with the coil 2, or the core carrier 4 with the core 1 and coil 2, to be inserted into the housing 3. Preferably, the opening is closed by the core carrier 4 in the inserted state. However, it is also possible for the opening to be closed by a separate cover.

[0025] A potting compound 5 is arranged between the housing 3 and the core 1 with the coil 2, or the core carrier 4 with the core 1 and the coil 2. The core 1 with the coil 2, or the core carrier 4 with the core 1 and the coil 2, is inserted into the housing 3 and potted therein with the potting compound 5. The potting compound 5 is often also referred to as potting. The potting compound 5 preferably fills the, preferably all, cavities in the housing 3, so that the heat from the core 1 and the coil 2 is effectively dissipated and the core 1 with the coil 2, or the core carrier 4 with the core 1 and the coil 2, is stably mounted. Preferably, a potting compound 5 is used that (in the cured state) is softer than 60 Shore A, preferably softer than 40 Shore A, preferably softer than 35 Shore A, preferably softer than 30 Shore A, preferably softer than 27 Shore A, preferably softer than 25 Shore A.It was found that the potting compound 5, being softer than 60 Shore A or the other preferred values ​​mentioned, not only improves fracture resistance but also, surprisingly, improves the stability of the antenna's electrical properties. Preferably, however, the potting compound 5 (in its cured state) is harder than 10 Shore A, and more preferably than 15 Shore A. The potting compound 5 with a deformation between 10 and 35 Shore A was found to be particularly advantageous.

[0026] Preferably, the described antenna is designed for use in a vehicle for transmitting key data for opening and / or starting the vehicle. Preferably, this antenna is mounted in a vehicle.

[0027] To manufacture the antenna, the sub-cores 1.1 and 1.2 are first mounted in the core carrier 4 as previously described. The coil 2 is wound onto the core carrier 4. The coil wire is connected to the antenna terminal. The core 1 with the coil 2, or the core carrier 4 with the core 1 and the coil 2, is inserted into the housing 3. The core 1 with the coil 2, or the core carrier 4 with the core 1 and the coil 2, is then potted in the housing 3 with the potting compound 5. The potting compound 5 then hardens, and the antenna is complete.

Claims

1. Antenna comprising a magnetic core (1), a core carrier (4) and a coil (2) wound around the magnetic core (1), wherein the magnetic core (1) comprises at least two first sub-cores (1.1), the at least two first sub-cores (1.1) being arranged one behind the other in a longitudinal direction (8) of the magnetic core (1), each of the at least two first sub-cores (1.1) having a lateral side, the at least two first sub-cores (1.1) comprising a first first sub-core (1.1) and a second first sub-core (1.1); wherein the magnetic core (1) comprises at least one second sub-core (1.2), the at least one second sub-core (1.2) comprising a first second sub-core (1.2) which is arranged on the lateral side of the first first sub-core (1.1) and on the lateral side of the second first sub-core (1.1) such that the first second sub-core (1.2) overlaps at least partially with the first first sub-core (1.1) and at least partially with the second first sub-core (1.1), such that the first second sub-core (1.2) forms a magnetic bridge from the first first sub-core (1.1) to the second first sub-core (1.1), the at least two first sub-cores (1.1) and the at least one second sub-core (1.2) being held in the core carrier (4), and the coil (2) being wound around the core carrier (4); wherein the core carrier (4) and the coil (2) wound around the core carrier (4) are designed such that the winding of the coil (2) presses the at least one second sub-core (1.2) against the lateral sides of the at least two first sub-cores (1.1) and thereby fixes their position, characterized in that the core carrier (4) is configured to allow the first and second sub-cores (1.1, 1.2) to be inserted for assembly in the direction of the longitudinal axis of the sub-cores (1.1, 1.2).

2. Antenna according to claim 1, wherein the lateral side of the first first sub-core (1.1) forms a planar surface, wherein the lateral side of the second first sub-core (1.1) forms a planar surface, the first second sub-core (1.2) has a lateral side that forms a planar surface, the lateral side of the first second sub-core (1.2) rests on the lateral side of the first first sub-core (1.1) and on the lateral side of the second first sub-core (1.1).

3. Antenna according to claim 1 or 2, wherein the lateral side of the first first sub-core (1.1) is arranged parallel to the longitudinal direction (7) of the core, and / or the lateral side of the second first sub-core (1.1) is arranged parallel to the longitudinal direction (7) of the core, and / or the lateral side of the first second sub-core (1.2) is arranged parallel to the longitudinal direction (7) of the core.

4. Antenna according to any one of the preceding claims, wherein a longitudinal axis of the first first sub-core (1.1) and / or a longitudinal axis of the second first sub-core (1.1) is arranged parallel to a longitudinal axis of the first second sub-core (1.2).

5. Antenna according to any one of the preceding claims, wherein the first first sub-core (1.1) and the second first sub-core (1.1) are arranged one behind the other such that a longitudinal axis of the first first sub-core (1.1) forms an extension of a longitudinal axis of the second first sub-core (1.1).

6. Antenna according to any one of the preceding claims, wherein the at least two first sub-cores (1.1) are arranged in a first plane and the at least one second sub-core (1.2) is arranged in a second plane, the second plane preferably being parallel to the first plane.

7. Antenna according to any one of the preceding claims, wherein the first first sub-core (1.1) has a rectangular cross-section and / or the second first sub-core (1.1) has a rectangular cross-section, the first second sub-core (1.2) has a rectangular cross-section, wherein the magnetic core (1), in the region in which the first first sub-core (1.1) overlaps with the first second sub-core (1.2), again forms a rectangular cross-section, and / or the magnetic core (1), in the region in which the second first sub-core (1.1) overlaps with the first second sub-core (1.2), again forms a rectangular cross-section.

8. Antenna according to any one of the preceding claims, wherein the first first sub-core (1.1) has a rectangular cross-section and / or the second first sub-core (1.1) has a rectangular cross-section, the first second sub-core (1.2) has a rectangular cross-section, the magnetic core (1), in the region in which the first first sub-core (1.1) overlaps with the first second sub-core (1.2), again forms a rectangular cross-section, and / or the magnetic core (1), in the region in which the second first sub-core (1.1) overlaps with the first second sub-core (1.2), again forms a rectangular cross-section.

9. Antenna according to any one of the preceding claims, wherein the core carrier (4) extends over at least 80% of the length of the magnetic core (1), and / or the coil (2) is wound on the core carrier (4) such that the coil (2) extends over more than 80% of the length of the magnetic core (1).

10. Antenna according to any one of the preceding claims, comprising a housing (3) and a potting compound (5), wherein the magnetic core (1) with the coil (2) is arranged in the housing (3) and potted in the housing (3) with a potting compound (5), wherein the potting compound (5) is softer than 40 Shore A.

11. Method for manufacturing an antenna, comprising the steps of: • arranging a magnetic core (1) in a core carrier (4); • winding the core carrier (4) with the magnetic core (1) with a coil (2); wherein the magnetic core (1) comprises at least two first sub-cores (1.1), the step of arranging the magnetic core (1) comprises arranging the at least two first sub-cores (1.1) one behind the other in a longitudinal direction (8) of the magnetic core (1); the at least two first sub-cores (1.1) comprise a first first sub-core (1.1) and a second first sub-core (1.1); the magnetic core (1) comprises at least one second sub-core (1.2), wherein the at least one second sub-core (1.2) comprises a first second sub-core (1.2), arranging the magnetic core (1) comprises arranging the first second sub-core (1.2) such that it is positioned on the lateral side of the first first sub-core (1.1) and on the lateral side of the second first sub-core (1.1) so that it overlaps at least partially with the first first sub-core (1.1) and at least partially with the second first sub-core (1.1), thereby forming a magnetic bridge from the first first sub-core (1.1) to the second first sub-core (1.1); the core carrier (4) and the coil (2) wound around the core carrier (4) are designed such that the winding of the coil (2) presses the at least one second sub-core (1.2) against the lateral sides of the at least two first sub-cores (1.1) and thus fixes their position, characterized in that the first and second sub-cores (1.1, 1.2) are inserted for assembly in the direction of the longitudinal axis of the sub-cores (1.1, 1.2) into the core carrier (4) before the coil is wound onto the core carrier (4), or in that the core carrier (4) with the magnetic core (1) and the coil (2) is positioned in a housing and potted with a potting compound (5).

12. Vehicle comprising an antenna according to any of claims 1 to 10, or an antenna produced by the method according to claim 11, wherein the antenna is configured for the transmission of key data for unlocking and / or starting the vehicle.