DE202012012880U1 - coil system - Google Patents

Abstract

A coil system with at least two coupled coils - at least one carrier device (3) accommodating a layer structure, which carries conductor tracks on at least two layers and at least one RFID / NFC interface (4), - and an RFID / NFC device (10) at least one RFID / NFC device coil (8), which can assume different relative orientations with respect to the carrier device, - with layers comprising conductor tracks being separated from one another by at least one insulation layer and with at least one segment of a first conductor track and at least one segment of a second conductor track is arranged on a second layer and the at least one segment of the conductor track on the first layer is electrically conductively connected to the at least one segment of the conductor track on the second layer via contacts such that the conductor track segments that are electrically conductively connected to one another at least one W forming a first coil (50, 50a) which is connected as an antenna to the RFID / NFC interface (4) and whose central coil axis runs essentially parallel to the layers, in particular parallel to the layers.

Description

The present invention relates to a coil system which has at least one carrier structure accommodating a layer structure, which carries printed conductors on at least two layers and at least one RFID / NFC interface, and an RFID / NFC device having at least one coil, wherein the at least one RFID / NFC device coil with respect to the carrier device can assume different relative orientations.

In the field of wireless communication interfaces, systems based on inductive coupling offer the possibility of exchanging contactless information and / or energy at a range of typically a few centimeters between the subscribers. Examples of such communication interfaces based on inductive coupling may be RFID (Radio Frequency Identification) systems or systems based on NFC (Near Field Communication) technology. Inductive wireless systems have in common that each participant of the inductive energy and / or data interface needs at least one internal or external antenna, which is often designed as a coil shape. Such coil systems are the subject of the invention.

In the field of RFID technology (radio frequency identification) subscribers of the wireless communication interface typically consist of one or more RFID readers (also called readers or read / write devices) that build a magnetic field and within reach RFID transponder (tags or RFID Called chips) read, describe and / or can provide energy.

In the field of Near Field Communication (NFC) technology, NFC subscribers can take on different roles; for example, they can exchange data as more or less equal partners via the inductive interface, or an NFC subscriber can assume the role of a reader and thus, for example, compatible ones Read RFID transponder. Alternatively or additionally, an NFC subscriber can also play the role of an RFID transponder, which provides a partial compatibility between the different technologies.

Inductive energy and information channels are not limited to RFID or NFC technology. Thus, other frequencies can be used or the information transfer is realized in a proprietary way. In the following, including the claims, the term RFID / NFC is used to represent inductive energy and / or communication interfaces, but other inductive energy and / or information transmission techniques are explicitly included.

Thus, hereinafter including the claims, an RFID / NFC interface refers to an electronic device that provides an interface for the inductive transmission channel. This can be z. B. an RFID transponder, which consists for example of a single IC (Integrated Circuit). The possibly connected antenna or coil is not included in this context. Alternatively, an RFID / NFC interface may also include various electronic components, such as an amplifier, matching network, one or more resonant capacitors, or a lead to an external antenna.

An RFID / NFC device in the following, including the claims, an electronic module that contains electronics, an RFID / NFC interface, at least one antenna or coil and optionally contains one or more antenna feed line. An example of an RFID / NFC device is an RFID reader.

In the field of RFID / NFC technology are often RFID / NFC interfaces on a support device z. B. integrated on a printed circuit board, so that it can be linked to the carrier device in the form of a barcode replacement unique information or a wireless communication interface with a on the support means, in particular in the manner of a circuit board or a circuit board-like structure, applied electronics can be constructed to B. to configure the electronics or read out evaluation data.

For the wireless communication between an RFID / NFC device and the electronics arranged on the carrier device by means of the RFID or NFC interface, the RFID / NFC interface usually requires an antenna connected to it. When combined with a printed circuit board, in some cases it may be convenient to run the antenna directly as a printed or etched circuit board antenna. The design of the antenna by printed conductors on the circuit board has the decisive advantage that virtually no additional costs and additional production steps arise, also good reproducibility can be ensured.

For inductive applications from the kHz range to the MHz range, the antennas are often designed as coils. As examples, helical coils wound or etched around a ferrite body can serve. Frequently also air coils become without magnetic core, but magnetic cores may also be used to concentrate the magnetic energy or to shield the magnetic fields from interfering objects such as metals.

A system for the contactless exchange of energy and data based on RFID technology is z. In DE 697 29 865 T2 described. The WO 2010/123926 discloses a method for producing a spiral RFID coil to which a capacity and an RFID tag can be connected, if necessary. In US 5,727,408 A For example, a circuit board of magnetically active material is surrounded by a tortuous coil, the application of which is not in the RFID / NFC range. In US 2007/0012771 A1 is described an RFID bracelet with associated antenna form, the coil is integrated in a special form in the bracelet. In EP 1 561 129 B1 an RFID tag is described with a special coil shape, the windings of the coil partially have a different sense of winding. In EP 1 652 132 B1 an RFID unit is described in which at least parts of the antenna can be changed when events occur. In EP 1 646 122 A1 An electronic device is described with a printed circuit board and a coil located thereon, which is formed of conductor tracks. In US 4,866,573 A a wound coil is described which can be mounted on a printed circuit board. In DE 103 34 830 A1 describes a printed circuit board coil with integrated magnetic core for the LF (Low Frequency) range, ie at low frequencies of approximately 100 to 135 KHz. The EP 2 341 463 A2 and EP 1 843 281 A1 show data carrier / transmitter devices in which the coil axes extend parallel to the plane of the data carrier. The WO 2011/091830 A1 shows a portable data carrier with radio-based data communication device. The coil axis can run parallel to the plane of the data carrier and perpendicular to the coil axis ferrite layers are provided on both sides of the coil. The DE 10 2010 042 395 A1 shows a method and systems for inductively charging batteries of a vehicle, wherein an automatic placement of the coils involved is provided in order to make the energy transfer during charging as efficient as possible.

Coupled coil systems such as may occur in RFID / NFC systems typically include location and orientation dependent magnetic coupling. It may happen that a system behavior that works well in parallel and coaxial alignment of both coils can no longer be maintained if, for example, a coil is rotated 90 degrees in a certain direction. In this case, magnetic fields can be perpendicular to each other and very little magnetic coupling between the coils can occur. For example, when the rotated coil is laterally displaced, system functionality can be restored.

An object of the invention is to provide an improved coil system for coupled coils for inductive RFID / NFC applications with mounted on a support means antennas or coils, which in particular also in juxtaposed carrier devices which z. B. modules lined up on a mounting rail modules without gaps form with RFID / NFC coils formed thereon, can be effectively read out with conventional coils of an RFID / NFC device, configured and / or can be supplied with energy.

The inventive solution of the problem is given by a coil system according to claim 1. Advantageous embodiments and further developments are the subject of the dependent claims.

The invention therefore proposes a coil system with at least two coupled coils, which carries at least one carrier structure accommodating a layer structure, which carries printed conductors on at least two layers and at least one RFID / NFC interface, and an RFID / NFC device with at least one RFID / NFC device coil which can assume different relative orientations with respect to the carrier device. For this purpose, layers comprising interconnects are separated from one another by at least one insulation layer, wherein at least one segment of a first interconnect is arranged on a first layer and at least one segment of a second interconnect on a second layer, and wherein the at least one segment of the interconnect on the first layer is connected to the first layer at least one segment of the conductor track on the second layer is electrically conductively connected to one another via contacts such that the conductor track segments connected to one another in an electrically conductive manner form at least one turn of a first coil. This coil is connected as an antenna to the RFID / NFC interface and has a central coil axis, which runs substantially parallel to the layers, in particular parallel to the layers.

Consequently, a better inductive coupling can be established between the RFID / NFC device coil and the first coil in alignment with the coil axis of the RFID / NFC device coil in parallel, but at least substantially parallel, to the layers of the carrier device.

An advantage of the invention is therefore based on the fact that the magnetic coupling for certain geometric orientations of the coils can be optimized or maximized. This is the case in particular for geometrical orientations or orientations of the coupled coils relative to one another in the case where conventional systems can fail or do not achieve optimal results. This is especially the case when thin juxtaposed devices, eg. B. attached to a mounting rail modules without gaps, to be equipped with RFID / NFC interfaces and associated coils and to be read out, configured or supplied with conventional RFID / NFC device coils.

The invention thus uses geometrical optimizations of the coil on the support means, e.g. B. board or circuit board. The central coil axis or at least a part thereof is chosen contrary to conventional solutions so that it is parallel or nearly parallel to the base surface of the support means, on which base the coil is arranged. By this measure, a significant coupling for such coil arrangements can be created, in which a coupling could otherwise be very low.

In order to form such a coil arranged on the carrier device, in particular a helical or cylindrical basic shape has proven to be expedient.

If a printed circuit board is used as the carrier device, the first coil formed on the carrier device can be constructed inexpensively and with standard components, since as a rule an available area on the printed circuit board can be used for the coil, and printed conductors of the printed circuit board itself form the first coil are usable. Consequently, the first coil causes almost no additional costs, and other electronic components can be accommodated on the same circuit board as the first coil.

The coil system according to the invention is particularly suitable for embodiments in which the RFID / NFC device coil, which can be aligned in different orientations to the carrier device, is designed as a spiral flat coil. Because in conventional coils, the spiral z. B. are housed on a circuit board, in certain orientations of the coils to each other, the coupling can be very low and a system functionality may not be guaranteed. On the other hand, in order to improve the functionality for these arrangements, the coil form of the RFID / NFC circuit board coil according to the invention is designed such that the alignment of both coils, ie the first coil formed on the carrier device and the RFID / NFC device coil, is selected to one another is that magnetic field lines can pierce the other coil surface and thus can contribute to a significant coupling of the two coils, so that a system functionality may continue to exist.

Preference is therefore given to a coil system in which the proportion of a magnetic field between the RFID / NFC device coil and the first coil can be used, in which the field lines extend parallel to the layers of the carrier device.

To improve the coupling properties to the RFID / NFC device coil and / or to increase the inductance of the coil system, a magnetic core, in particular a ferrite core, may be integrated within the first coil.

The coil system according to the invention expediently further comprises a composite coil, such that the first coil forms only a coil portion of the composite coil, which is connected as an antenna to the RFID / NFC interface, wherein the composite coil both the coil portion of the first coil and at least one has second coil portion formed on the support means, which connected to the coil portion of the first coil electrically connected in series or parallel and the central coil axis substantially perpendicular to the layers, in particular perpendicular to the layers of the support means, the at least one second coil portion contribute to the functionality, when the coil axis of the RFID / NFC device coil of a Alignment parallel, but at least substantially parallel to the layers of the carrier device towards an orientation in the direction perpendicular, but at least substantially perpendicular to the layers of the carrier device changes.

The coil system according to the invention in this alternative or complementary embodiment expediently further comprises a composite coil, such that the first coil forms only a coil portion of the composite coil, which is connected as an antenna to the RFID / NFC interface, wherein the composite coil both the coil portion the first coil and at least one third formed on the support means coil portion which connected to the coil portion of the first coil electrically connected in series and / or parallel and its central coil axis substantially parallel to the layers, in particular parallel to the layers of the support means, but in With respect to the coil axis of the coil portion of the first coil is rotated about the normal of the layers of the carrier device, the at least one third coil portion may contribute to the functionality when the coil axis of the RFID / NFC device coil from an orientation parallel, i However, it is substantially parallel to the layers of the support means to an alternative orientation in the direction parallel, but at least substantially parallel to the layers of the support means, and to rotate about the normal of the layers of the support means.

Further advantages and features of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. In the drawings show:

1 an embodiment of the invention with an optimized circuit board coil,

2 Another embodiment of the invention with an optimized PCB coil,

3 Another embodiment of the invention with an optimized PCB coil,

4 Another embodiment of the invention with an optimized PCB coil,

5 schematically the composite inductances and couplings of the circuit board coil according to the invention 4 .

6 a further embodiment of the invention with coils of different orientations,

7 the coupling process of the embodiment 6 for different orientations of the coils,

8th an embodiment of a conventional RFID / NFC coil system according to the prior art with favorable orientation of the coils to each other, and

9 an embodiment of the conventional RFID / NFC coil system according to 8th in unfavorable orientation of the coils to each other.

For a better understanding of the invention is first on the 8th and 9 which show an embodiment of a conventional RFID / NFC coil system according to the prior art.

8th shows very simplified and only in parts, an electronic device module 2 , which can be used for industrial applications, for example. The electronic device module 2 can equally be located in other areas such as consumer electronics. The device module 2 Can be either portable or, as at 8th to see on a bracket 1 be attached, which may be formed in a industrial environment, for example, from a mounting rail. Within the device module 2 there is at least one carrier device 3 with layer or layer structure, z. As a circuit board, which is also referred to as a circuit board, board or PCB (Printed Circuit Board). Printed circuit boards typically consist of a layer or layer structure with at least two electrically conductive layers or layers, which are spatially and electrically separated from one another by at least one insulating layer or layer. The layer or layer structure of the circuit board may also consist of a plurality of different layers or layers. It should be noted, however, that instead of a printed circuit board other three-dimensional structures can be used as a carrier device with a suitable layer structure.

The carrier device 3 with layer or layer structure is with an RFID / NFC interface 4 , z. B. in the manner of a radio chip, based on the RFID / NFC technology or a similar technology. The RFID / NFC interface can, for. B. be designed passive (power supply via the magnetic alternating field), or active with external power supply. Furthermore, an external contact-type data interface to external electronic components (not shown) may be present.

In such a case, it is often useful to the RFID / NFC interface 4 associated antenna or coil 5 directly on the carrier device 3 train. Used as a carrier device 3 a printed circuit board, this has the advantage that the coil 5 can be constructed as a circuit board coil of conductors without significant additional costs, since no additional production step is required. In addition, can be dispensed with an external antenna or coil. Often, such, directly on the carrier device 3 trained coils 5 , And thus in particular PCB coils, formed in a spiral shape with at least one turn. When multiple windings are required, the spiral windings are often mounted on one layer or layer and the innermost or outermost winding of the spiral shape is returned to another layer or layer of the layer structure. The layers comprising the turns are consequently separated from one another by at least one insulating layer. This approach avoids, inter alia, short circuits between the turns of the coil. The spiral basic structure of the coil 5 is often circular, but also other shaped structures such as rectangular basic shapes are often used with rounded corners.

In the design of the coil form, it is particularly advantageous, the shape of the coil and the number of turns electrically to the RFID / NFC interface 4 which can lead to a particularly optimal system functionality. Under certain circumstances, it may also be useful to attach an electrical matching network, in the simplest case a capacitor connected in series or parallel to the antenna in order to be able to optimally exploit resonant effects.

Will be another RFID / NFC interface 6 (eg an RFID transceiver within an RFID reader) as a counterpart to the RFID / NFC interface 4 near the device module 2 brought and the RFID / NFC interface 6 with another, to the RFID / NFC interface 6 belonging antenna or coil 8th and possibly a supply line 7 Equipped with a magnetic coupling between the RFID / NFC interface 4 belonging antenna or coil 5 and the to the RFID / NFC interface 6 belonging antenna or coil 8th arise and it can be between the RFID / NFC participants, ie between the RFID / NFC interface 4 and the RFID / NFC interface 6 , Energy and / or data are exchanged. Once in the RFID / NFC interface 6 belonging coil 8th a current flows, forms a magnetic field, which at 8th with two field lines 9 is shown symbolically. If this magnetic field is variable in time, the field passing through the coil surface can pass through to the RFID / NFC interface 4 belonging coil 5 a voltage can be induced, which in turn is used to power the RFID / NFC interface 4 can be used. A targeted temporal change of the induced voltage can also be used to transfer information between the coils 8th and 5 be used. The same applies accordingly also for the opposite direction.

If both central axes of the coils 5 and 8th parallel or nearly parallel to each other and both coils are arranged more or less coaxially, a good magnetic coupling between the coils can 5 and 8th set and a system functionality can be given. This relative alignment of the two coils is thus a preferred application in the prior art.

In 9 is the RFID / NFC interface 6 together with the supply line 7 and the antenna 8th to an RFID / NFC device 10 summarized. Opposite the arrangement 8th is the RFID / NFC device 10 rotated so that the coil axis of the RFID / NFC interface 6 belonging coil 8th now more or less parallel to the layers of the carrier device 3 used circuit board and substantially perpendicular to the layer or PCB normal N (see. 1 ) and thus also substantially perpendicular to the coil axis of the RFID / NFC interface 4 belonging coil 5 stands. In this case, any field lines 9 the current-carrying coil 8th the coil surface of the coil 5 barely or in the worst case no longer flood and it can only be a very small or minimal coupling between the coils set. In this case, consequently, a system functionality may be compromised or the communication between the RFID / NFC subscribers may fail. This scenario forms the starting point for the invention, since such an arrangement between the RFID / NFC interface 6 belonging antenna 8th and the electronic device module 2 may occur in some applications and should be given to each other in such orientations of the components correct functionality.

In 1 is a first arrangement according to the invention with a modified coil geometry for an arrangement between an RFID / NFC device 10 with associated RFID / NFC interface 6 , optional supply 7 and antenna 8th and a device module 2 as in 9 outlined. An inventive, the RFID / NFC interface 4 belonging and connected to this first coil 50 out 1 replaces the coil 5 of the prior art according to 8th and 9 and is designed such that for a rotated RFID / NFC interface 6 with associated supply line 7 and coil 8th whose coil axis is parallel, but at least substantially parallel to the layers of the carrier means, a significant magnetic coupling between the coils 50 and 8th can be achieved.

This is made possible by the fact that the central coil axis of the coil 50 now also parallel to the layers of the carrier device 3 , according to 1 So parallel to the carrier device 3 used circuit board, and thus also runs parallel or at least almost parallel to the coil axis of the RFID / NFC interface 6 belonging coil 8th lies. Thus, both winding axes are aligned more or less parallel to each other and the field lines 9 an alternating magnetic field of the coil 8th may be the coil area of the newly formed first coil 50 flood. Thus, both coils can be sufficiently coupled together and an energy and / or data transmission between the RFID / NFC participants can with rotated RFID / NFC interface 6 be enabled.

In 2 a further embodiment of the invention is shown. The essential properties are identical to 1 , where in 2 however, more detailed on a preferred for the invention geometric structure of the first coil 50 has been received. In the 2 directly on the carrier device 3 trained coil 50 , and thus in particular printed circuit board coil, is by means of contacting, in particular through-hole contacting (also referred to as plated-through holes or vias) 60a . 60b . 60c and 61a . 61b . 61c constructed, wherein the Durchlochkontaktierungen parts of the first coil 50 form, as z. B. from the DE 103 34 830 A1 is known. The number of vias is typically 2 x Nw, where Nw is the number of turns of the coil. The vias are on at least two conductive layers or layers of the layer or layer structure with each other via conductive segments or connecting elements 70a . 70b . 70c respectively. 71a . 71b . 71c connected with each other. These connecting elements are preferably constructed of sections of straight segments of printed conductors, but it can also be used rounded or partially curved conductor segments.

For example, the vias 60a and 61a on a lower layer with the connecting element 71a connected and the vias 61a and 60b on an upper layer with the connecting element 70b etc. Otherwise, those are the traces or fasteners 70a . 70b . 70c respectively. 71a . 71b . 71c comprehensive layers separated by at least one insulation layer. In this way, a helical or helical basic structure of the first coil results 50 with sections consisting of connecting elements, in particular segments of printed circuit traces of a printed circuit board, and of contacting elements.

Unlike conventional coils 5 to 8th and 9 Thus, the coil base is thus effectively shifted from the base of the carrier device with layer structure on the cross-sectional area of the carrier device with layer structure and the coil axis is aligned from originally perpendicular or nearly perpendicular to the base surface of the carrier device with layer structure aligned now parallel or nearly parallel to the base of the carrier device with layer structure turned.

Although the procedure according to the invention thus requires that the cross-sectional area of the coil base area and thus also the inductance of the coil is typically lower than in the conventional case. However, this effect can be at least partially compensated by a plurality of turns. A further improvement can also be achieved, for example, by using a magnetic body 51 , z. B. a ferrite body is integrated with a high permeability in the layer or layer structure of the support means, which in addition to the inductance increase also to an improvement of the coupling between the coils 50 and 8th can lead.

In the 1 and 2 described embodiment of the invention with the coil shape 50 Its flat design allows significant magnetic coupling to the RFID / NFC device coil 8th even in the event that multiple carrier devices with layered structure or flat device modules 2 Total next to each other on the bracket 1 , ie according to 1 one above the other, are strung together. This is possible because the portion of the magnetic field is used for coupling, that of the coil axis of the coil 50 and thus emerges from the cross-sectional area of the support means. In that sense, it is more or less irrelevant, whether next to the coil 50 , ie according to 1 over the coil 50 , even more equal or similar shaped coils of neighboring modules are located. Likewise, in this case, magnetic coupling between possible neighboring elements is minimized, which may be a desired positive effect.

In 3 is a further embodiment of the invention compared to the 2 slightly modified first coil 50 shown as a possible alternative.

In the 3 on the carrier device 3 trained coil 50 , And thus in particular PCB coil, in turn, by means of contacts 60a . 60b and 61a . 61b . 61c constructed, the parts of the first coil 50 form. Also, the contacts or vias are on at least two layers or layers of a layer or layer structure with each other via conductive segments or connecting elements 70a . 70b respectively. 71a . 71b . 71c connected with each other.

In modification to 2 is in place of the integrated ferrite body in the 3 as an element 52 a ferrite body, an additional circuit board or a combination thereof mounted on the support means 3 from this houses.

Also the carrier device 3 according to 3 with one or more mounted elements 52 can accommodate a layer structure within the scope of the invention and carry printed conductors on at least two layers.

Based on terminology as described in 2 are z. B. according to 3 the contacts or vias 61a and 60a as well as the contacts or vias 61b and 60b on a lower layer of the carrier device 3 even with the connecting element 71a respectively. 71b connected and the contacts or vias 60a and 61b as well as the contacts or vias 60b and 61c on an upper layer of the carrier device 3 worn element 52 with the connecting element 70a respectively. 70b connected.

Depending on the size of the item 52 can do this the contacts 60a . 60b and 61a . 61b . 61c through the element 52 be extended therethrough, according to the training 3 is this z. B. in the contacts 60a . 60b and 61b . 61c , Alternatively, after training 3 also on the upper layer of the element 52 extending conductive segments or fasteners 70a and 70b on the sides of the element towards the support means 3 be extended.

Furthermore, according to the training 3 the conductive connections from the contact 61a to the RFID / NFC interface 4 on an upper layer of the carrier device 3 yourself and from the contact 61c to the RFID / NFC interface 4 on a lower layer of the carrier device 3 even.

In other possible alternatives to this z. B. also the conductive connection of the contact 61c to the RFID / NFC interface 4 on an upper layer of the carrier device 3 itself or a lower layer of the carrier device 3 worn element 52 lie and / or the conductive segments or connecting elements 71a and 71b could be on a middle or upper layer of the carrier device 3 lie.

Obviously, further modifications are possible within the scope of the invention.

Accordingly, in the context of the following description, which in reference to, inter alia, coil training according to 1 and 2 In a modified way, coil formations are also based on the description 3 be used.

In 4 is a further inventive arrangement of a coil system with a modified coil geometry for the same arrangement between RFID / NFC device coil 8th and device module 2 as in 1 and 2 outlined. The on the carrier device 3 educated, turn with 50 marked coil off 4 replaces the coil 5 of the prior art and is designed such that even for a differently rotated RFID / NFC device 10 (includes 6 . 7 . 8th ) a significant magnetic coupling between the coils can be achieved. As a carrier device 3 in turn functioned appropriately a circuit board, so that at 4 shown coil 50 may be referred to below as a printed circuit board coil.

The sink 50 to 4 is however in modification to the first coil 50 to 1 and 2 from several parts of the coil 50a . 50b . 50c . 50d assembled, which are electrically connected to each other, so not just a first coil 50 to 1 and 2 but the composite coil 50 to 4 in total as an antenna to the RFID / NFC interface 4 connected.

The coil portion 50a corresponds to the first coil 50 to 1 and 2 and is therefore made of vias 60a . 60b . 60c and 61a . 61b . 61c constructed, wherein the plated-through holes parts of the coil portion 50a form. Again, the number of vias is typically 2 × Nw, where Nw is the number of turns of the coil portion 50a designated. The vias are on at least two conductive layers or layers of the printed circuit board assembly via conductive interconnecting elements 70a . 70b . 70c respectively. 71a . 71b . 71c connected with each other. These connecting elements are in turn preferably constructed of sections of straight segments of printed conductors, wherein also rounded or partially curved conductor segments can be used. Thus, according to the embodiment according to 1 and 2 for example the vias 60a and 61a on a lower layer with the connecting element 71a connected and the vias 61a and 60b on an upper layer with the connecting element 70b etc., so that preferably again a cylindrical spiral or helical basic structure of the coil portion 50a with respective sections consisting of tracks and vias results.

The special shape of the coil portion 50a conditionally as in the case of the first coil 50 to 1 and 2 in that its coil base area and thus also the inductance of this coil portion is typically lower than in the conventional case, but this effect is in turn at least partially due to a plurality of turns and / or by integration of a ferrite body 51a can be compensated in the layer structure, the latter in addition to the inductance increase also to an improvement of the coupling between the coils 50a and 8th can lead.

This special form of coil part 50a allows in turn that the central coil axis of the coil portion 50a now parallel to the layers of the carrier device 3 runs and thus also almost parallel to the coil axis of the according 4 aligned RFID / NFC device coil 8th lies. Thus, both coil axes are in the special alignment case 4 aligned more or less parallel to each other and the field lines 9 an alternating magnetic field of the coil 8th can the coil area of the coil portion 50a flood. Thus, the coil can 8th and the coil portion 50a be sufficiently coupled together and an energy and / or data transmission between the participants can be made possible.

At least a second coil part 50d is similar to the prior art, a spiral portion, at 4 outlined with rectangular basic structure and two turns. This coil portion 50d contributes to the functionality for such orientations, as in the prior art 8th occurrence. The coil base of the coil 50d thus remains on the base of the carrier device with layer structure, at which base the coil is arranged, and thus preferably on the circuit board base surface, wherein the coil axis of the coil portion 50d is further aligned perpendicular, at least substantially perpendicular to the base surface of the support means.

The other third coil components 50b and 50c are alternative or complementary to the second coil part 50d and similar to the coil portion 50a constructed, however, may have other numbers of turns or other trace shapes.

Also with the coil parts 50b and 50c Optionally ferrite bodies can be attached as it is, for example 51b is indicated. The individual coil components 50b . 50c However, they differ from the coil component 50a essentially in that they respectively in different directions of the support means 3 are oriented. The coil components 50b . 50c can contribute to system functionality in such cases when the RFID / NFC device coil 8th opposite to the 4 shown position on different pages next to the device module 2 placed and thus essentially around the normal N (vg. 1 ) of the layers of the carrier device is rotated around.

The composite coil according to the invention 50 according to the embodiment according to 4 is therefore made up of several coil components 50a . 50d or multiple coil components 50a such as 50b and or 50c or multiple coil components 50a . 50d such as 50b and or 50c wherein each coil portion respectively for different orientations and orientations of the RFID / NFC device coil 8th has different coupling contributions and thus all coil components together with optimized dimensioning can cover large angular ranges in which a system functionality can be guaranteed.

In 5 this relationship is shown in a sketchy equivalent circuit diagram. The RFID / NFC interface provided as RFID / NFC chip 4 is to the coil 50 connected as described below 4 preferably of several coil parts 50a . 50b . 50c . 50d is composed, in turn 5 are represented by the inductors L50a, L50b, L50c, L50d. The coil components are in this case connected in series, which is represented by the connected lines between the individual inductors. Alternatively, a parallel or a serial / parallel connection of the coils can be considered. The coil components 50a . 50b . 50c . 50d can be magnetically coupled together. This is through an exemplary connection 81 outlines the mutual inductance between the coil 50a and 50b symbolizes.

The composite coil 50 is magnetic with the RFID / NFC device coil 8th coupled, which is represented by the inductance L8. To the RFID / NFC device coil 8th are the optional supply line 7 and the RFID / NFC interface 6 connected, so that these parts to the RFID / NFC device 10 combine. Depending on the spatial orientation of the coils 50 and 8th to each other there are different Teilgegeninduktivitäten or partial couplings between the RFID / NFC device coil 8th and the individual sub-coils 50a . 50b . 50c . 50d , An innovation according to the invention in this embodiment is thus that the individual spatially dependent mutual inductances or couplings sketched by the compounds 80a . 80b . 80c . 80d are designed such that the total mutual inductance or total coupling between the coil 50 and 8th independent or almost independent of the spatial orientation of the coils 50 and 8th within certain limits. This applies to a large number of spatial positions; however, due to this innovation according to the invention, for example, it can not be physically prevented that the overall coupling increases with increasing distance between the coils 8th and 50 becomes smaller and eventually falls below a critical coupling.

The facts described in the 4 illustrated inventive and largely position-independent coupling can be made from the example 6 be clarified. In this embodiment, a composite coil 50 again on a carrier device 3 used PCB with an RFID / NFC interface 4 electrically connected. The composite coil 50 to 6 consists of two coil parts, the two parts 50a and 50d according to 4 which are in turn connected in series. In a first case, the RFID / NFC device coil 8th as in 6 (a) sketched, arranged perpendicular to the circuit board. This corresponds to an angle of a = 0 °, the coil axis of the RFID / NFC device coil 8th thus runs parallel to the layers of the carrier device 3 , In this case, the coupling is 80d (see. 5 ) between the coil 8th and the coil portion 50d small and the coupling 80a (see. 5 ) between the coil 8th and the coil portion 50a greater. In simple terms, the total coupling can be interpreted as a kind of summation of both couplings. In the second case according to 6 (b) the RFID / NFC device coil is rotated a = 45 ° with respect to the layers of the carrier device 3 turned. The coupling 80a (see. 5 ) to the coil portion 50a thus decreases compared to the first case, but the coupling increases 80d (see. 5 ) to the coil portion 50d corresponding. The total coupling between coil 50 and coil 8th remains unchanged compared to the first case. In the third case in 6 (c) the angle of rotation has been increased to a = 90 ° and the coil axis of the RFID / NFC device coil 8th is perpendicular to the layers of the carrier device 3 , Compared to the first case after 6 (a) thus arise opposite conditions, inasmuch as that the coupling 80a to the coil portion 50a is low and the coupling 80d to the coil portion 50d higher fails. Overall, however, the total coupling remains at a similar constant level as in the first two cases. Forms in modification for the composite coil 50 to 6 at least a third coil portion, z. B. the coil portion 50c to 4 in addition or as an alternative to the second coil part 50d together with the coil portion 50a a composite coil 50 , so the coupling is reduced 80a to the coil portion 50a and the coupling increases 80c to the coil portion 50c when the RFID / NFC device coil 8th opposite to the 4 shown rotated substantially counterclockwise around the normal N of the layers of the carrier device and thus on one side next to the carrier device 3 or the device module 2 is placed.

As a result of the geometrical optimizations of the coil shape according to the invention, it is thus possible to achieve a relatively homogeneous magnetic coupling between the RFID / NFC device coil 8th and the RFID / NFC coil according to the invention 50 can be achieved for different spatial orientations of the coils. 7 clarifies this relationship for the embodiments 6 , where the concrete numerical values can be determined simulatively, for example. It can be seen that for any rotational angle a between zero and 90 degrees, the total coupling z. B. is in a range between 1.8% and 2.1%. This is a relatively homogeneous coupling over the entire angle of rotation, which can be sufficient to ensure permanent functionality between the RFID / NFC subscribers.

In summary, the in 4 to 7 described coil form according to the invention 50 due to its flat construction a significant magnetic coupling to the RFID / NFC device coil 8th for different orientations of the coils to each other. The magnetic coupling of the coils 8th and 50 is thus independent or nearly independent of the relative orientation of the coils to each other within specified limits. A system functionality can thus for example be given equally for both cases that the RFID / NFC device 10 as in 8th or as in 9 shown in front of the carrier device 3 or the electronic device module 2 but also in the event that the RFID / NFC device 10 from a position in front of the carrier device 3 or the electronic device module 2 towards a position on a side next to the support means 3 or the device module 2 is placed. Thus, the robustness compared to conventional coil shapes can be additionally increased and given a system functionality for a variety of applications.

LIST OF REFERENCE NUMBERS

1

bracket

2

electronic device module,

3

Carrier device,

4

RFID / NFC interface (eg RFID transponder),

5

Kitchen sink,

6

RFID / NFC interface (eg RFID transceiver),

7

supply,

8th

RFID / NFC device coil,

9

Field lines,

10

RFID / NFC device (eg RFID reader),

50

first coil

60a, 60b, 60c, 61a, 61b, 61c

vias

70a, 70b, 70c, 71a, 71b, 71c

conductive segments,

51, 51a

magnetic body, z. B. ferrite bodies,

52

Ferrite body or additional circuit board or combination

50a, 50b, 50c, 50d

Coil parts,

80a, 80b, 80c, 80d

Coupling / mutual inductance,

81

Coupling / mutual inductance,

a

Angle of the coil axis of the RFID / NFC device coil 8th .

N

normal,

Nw

Number of turns

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69729865 T2 [0011]
• WO 2010/123926 [0011]
• US 5727408 A [0011]
• US 2007/0012771 A1 [0011]
• EP 1561129 B1 [0011]
• EP 1652132 B1 [0011]
• EP 1646122 A1 [0011]
• US 4866573A [0011]
• DE 10334830 A1 [0011, 0046]
• EP 2341463 A2 [0011]
• EP 1843281 A1 [0011]
• WO 2011/091830 A1 [0011]
• DE 102010042395 A1 [0011]

Claims (9)

Coil system with at least two coupled coils comprising - at least one, a layer structure harboring support means ( 3 ), which interconnects on at least two layers and at least one RFID / NFC interface ( 4 ), and an RFID / NFC device ( 10 ) with at least one RFID / NFC device coil ( 8th ), which can assume different relative orientations with respect to the carrier device, wherein layers comprising interconnects are separated from one another by at least one insulating layer and wherein at least one segment of a first interconnect is arranged on a first layer and at least one segment of a second interconnect on a second layer and the at least one segment of the conductor track on the first layer is electrically conductively connected to the at least one segment of the conductor track on the second layer via contacts such that the conductor track segments connected to one another in an electrically conductive manner at least one turn of a first coil ( 50 . 50a ), which as an antenna to the RFID / NFC interface ( 4 ) is connected and whose central coil axis substantially parallel to the layers, in particular runs parallel to the layers. Coil system according to claim 1, wherein the first coil ( 50 . 50a ) has a helical or cylindrical spiral shape. Coil system according to claim 1 or 2, wherein the carrier device ( 3 ) is a printed circuit board. Coil system according to claim 1, 2 or 3, wherein the RFID / NFC device coil ( 8th ) is designed as a spiral flat coil. Coil system according to one of the preceding claims, wherein the proportion of a magnetic field between the RFID / NFC device coil ( 8th ) and the first coil ( 50 . 50a ) is usable, in which the field lines are parallel to the layers of the support means. Coil system according to one of the preceding claims, wherein in the first coil ( 50 . 50a ) a ferrite core ( 51 . 51a ) is integrated to increase the coupling / inductance. Coil system according to one of the preceding claims, wherein the first coil ( 50a ) forms only a coil portion of a composite coil, which as an antenna to the RFID / NFC interface ( 4 ), wherein the composite coil in addition to the coil portion of the first coil ( 50a ) at least one electrically connected to this second coil portion ( 50d ) whose central coil axis substantially perpendicular to the layers, in particular perpendicular to the layers of the carrier device ( 3 ) runs. Coil system according to one of the preceding claims, wherein the first coil ( 50a ) forms only a coil portion of a composite coil, which as an antenna to the RFID / NFC interface ( 4 ), wherein the composite coil in addition to the coil portion of the first coil ( 50a ) at least one electrically connected to this third coil portion ( 50b . 50c ) whose central coil axis substantially parallel to the layers, in particular parallel to the layers of the carrier device ( 3 ), but with respect to the coil axis of the coil portion of the first coil (FIG. 50a ) about the normal N of the layers of the carrier device ( 3 ) is twisted. Use of a coil system with at least two magnetically coupled coils for an electronic device module ( 2 ) mounted on a bracket ( 1 ) is mounted next to other electronic device modules, wherein the coil system comprises - at least one, a layer structure harboring carrier device ( 3 ), which interconnects on at least two layers and at least one RFID / NFC interface ( 4 ), and an RFID / NFC device ( 10 ) with at least one RFID / NFC device coil ( 8th ), which in relation to the carrier device ( 3 ) can assume different relative orientations, wherein conductor tracks comprise layers of the carrier device ( 3 ) are separated from each other by at least one insulating layer and wherein on a first layer at least one segment ( 70a - 70c ) of a first conductor track and on a second layer at least one segment ( 71a - 71c ) is arranged a second conductor track and wherein the at least one segment of the conductor track on the first layer with the at least one segment of the conductor track on the second layer via contacts ( 60a - 60c . 61a - 61c ) is electrically conductively connected to one another in such a way that the interconnect segments connected to one another in an electrically conductive manner ( 70a - 70c . 71a - 71c ) at least one turn of a first coil ( 50 . 50a ), which as an antenna to the RFID / NFC interface ( 4 ) is connected and whose central coil axis is substantially parallel to the layers, and wherein the at least one carrier device ( 3 ) within the device module ( 2 ) is arranged.

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