Device for a vehicle for contactless data transmission

Description

[0001] The present invention relates to a device for a vehicle for contactless data transmission.

[0002] It is known from the prior art that devices for contactless data transmission, particularly NFC interfaces, utilize a transceiver circuit. For this purpose, an integrated circuit can be used, for example, to transmit information contactlessly via a signal sent to an antenna—via a first circuit. This integrated circuit can receive signals from the antenna via a second circuit. A filter circuit can also be provided between the integrated circuit and the antenna to filter the transmitted and / or received signal with respect to the communication frequency used. Typically, the antenna voltage is tapped within this filter circuit.Known solutions can have the disadvantage of higher leakage currents due to the reduced antenna voltage tapped within the filter circuit and the correspondingly lower impedances used for coupling out. A further disadvantage can be that providing the impedances requires greater technical effort.

[0003] US 2012 / 134444 A1 discloses a device for near-field communication, comprising an electronic processing means for data transmission. Two resistance elements are provided in a receive path of the device as voltage dividers to address the received signal for the receive terminal.

[0004] It is an object of the present invention to at least partially remedy the disadvantages described above. In particular, it is an object of the present invention to provide an improved and / or more cost-effective and / or energy-saving solution for a device for contactless data transmission, in particular for decoupling the antenna voltage.

[0005] The above object is achieved by a device having the features of the independent device claim. Further features and details of the invention emerge from the respective subclaims, the description, and the drawings.

[0006] The object is achieved in particular by a device, preferably an electrical or electronic circuit arrangement, for a vehicle for contactless data transmission between the vehicle and a mobile device, preferably for NFC communication of the vehicle with a mobile identification transmitter, comprising: at least (or exactly) one electronic processing means, such as an integrated circuit and / or a microcontroller and / or the like, for data transmission, at least one (or exactly two) transmission path(s), preferably each as an electrical current path, which connects a respective transmission connection of the processing means to an antenna in order to provide at least one transmission signal, in particular to generate it and / or to transmit it via the transmission path, at least one (or exactly two) reception path(s), preferably each as an electrical current path, which connects the antenna to a respective reception connection of the processing means in order to detect at least one reception signal and / or to transmit it via the reception path.

[0007] For example, a (single) transmit path can connect the antenna to a (single) transmit port of the processing means, and a (single) receive path can connect the antenna to a (single) receive port of the processing means. A first transmit path can also connect the antenna to a first transmit port of the processing means, and a second transmit path can connect the antenna to a second transmit port of the processing means. Furthermore, a first receive path can also connect the antenna to a first receive port of the processing means, and a second receive path can connect the antenna to a second receive port of the processing means.

[0008] This connection(s) can be understood as an electrical interconnection and / or electrical connection, which is, for example, permanently established (i.e., permanently electrically conductive and uninterrupted) or only temporarily established, for example, by electrical switches. Current paths are understood in particular to mean current branches of a circuit topology, which may not have any nodes or branches for the current along their extension. A current branch and / or the at least one receive path can also be connected to further current branches and / or to the at least one transmit path in order to provide a circuit for coupling out an antenna voltage.

[0009] It is also advantageous if the vehicle is designed as a motor vehicle, in particular as a hybrid vehicle or as an electric vehicle, preferably with a high-voltage electrical system and / or an electric motor. It may also be possible for the vehicle to be designed as a fuel cell vehicle and / or passenger vehicle and / or a semi-autonomous or autonomous vehicle. Advantageously, the vehicle has a security system which enables authentication, for example, through communication with a mobile device, such as an identification transmitter (ID transmitter) or a smartphone. Depending on the communication and / or the authentication, at least one function of the vehicle can be activated. If authentication of the mobile device is necessary for this, the function can be a security-relevant function, such as unlocking the vehicle or authorizing an engine start.Thus, the security system can also be designed as a passive access system, which initiates authentication and / or activation of the function upon detection of the mobile device or ID transmitter approaching the vehicle without active manual operation of the mobile device or ID transmitter. To this end, for example, a wake-up signal is repeatedly sent by the security system, which can be received by the mobile device or ID transmitter upon approach, and then triggers authentication. The function can also involve activating vehicle lights and / or operating (opening and / or closing) a hatch (e.g., front, rear, or side hatch or door). For example, the vehicle lights are automatically activated upon detection of approach, and / or the hatch is operated upon detection of a user gesture.

[0010] Communication can also occur, for example, via contactless data transmission. For this purpose, the vehicle can, for example, have the device according to the invention to implement an inductive coupling or the like with a corresponding communication interface of the mobile device. In this way, for example, authentication data can be transmitted via contactless data transmission. Contactless data transmission can also serve, if necessary, to activate the function in the vehicle. In particular, this involves data transmission via NFC (Near Field Communication) or RFID (Radio Frequency Identification). Furthermore, the communication can be implemented as unidirectional or bidirectional communication.

[0011] It may be possible for the device according to the invention to be integrated into a door handle of the vehicle. For example, the data transmission can be used to unlock or open a door (e.g., using the door handle) on the vehicle. For this purpose, a mobile device can be held against the door handle, for example, to carry out the data transmission.

[0012] In particular, it is provided that at least two (or exactly two) resistance elements are provided in each of the reception paths (i.e., in each of the reception paths), for example, at least partially also in a current branch connected to the reception path, in order to adjust the reception signal at the reception terminal. This has the advantage that a reliable and cost-effective arrangement can be used to, for example, quantitatively adjust the reception signal. In particular, an electrical voltage value of the reception signal is adjusted at the reception terminal. In other words, an arrangement for voltage adjustment, preferably a voltage divider, can be formed by the at least two resistance elements. Furthermore, the device according to the invention can offer the advantage of enabling power-saving operation.At least one of the resistance elements can be integrated in the reception path (i.e., possibly connected in series with other components in the reception path), and / or at least one of the resistance elements can be integrated into a current path which is connected to the reception path via a node.

[0013] For example, a first and second resistance element can be provided in a (first) receiving path, and optionally a (further) first and second resistance element can be provided in a second receiving path. The respective first and second resistance elements can be electrically connected (possibly directly) to each other and / or to the corresponding receiving path and / or to a respective fixed potential.

[0014] The resistance elements can, for example, be designed as electrical resistors to enable a (ohmic) voltage divider for the (ohmic) coupling of the antenna voltage (i.e., in particular, the received signal). For example, a voltage divider consisting of two resistance elements can be provided for each of the reception paths. In other words, at least or exactly two resistance elements can be provided per reception path.

[0015] Advantageously, the invention provides that one of the resistance elements of the respective receive path is directly connected to the antenna (in particular electrically) in order to tap the received signal directly at the antenna. For this purpose, the resistance element can, for example, be electrically connected to a node connected to the antenna and / or to the transmit path. Since the tap can be made directly at the antenna, the tapped antenna voltage (i.e., the received signal) can be relatively high. For example, the tapped antenna voltage is at least 10 volts, or at least 20 volts, or at least 30 volts. Accordingly, the resistance elements can have a relatively high resistance, which has the advantage that a leakage current can be reduced compared to a conventional solution.

[0016] According to the claimed invention, at least one of the resistance elements, together with the processing means, preferably a capacitance at the respective receiving terminal (in particular a so-called pin capacitance), forms a low-pass filter. The capacitance is provided in particular by the processing means at the receiving terminal and can thus be used, for example, in the manner of a capacitor. This enables further filtering of the signal in a particularly cost-effective and space-saving manner to suppress interfering frequencies.

[0017] Optionally, it is conceivable for the respective receiving path to have at least one of the resistance elements as a single electrical component, with the respective other resistance element preferably being integrated into a path branching off from the receiving path. The paths can thus each correspond to a current branch. The respective receiving path is, in particular, a receiver branch, and the respective transmitting path is, in particular, a transmitter branch. Each of these current branches can be a possible path for the current to take, i.e., a path in which a current can flow. Since only one voltage divider comprising two resistance elements may be required per receiving path, manufacturing costs can be significantly reduced.

[0018] Advantageously, the invention can provide for the at least two resistance elements to form a voltage divider to adjust the received signal (for example, a voltage value of the received signal) at the receiving terminal. Advantageously, the voltage divider can have a ratio of 22:1 and / or a maximum of (10 to 30):1. In other words, one of the resistance elements (for example, a first or second resistance element) can have a resistance value 10 to 30 times, preferably 22 times, that of the other (second or first) resistance element. In this way, the coupling can be carried out reliably and, in particular, a leakage current can be reduced.

[0019] Preferably, the resistance elements are each designed as a two-pole passive electrical component for implementing an ohmic resistance, for example, as a wired resistor or as an SMD resistor. The received signal is, for example, an electrical signal, such as an electrical voltage or the like.

[0020] According to a further advantage, it can be provided that one of the resistance elements is connected (in particular directly and / or immediately) to a fixed potential, preferably to a ground potential or a potential deviating from the ground potential, preferably of the processing means, in order to form a voltage divider against the fixed potential. The fixed potential can, for example, be (essentially) 0.9 V, which is provided in particular by the processing means, preferably by a receiver stage. For example, one of the resistance elements is connected directly to the fixed potential and the other of the resistance elements is connected directly to the receiving terminal. In this way, a compact and cost-effective circuit can be provided.

[0021] Advantageously, within the scope of the invention, it can be provided that the resistance elements (of a voltage divider) are electrically connected to one another, and from this connection between the resistance elements, the reception path leads directly to the reception terminal in order to adjust the reception signal at the reception terminal depending on an (antenna) voltage tapped at the antenna. The tapped voltage at the antenna is, for example, 30 V, so that the resistance elements can be designed with high resistance, thus reducing the leakage current.

[0022] A further advantage can be achieved within the scope of the invention if a coupling capacitor is provided in the respective transmission path, for example, to adjust a bandwidth of a filter circuit of the device. The coupling capacitor can be integrated in a path between the receiving port and the transmitting port in order to reduce interference signals and / or prevent a current flow from the receiving path into the transmitting path. The filter circuit is designed, for example, as a bandpass filter, so that a communication frequency is passed and / or frequencies outside the communication frequency are attenuated. The communication frequency is, for example, 13.56 MHz. In this way, reliable contactless data transmission can be provided.

[0023] Furthermore, within the scope of the invention, it is conceivable for two receive paths to symmetrically connect the respective receive connection to the antenna, wherein preferably two transmit paths to symmetrically connect the respective transmit connection to the antenna in order to provide symmetrical signal transmission of the signals between the antenna and the processing means, so that preferably the number of resistance elements integrated in the (all) receive paths is at least two in total and / or the number of resistance elements provided on the receive paths is at least four in total in order to adjust the receive signals at the respective receive connections. The symmetrical signal transmission ensures reliable and error-free data transmission.

[0024] Optionally, a filter circuit can be provided on the at least one transmission path to provide bandpass filtering. The bandpass filtering serves, in particular, to pass a frequency range around a center frequency of the filter circuit and to attenuate frequencies deviating from it. The width of this frequency range is defined, in particular, by the bandwidth of the filter circuit. Thus, reliable communication can be ensured.

[0025] Furthermore, it is optionally possible to provide a filter circuit, wherein the filter circuit, preferably a respective filter arrangement, is designed as a bandpass filter with a center frequency for an NFC frequency, preferably of at least approximately 13.56 MHz. The bandwidth can be, for example, 1 to 10 MHz. This enables reliable data transmission via NFC.

[0026] Furthermore, within the scope of the invention, it is optionally possible for the antenna to be designed as a near-field transmission coil. This also enables contactless data transmission, for example, using loosely coupled coils. A mobile device, such as an ID transmitter and / or smartphone, can be used as a communication participant for this data transmission.

[0027] Preferably, the antenna can be designed as a PCB antenna on a printed circuit board. PCB stands for printed circuit board. It can therefore be a printed antenna, thus enabling the device to be designed as space-saving as possible.

[0028] It may also be possible for the ratio of a first resistance element to a second resistance element to be in the range of 10 to 50, preferably 15 to 25, more preferably 20 to 24, and particularly preferably substantially 22. This can apply to both the first and second resistance elements (of a first voltage divider) in a first reception path and optionally to the first and second resistance elements (of a second voltage divider) in a second reception path. This enables particularly energy-efficient decoupling of the received signal.

[0029] Furthermore, within the scope of the invention, it can be provided that at least one of the resistance elements, preferably a first and / or second resistance element, has an electrical resistance of at least 5 kOhm, preferably at least 10 kOhm. This can significantly reduce the leakage current.

[0030] Further advantages, features, and details of the invention will become apparent from the following description, which describes embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. They show: Fig. 1 a schematic side view of a vehicle with a device according to the invention, Fig. 2 a schematic circuit diagram of a device according to the invention.

[0031] In the following figures, identical reference numerals are used for the same technical features, even in different embodiments.

[0032] In Fig. 11 schematically shows a side view of a vehicle 1. The vehicle can have vehicle electronics 2, which, for example, provides a security system 4 of the vehicle. Furthermore, a vehicle component 3, such as a door handle 3, can be provided on the vehicle. A device 10 according to the invention, in particular an NFC interface device 10, can be integrated into the vehicle component 3. This makes it possible to activate a function on the vehicle via contactless data transmission, for example from a mobile device 200 to the device 10 according to the invention. For this purpose, the data can be, for example, authentication data, which, after being received from the device 200, is transmitted from the device 10 according to the invention to the vehicle electronics 2. The authentication data can then be compared, for example, with a specification, for example with a secret code, in order to authenticate the mobile device 200.

[0033] In Fig. 2 A schematic circuit diagram of a device 10 according to the invention for a vehicle 1 is shown, which device serves for contactless data transmission between the vehicle 1 and a mobile device 200. The data transmission preferably involves communication, preferably NFC communication, between the vehicle 1 and the mobile device 200, such as an identification transmitter 200. In this way, data, such as authentication data, can be reliably transmitted from the mobile device 200 to the vehicle 1. The identification transmitter 200 serves in particular for authentication and can, for example, also be provided by a smartphone or mobile device or the like.

[0034] The device 10 according to the invention can comprise a circuit that has at least one electronic component. The electronic component(s) are connected, for example, to a circuit board with conductor tracks. The conductor tracks can form current paths for interconnecting the components. For example, Fig. 2 A circuit diagram for such a connection is shown schematically.

[0035] At least one electronic processing means 50 can be provided for data transmission in the device 10 according to the invention. In addition, at least one transmission path UTx can be used, which connects a respective transmission connection Tx of the processing means 50 to an antenna 80 in order to provide at least one transmission signal. At least one reception path URx can also be used, which connects the antenna 80 to a respective reception connection Rx of the processing means 50 in order to detect at least one reception signal. At least two resistance elements R can be provided in each reception path URx in order to adjust the reception signal at the reception connection Rx. In this case, one of the resistance elements R in the respective reception path URx can be connected directly to the antenna 80 in order to tap the reception signal directly at the antenna. In the present case, the direct connection consists in a connection to electrical connection points 70 ora connection arrangement 70 of the antenna 80. The direct connection implies in particular that no further electronic components are provided in series between the antenna 80, in particular the connection arrangement 70 of the antenna 80, and one of the resistance elements R.

[0036] It may also be possible for the respective receiving path URx to have at least one of the resistance elements R (in this case, first resistance elements R1, R1') as a single electrical component, wherein the respective other resistance element R (in this case, second resistance elements R2, R2') is preferably integrated into a path branching off from the receiving path URx. Furthermore, the at least two resistance elements R can form a voltage divider to adjust the received signal at the receiving terminal Rx. In this case, one of the resistance elements R, namely in this case the second resistance elements R2, R2', can be connected to a fixed potential 90, preferably to a ground potential 90' or a potential 90 deviating from the ground potential 90', preferably of the processing means 50, in order to form a voltage divider against the fixed potential 90.

[0037] As also shown, the resistance elements R can each be electrically connected to one another, and from this connection between the resistance elements R, the reception path URx can lead directly to the reception terminal Rx in order to adjust the reception signal as a function of a voltage tapped at the antenna 80 at the reception terminal Rx. In the example shown, R1 is connected to R2 and R1' is connected to R2'.

[0038] Furthermore, it is conceivable that a coupling capacitor 60 is provided in the respective transmission path UTx in order to adjust a bandwidth of a filter circuit 20 of the device 10, wherein the coupling capacitor 60 is integrated in a path between the reception terminal Rx and the transmission terminal Tx in order to reduce interference signals and / or to prevent a current flow from the reception path URx into the transmission path UTx.

[0039] In Fig. 2It is further provided that two receive paths URx symmetrically connect the respective receive terminal Rx to the antenna 80, wherein two transmit paths UTx symmetrically connect the respective transmit terminal Tx to the antenna 80 in order to provide symmetrical signal transmission of the signals between the antenna 80 and the processing means 50. Accordingly, two resistance elements R1, R2 and R1', R2' or one voltage divider each can be provided for each receive path URx.

[0040] Furthermore, a filter circuit 20 is provided on the at least one transmission path UTx to provide bandpass filtering. Thus, the filter circuit 20 can utilize multiple electronic components, such as capacitors C and / or capacitors 60, to provide filtering of the transmission and / or reception signal. For this purpose, the filter circuit 20 can have a first filter arrangement 20.1 and a second filter arrangement 20.2 designed symmetrically thereto, each, for example, with the same electronic components but in different reception and / or transmission paths. A first sub-array 12 and a second sub-array 13 can also be provided for each filter arrangement 20.1, 20.2. Each of the sub-arrays 12, 13 can, for example, form a resonant circuit, which are each coupled to one another by a capacitor 60 to provide a bandpass filter. For this purpose, the sub-arrays 12, 13 can, for example, each have filter elements.Shown by way of example are a first filter element 41 of the first sub-array 12 of the first filter arrangement 20.1 and a second filter element 42 of the first sub-array 12 of the second filter arrangement 20.2. The filter elements 41, 42 each comprise, for example, an RL element (consisting of a resistor and a coil) or an RL element (consisting of a resistor and a coil).

[0041] If necessary, at least one of the resistance elements R can form a low-pass filter together with the processing means 50, preferably a capacitor at the receiving terminal Rx. It is also possible for the antenna 80 to be designed as a near-field transmission coil and / or as a PCB antenna. This allows data transmission to be optimized, particularly as NFC data transmission.

[0042] The above explanation of the embodiments describes the present invention exclusively by way of example. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention as defined in the claims. List of reference symbols

[0043] 1Vehicle 2Vehicle electronics 3Vehicle component, door handle 4Security system 10Device, NFC interface device 12First sub-array, first oscillating circuit, serial oscillating circuit 13Second sub-array, second oscillating circuit, parallel oscillating circuit 20Filter circuit 20.1First filter arrangement 20.2Second filter arrangement 41First filter element, first RL element 42Second filter element, second RL element 50Processing agents 60Coupling unit, coupling capacitor 70Connection point, connection arrangement 80Antenna 90 fixed potential, ground potential 200 mobile device 90' ground potential R resistance element Rx receive connection, receiver connection R1 first resistance element R2 second resistance element URx receive path, receiver branch R1' first symmetrical resistance element R2' second symmetrical resistance element Tx transmit connection, transmitter connection UTx transmit path, transmitter branch

Claims

1. Device (10) for a vehicle (1) for contactless data transmission between the vehicle (1) and a mobile device (200), preferably for NFC communication of the vehicle (1) with an identification transmitter (200): - at least one electronic processing means (50) for data transmission, - at least one transmission path (UTx), which connects a respective transmission terminal (Tx) of the processing means (50) to an antenna (80) in order to provide at least one transmission signal, - at least one receive path (URx) which connects the antenna (80) to a respective receive terminal (Rx) of the processing means (50) in order to detect at least one receive signal, wherein at least two resistor elements (R) are provided in each case in the receive path (URx) in order to adjust the receive signal at the receive terminal (Rx), wherein one of the resistor elements (R) of the respective receive path (URx) is connected directly to the antenna (80) in order to tap the receive signal directly at the antenna, and wherein at least one of the resistor elements (R) forms a low-pass filter together with the processing means (50), preferably a capacitance at the receiving terminal (Rx).

2. Device (10) according to claim 1, characterized in that the respective receive path (URx) has at least one of the resistor elements (R) as the only electrical component, the other resistor element (R) in each case preferably being integrated in a path branching off from the receive path (URx).

3. Device (10) according to one of the preceding claims, characterized in that the at least two resistor elements (R) form a voltage divider in order to adjust the receive signal at the receive terminal (Rx).

4. Device (10) according to one of the preceding claims, characterized in that in each case one of the resistor elements (R) is connected to a fixed potential (90), preferably to a ground potential (90') or to a potential (90) deviating from the ground potential (90'), preferably of the processing means (50), in order to form a voltage divider with respect to the fixed potential (90).

5. Device (10) according to one of the preceding claims, characterized in that the resistor elements (R) are electrically connected to one another in each case, and starting from this connection between the resistor elements (R), the receive path (URx) leads directly to the receive terminal (Rx) in order to adjust the receive signal as a function of a voltage tapped at the receive terminal (Rx) on the antenna (80).

6. Device (10) according to one of the preceding claims, characterized in that a coupling capacitor (60) is provided in the respective transmission path (UTx) in order to adjust a bandwidth of a filter circuit (20) of the device (10), the coupling capacitor (60) being integrated in a path between the receive terminal (Rx) and the transmission terminal (Tx) in each case in order to reduce interference signals and / or prevent a current flow from the receive path (URx) into the transmission path (UTx).

7. Device (10) according to one of the preceding claims, characterized in that two receive paths (URx) symmetrically connect the respective receive terminal (Rx) to the antenna (80), wherein preferably two transmission paths (UTx) symmetrically connect the respective transmission terminal (Tx) to the antenna (80) in order to provide symmetrical signal transmission of the signals between the antenna (80) and the processing means (50).

8. Device (10) according to one of the preceding claims, characterized in that a filter circuit (20) is provided on the at least one transmission path (UTx) in order to provide bandpass filtering.

9. Device (10) according to one of the preceding claims, characterized in that a filter circuit (20) is provided, the filter circuit (20), preferably a respective filter arrangement (20.1, 20.2), being designed as a bandpass filter with a center frequency (F0) for an NFC frequency, preferably of at least almost 13.56 MHz.

10. Device (10) according to one of the preceding claims, characterized in that the antenna (80) is designed as a near-field transmission coil.

11. Device (10) according to one of the preceding claims, characterized in that the antenna (80) is formed on a printed circuit board (11) as a PCB antenna.

12. Device (10) according to one of the preceding claims, characterized in that in each case a ratio of a first resistance element (R1) to a second resistance element (R2) is formed in the range from 10 to 50, preferably 15 to 25, preferably 20 to 24.

13. Device (10) according to one of the preceding claims, characterized in that at least one of the resistor elements (R), preferably a first and / or second resistor element (R1, R2), has an electrical resistance of at least 5 kOhm, preferably at least 10 kOhm.