Chip card reading arrangement

A chip card reading arrangement is provided including a chip card reading device including a data processing circuit and a reader antenna coupled to the data processing circuit arranged at a surface of the chip card reading device for placing a chip card to communicate with the chip card reading device via the reader antenna. The data processing circuit is configured to process at least one of signals received via the reader antenna and signals to be transmitted via the reader antenna. The chip card reading arrangement further includes an antenna structure including an antenna body, a first antenna and a second antenna coupled to the first antenna and surrounded by the first antenna. The antenna structure is arranged on and fixed to the surface of the chip card reading device such that the reader antenna surrounds the second antenna.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application Serial No. 10 2015 102 288.5, which was filed Feb. 18, 2015, and is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to chip card reading arrangements.

BACKGROUND

Chip cards come in various formats such as ID-1 and ID-2 but may also include much smaller transponders such as RFID (radio-frequency identification) transponders. Accordingly, there are large variations in the size of the antennas between different chip cards and a reading device suited for a certain antenna size may have a poor communication performance for another, e.g. much smaller, antenna size. Therefore, it may be desirable to adapt a reader designed for a certain antenna size to a different, e.g. much smaller, antenna size.

SUMMARY

A chip card reading arrangement is provided including a chip card reading device including a data processing circuit and a reader antenna coupled to the data processing circuit arranged at a surface of the chip card reading device for placing a chip card to communicate with the chip card reading device via the reader antenna. The data processing circuit is configured to process at least one of signals received via the reader antenna and signals to be transmitted via the reader antenna. The chip card reading arrangement further includes an antenna structure including an antenna body, a first antenna and a second antenna coupled to the first antenna and surrounded by the first antenna. The antenna structure is arranged on and fixed to the surface of the chip card reading device such that the reader antenna surrounds the second antenna.

DESCRIPTION

The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and aspects of this disclosure in which the invention may be practiced. Other aspects may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. The various aspects of this disclosure are not necessarily mutually exclusive, as some aspects of this disclosure can be combined with one or more other aspects of this disclosure to form new aspects.

FIG. 1shows a communication arrangement100including a reader device102(or reader) and a chip card101. The reader includes an antenna103which is for example arranged in a housing onto which the chip card101is placed, i.e. around the detection area. The reader antenna103may be round (as shown) or rectangular and may for example have a diameter (or width) of 5 cm to 15 cm.

The chip card101includes a chip card module104and an antenna105to communicate with the reader device102via the reader antenna103.

The antenna103of the reader device102is for example a large sized PCD antenna that is suited to the particular application. Transport readers for instance, are designed to operate with ID1 and ID2 cards and provide good communication performance with cards of these dimensions. The dimensions of these ID1, ID2 etc. cards are several cm and can be found in the ISO/IEC 7810. However, such a reader is not designed to operate in combination with small RFID (radio-frequency identification) transponders. Therefore, the performance of the communication with small scaled transponders is poor. In some cases, a well performing reader is able to communicate with a small transponder but only at corner positions of the reader PCD. Thus, it may not be possible to ensure a successful communication at the overall antenna area of the reader antenna103. In other words, due to the limited coupling factor between the antenna of the reader (also referred to as PCD for proximity coupling device) and the antenna of the chip card (also referred to as PICC for proximity integrated circuit card) the reader devices may be blind at its center position and not able to communicate with a small transponder, i.e. with a chip card with small antenna, e.g. of an RFID transponder.

For example, active modulation at 13.56 MHz enables the possibility to combine the RFID technology into small scaled devices, such as a μSD cards, but it may then not be possible to communicate with readers with large PCD antennas (e.g. larger than 10×10 cm) in centered position.

FIG. 2illustrates the magnetic field distribution of a cross section of an antenna of a reader as illustrated inFIG. 1.

First areas201(also referred to as hot-spots) with high magnetic field strength are formed around the wires forming the antenna. Second areas202around the antenna wires with lower magnetic field strength than the first areas201may for example still provide sufficient magnetic field strength to ensure a radio communication. However, a third area203with lower magnetic field strength than the second area202and a fourth area204with even lower magnetic field strength may for example not provide sufficient magnetic field strength for a radio communication such that for example a chip card with a small antenna arranged at a center axis205may not successfully communicate with the reader.

This issue may for example be addressed by a reading device as illustrated inFIG. 3.

FIG. 3shows a chip card reading arrangement300according to an embodiment.

The chip card reading arrangement300includes a chip card reading device301and an antenna structure302.

The chip card reading device301includes a data processing circuit303and a reader antenna304coupled to the data processing circuit arranged at a surface305of the chip card reading device for placing a chip card to communicate with the chip card reading device301via the reader antenna304. The data processing circuit303is configured to process at least one of signals received via the reader antenna304and signals to be transmitted via the reader antenna304.

The antenna structure includes an antenna body306, a first antenna307and a second antenna308coupled to the first antenna307and surrounded by the first antenna307.

The antenna structure302is arranged on and fixed to the surface305of the chip card reading device301such that the reader antenna304surrounds the second antenna308.

In other words, a chip card reader is provided with an antenna structure (also referred to as antenna upgrade in the following) which includes at least one inner antenna that lies within the area surrounded by an outer antenna of the antenna structure as well as the area surrounded by the reader antenna. Illustratively, the inner antenna may act as a concentrator the magnetic field emitted by the reader antenna to a smaller area. The antenna structure can be seen as booster antenna structure which is arranged on reader instead of within a chip card.

It should be noted that the reader antenna and the second antenna may lie in different planes when the antenna structure is placed above the surface at which the reader antenna is located. Also the first antenna and the second antenna do not necessarily lie within the same plane (but may for example be part of different layers of the body of the antenna structure). Accordingly, the reader antenna or first antenna, respectively, surrounding the second antenna may be understood as the reader antenna/first antenna surrounding the second antenna when shifted to the same plane (e.g. perpendicular to the surface of the chip card reading device and/or the axis of the reader antenna or the second antenna. The shifting distance is small with respect to the diameter of the reader antenna or the first antenna, respectively, e.g. less than 5% or 10% than the diameter). The reader antenna surrounding the second antenna may also be understood as the second antenna lying in a detection area of the chip card reading device defined by the reading antenna.

For example, an antenna structure is provided which can be applied directly onto the detection area of a standard RFID reader. It includes a large pickup coil (i.e. an outer antenna with a similar dimension as reader antenna) and one (or more) smaller coupling structures (i.e. inner antennas). Due to the antenna form, the magnetic field is focused to a hotspot (small coupling structure) that is for example arranged in the center of the detection area surrounded by the reader antenna.

It should be noted that the second antenna does not necessarily have to be surrounded by the first antenna and the reader antenna but is for example surrounded by only one or none of them. The second antenna is for example placed near the first antenna and/or the reader antenna and may but may or may not be surrounded by them. In this case, there may for example be a marking on the surface of antenna body of the antenna structure indicating a position near the second antenna to be a position where a small transponder, e.g. of the RFID form factor, should be placed. For example, an area of a surface of the antenna body below which the second antenna is arranged may be marked in this way.

Accordingly, according to one embodiment, a chip card reading arrangement is provided including a chip card reading device including a data processing circuit and a reader antenna coupled to the data processing circuit arranged at a surface of the chip card reading device for placing a chip card to communicate with the chip card reading device via the reader antenna, wherein the data processing circuit is configured to process at least one of signals received via the reader antenna and signals to be transmitted via the reader antenna and an antenna structure including an antenna body, a first antenna and a second antenna coupled to the first antenna and smaller than the first antenna and the reader antenna.

According to one embodiment, the chip card reading device further includes a housing wherein the surface of the chip card reading device is a surface of the housing.

According to one embodiment, the antenna body includes a substrate, e.g. a printed circuit board.

According to one embodiment, the antenna body includes a housing of the antenna structure.

The housing (of the antenna structure) is for example, arranged on and fixed to the surface of the chip card reading device.

According to one embodiment, the antenna structure is fixed to the surface of the chip card reading device by fastening means, e.g. including at least one of one or more screws or one or more nut and bolt arrangements.

According to one embodiment, the antenna structure is fixed to the surface of the chip card reading device by an adhesive.

According to one embodiment, the first antenna includes one or more first windings and the second antenna includes one or more second windings lying within the one or more first windings.

According to one embodiment, the reader antenna includes one or more reader antenna windings and the second antenna includes one or more second windings and the antenna structure is arranged on and fixed to the surface of the chip card reading device such that the one or more second windings lie within the one or more reader antenna windings.

According to one embodiment, the antenna structure includes a plurality of second antennas coupled to the first antenna and surrounded by the first antenna and the antenna structure is arranged on and fixed to the surface of the chip card reading device such that the reader antenna surrounds the second antennas.

The antenna structure is for example configured to concentrate magnetic power emitted by the reader antenna.

For example, the antenna structure is configured to concentrate magnetic power emitted by the reader antenna to a central area of the antenna structure (e.g. corresponding to the second antenna).

According to one embodiment, the antenna structure is configured such that the first antenna receives power from the reader antenna and provides the received power to the second antenna and the second antenna emits the received power in form of magnetic power.

According to one embodiment, the antenna structure is arranged on and fixed to the surface of the chip card reading device such that the first antenna lies above the reader antenna.

The first antenna and the reader antenna may have substantially the same size.

According to one embodiment, the first antenna is for example larger than the second antenna.

According to one embodiment, the antenna structure includes a surface for placing a chip card to communicate with the chip card reading device to communicate with the chip card reading device via the first antenna, the second antenna and the reader antenna.

According to one embodiment, the first antenna is configured to forward signals to be transmitted by the chip card reading device (e.g. to a chip card) to the second antenna and is configured to forward signals to be received by the chip card reading device (e.g. from a chip card) to the reader antenna.

In the following, embodiments are described in more detail.

FIG. 4shows a communication arrangement400according to an embodiment.

Similarly to the communication arrangement100ofFIG. 1, the communication arrangement400includes a reader device402(or reader) and a chip card401. The reader device402includes an antenna403(also referred to as PCD antenna). The antenna403is galvanically coupled to a reader IC (integrated circuit)404via a matching network405and a filter406.

In this example, the chip card401is a small RFID device which may for example not be able to communicate via the PCD antenna403with the reading device402if it is placed near a center of the PCD antenna403. However, a PCD upgrade407is arranged over the PCD antenna403, e.g. over a detection area or detection surface of the reader402defined by the PCD antenna. The PCD upgrade407, also generally referred to as antenna structure, has a high (magnetic) coupling coefficient with the PCD antenna403and is formed such that it concentrates the magnetic field of the PCD antenna403to a smaller area than the detection area such that the communication between the chip card401and the reader402via the PCD upgrade407and the PCD antenna403is possible.

The PCD upgrade407is fixed to the reader402. For example, the PCD upgrade407includes a carrier (e.g. a printed circuit board) and/or a housing which is fixed to a surface, e.g. of a housing, of the reader402, e.g. fixed by an adhesive or fixed with mechanical fastening means (also referred to as a “fastener”) such as screws etc., to adapt the reader402to the usage with smaller-sized antennas than its PCD antenna403.

The PCD upgrade407for example has the form as illustrated inFIG. 5.

FIG. 5shows a chip card reader arrangement500.

The chip card reader arrangement500includes a reader501including a PCD antenna502. Over the PCD antenna502, a PCD upgrade503is arranged. The PCD upgrade503includes an outer (larger) antenna504(also referred to as pickup coil) and a smaller (inner) antenna505(also referred to as coupling structure) which are galvanically coupled to each other by wires506. In this example, each of the antennas504,505is formed by one winding with a respective capacitor507,508coupled in between each winding but each antenna can include a plurality of windings. The inner antenna505can be seen to form a coupling structure for magnetically coupling with a chip card having a small antenna (i.e. of a dimension significantly smaller than the PCD antenna502).

The antenna structure, i.e. the PCD upgrade503, can be tuned in a way that focuses the total power into the coupling structure. Therefore, a communication with a small scaled transponder is feasible, in this case however only at the center position of the PCD upgrade503.

FIG. 6illustrates the magnetic field distribution of a cross section of an arrangement of a PCD upgrade601placed on a PCD antenna602, e.g. corresponding to the PCD upgrade504and the PCD antenna502. In this example, the outer antenna and the inner antenna of the PCD upgrade601each have a plurality of windings.

As can be seen, the PCD upgrade601forces the total power into the coupling structure, i.e. into a central area indicated by areas603,604,605,606of (when going farther away from the center) decreasing magnetic field strength.

To allow communication with a small scaled chip cards, e.g. including RFID tags, which are not necessarily arranged at the center of the PCD upgrade and PCD antenna, the antenna structure (i.e. the PCD upgrade) may be tuned in a way to split the available power to different locations, such that the coupling structure (inner antenna) does not propagate the maximum of available power.

Basically, both antenna resonant circuits can be matched individually. Which matching is finally chosen depends on the application. Thus, the field strength distribution can be adjusted for the given operating volume. The matching is done by selecting an appropriate capacitor value (e.g. of capacitors507,508) depending on both inductances of the PCD upgrade structure.

The splitting of available power is illustrated inFIG. 7.

FIG. 7illustrates the magnetic field distribution of a cross section of an arrangement of a PCD upgrade placed on a PCD antenna which is tuned such that the magnetic power is distributed over various locations.

The resulting magnetic field strength distribution can be seen as a combination of the magnetic field strength distributions ofFIG. 2andFIG. 6, i.e. hot-spots701are formed in the center of the PCD upgrade as well as around the wires of the outer antenna (including areas of decreased magnetic field strength when leaving these hot-spots as described with reference toFIG. 2andFIG. 6).

This configuration allows ID1 cards as well as small scaled RFID transponders to communicate with the reader device. Moreover miniaturized transponders can be detected at the overall spanned PCD area, i.e. the detection area as defined (i.e. surrounded) by the PCD antenna.

In a similar way as illustrated inFIG. 7, a higher number of hot-spots (e.g. more than one center hot-spot) can be implemented. By splitting the available power to several hot spots a large detection area can be generated.

Various examples of the PCD upgrade407are illustrated inFIG. 8toFIG. 11.

FIG. 8shows a communication arrangement800. Similarly to the communication arrangement400, the communication arrangement800includes a reader801having a PCD antenna802, a PCD upgrade803and a chip card804with a small antenna805, e.g. an RFID device.

Similarly to the PCD upgrade504ofFIG. 5, the PCD upgrade803includes an outer antenna806and an inner antenna807which are coupled to each other (connected in parallel). The outer antenna806corresponds to a serial connection of a first inductance808, a capacitor809and a first resistor810. The inner antenna807corresponds to a serial connection of a second inductance811and a second resistor812. The PCD antenna802and the outer antenna808are coupled with a coupling factor k1and the inner antenna807and the antenna805of the chip card804are coupled with a coupling factor k2.

The PCD antenna802and the antenna805of the chip card804are coupled with a coupling factor k3. The coupling factor k3is much smaller than k2and k1. This results from the fact that the PCD antenna802is much larger than the RFID device804while the inner antenna807and the antenna805of the chip card804are geometrically matched.

FIG. 9shows communication arrangement900, which is a different view of the communication arrangement800.

InFIG. 9, a reader901corresponds to the reader801, a PCD antenna902corresponds to the reader antenna802, a PCD upgrade903corresponds to the PCD upgrade803and an RFID device907corresponds to the chip card804. The PCD upgrade903includes an outer antenna904corresponding to the outer antenna806which includes a capacitor906corresponding to the capacitor809and an inner antenna905corresponding to the inner antenna807.

FIG. 10shows a communication arrangement1000. Similarly to the communication arrangement400, the communication arrangement1000includes a reader1001having a PCD antenna1002, a PCD upgrade1003and a chip card1004with a small antenna1005, e.g. an RFID device.

Similarly to the PCD upgrade504ofFIG. 5, the PCD upgrade1003includes an outer antenna1006and an inner antenna1007which are coupled to each other (connected in parallel). The outer antenna1006corresponds to a serial connection of a first inductance1008and a first resistor1010. The inner antenna1007corresponds to a serial connection of a second inductance1011and a second resistor1012. Further, a capacitor1009is connected in parallel to the outer antenna1006and the inner antenna1007. The PCD antenna1002and the outer antenna1008are coupled with a coupling factor k1and the inner antenna1007and the antenna1005of the chip card1004are coupled with a coupling factor k2. The PCD antenna1002and the antenna1005of the chip card1004are coupled with a coupling factor k3smaller than the coupling factors k1and k2.

FIG. 11shows communication arrangement1100, which is a different view of the communication arrangement1000.

InFIG. 11, a reader1101corresponds to the reader1001, a PCD antenna1102corresponds to the reader antenna1002, a PCD upgrade1103corresponds to the PCD upgrade1003and an RFID device1107corresponds to the chip card1004. The PCD upgrade1103includes an outer antenna1104corresponding to the outer antenna1006, an inner antenna1105corresponding to the inner antenna1007and a capacitor1106corresponding to the capacitor1009.

FIG. 12shows a communication arrangement1200. Similarly to the communication arrangement400, the communication arrangement1200includes a reader1201having a PCD antenna1202, a PCD upgrade1203and a chip card1204with a small antenna1205, e.g. an RFID device.

Similarly to the PCD upgrade504ofFIG. 5, the PCD upgrade1203includes an outer antenna1206and an inner antenna1207which are coupled to each other (namely connected in parallel). The outer antenna1206corresponds to a serial connection of a first inductance1208and a first resistor1210and includes a first capacitor1209. The inner antenna1207corresponds to a serial connection of a second inductance1211and a second resistor1212. Further, a capacitor1213is connected in parallel to the outer antenna1206and the inner antenna1207. The PCD antenna1202and the outer antenna1208are coupled with a coupling factor k1and the inner antenna1207and the antenna1205of the chip card1204are coupled with a coupling factor k2. The PCD antenna1202and the antenna1205of the chip card1204are coupled with a coupling factor k3smaller than the coupling factors k1and k2.

FIG. 13shows a different view of the communication arrangement1200.

InFIG. 13, a reader1301corresponds to the reader1201, a PCD antenna1302corresponds to the reader antenna1202, a PCD upgrade1303corresponds to the PCD upgrade1203and an RFID device1307corresponds to the chip card1204. The PCD upgrade1303includes an outer antenna1304corresponding to the outer antenna1206, an inner antenna1305corresponding to the inner antenna1207, a first capacitor1306corresponding to the first capacitor1209and a second capacitor1308corresponding to the second capacitor1213.

FIG. 14shows an example of a communication arrangement1400in which the PCD upgrade has a plurality of inner antennas, such that a plurality of hotspots are formed.

Similarly to the communication arrangement1300ofFIG. 13, the communication arrangement1400includes a reader1401, a PCD antenna1402, a PCD upgrade1403and an RFID device1407. As the PCD upgrade1303, the PCD upgrade1403includes an outer antenna1404including a first capacitor1406. However, in this example, the PCD upgrade1403includes a plurality of inner antennas1405connected to the outer antenna1404. For each inner antenna1405, the PCD upgrade1403includes a second capacitor1408similarly to the second capacitor1308. The RFID device1407is in this example arranged over the topmost inner antenna inFIG. 14.

In the following, results of experiments for validation of the functionality of the PCG upgrade are given. The experiments are based on a setup in which the reader antenna upgrade (implemented on a printed circuit board) is directly arranged at the top of the reader antenna (also implemented on a printed circuit board and connected via cable and e.g. a balun with the other reader components; the reader antenna is in this example a 50 Ohm matched antenna). The chip card is in this example a μSIM (e.g. arranged within a mobile phone), i.e. communication is to be performed between the reader and the μSIM transponder. It can be seen that without reader antenna upgrade the μSIM transponder has to be arranged close to the PCD antenna for allowing communication and a communication is not possible when the μSIM is arranged at a center position of the PCD antenna.

In following the results of a measurement of the reading distance to the μSIM transponder as well as the reading distance to ID1 cards from the reader antenna are given.

Reading distance measurement with ID1 and μSIMon custom built 50 Ohm reader antenna. In this measurement the position of the chip card is centered.

Reading distance measurement with ID1 and μSIMon custom built 50 Ohm reader antenna. In this measurement the position of the chip card is arranged at a corner of the PCD antenna.

Thus, the usage of PCD upgrade has no draw back compared to the usage of the reader without PCD upgrade with regard to communication at a corner position.