Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
  • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
  • G06K19/0723—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
  • G06K19/0726—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
  • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
  • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
  • G06K19/0723—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/08—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes

Definitions

• the invention relates to a high-frequency identification medium with a passive electronic data carrier according to the preamble of claim 1, with a receiving antenna for receiving operating energy and for the contactless transmission of HF signals to an assigned writing and reading station with a transmitting antenna which has a carrier frequency fr of more than 1 MHz.
• a receiving antenna for receiving operating energy and for the contactless transmission of HF signals to an assigned writing and reading station with a transmitting antenna which has a carrier frequency fr of more than 1 MHz.
• High frequencies with a system clock or carrier frequency of over 1 MHz are necessary in order to achieve high communication and transmission performance.
• An example of this is the Legic system from Kaba AG.
• the tuning of the identification medium to the carrier frequency is only possible to a very limited extent.
• the object of the invention is to provide an identification medium which has significant improvements with regard to these problems. This object is achieved with an identification medium according to claim 1, with which much better transmission properties can now be achieved.
• the highest possible input voltage on the identification medium or on the data carrier is not generated by antennas with high inductance, but on the contrary, the input voltage and inductance, i.e. the number of turns of the antenna is reduced and the total capacity is correspondingly increased by inserting an additional external capacitance Ce, which is greater than the internal capacitance Ci of the data carrier MI.
• the receiver frequency of the identification medium can be set much better and more precisely to the carrier frequency.
• the receiver frequency is largely constant and is less dependent on external influences.
• Fig. 1 an inventive identification medium IM with external capacity
• Fig. 2 is an associated write and read station WR
• Fig. 3 shows another example of an identification medium with coded communication
• Fig. 4 shows an example with a double antenna and assigned external capacities
• Fig. 6 shows the dependence of the receiver frequency on the coupling
• Fig. 9 shows a small identification medium with a ferrite antenna in the form of a bracelet
• Fig. 10 shows a small-sized key chain as an identification medium.
• FIGS. 1 and 3 show examples of identification media IM according to the invention and FIG. 2 shows an assigned writing and reading station WR.
• the schematic representation of FIG. 1 shows an identification medium IM with a passive electronic data carrier MI, which contains a processor 11, control electronics 13 and a memory 12.
• a receiving antenna 15 with inductance L is used to receive operating energy 20a and for the contactless transmission of RF signals (20) to the assigned reading or writing and reading station WR.
• An external capacitance Ce is connected in parallel with the receiving antenna 15, this capacitance Ce being greater than the internal capacitance Ci of the data carrier MI.
• the inductance L of the antenna and the external capacitance Ce are matched in such a way that a natural frequency f of the identification medium is reached which corresponds to the carrier frequency fr.
• the carrier frequency fr is determined by the writing and reading station WR and its transmitting antenna 24.
• the assigned reading station or writing and reading station WR generates the system clock, the carrier frequency fr, which is transmitted to the identification media IM by the transmitting antenna 24. Both the energy 20a, which is required for the operation of the identification medium IM, and the data 20b from the read and write station WR are transferred to the Identification medium IM transmitted.
• the carrier frequency In order to achieve high communication performance, the carrier frequency must be in the range above 1 MHz, preferably between 5 and 20 MHz and not above 30 MHz. This is due, among other things, to the fact that the best possible transmission, ie strong coupling must be achieved in the close range, while as little power as possible should be emitted in the far range.
• this near-field range is of the order of magnitude between one and 100 meters and thus in a range that is important for identification media.
• a favorable carrier frequency is, for example, in the ISM band of 13.56 MHz, with which optimal transmission properties can be achieved for communication distances of up to several meters.
• FIG. 5 illustrates the dependence of the communication power KL on the correspondence of the carrier frequency for the writing and reading station and the transmitting antenna 24 with the natural frequency f of the identification medium and the receiving antenna 15.
• the communication services are, for example, the range R and the solid angle W of the communication and the angular range W2 of the relative position of the receiving antenna 15 to the field of the antenna 24, in which communication is possible.
• FIG. 6 shows the dependence of the natural frequency f on the antenna coupling AK or on the distance of the two antennas.
• the natural frequency fl of a previous identification medium drops very sharply with increasing coupling AK, e.g. at 10%.
• the frequency response f2 of a new antenna according to the invention shows a significantly smaller drop by e.g. only 1 to 3%. That a permissible tolerance range Df of e.g. ⁇ 2% can be achieved much better with the stable new antenna according to curve f2 than with the unstable previous antenna according to curve fl.
• Df e.g. ⁇ 2%
• the stable external capacitance Ce with high quality is therefore preferably chosen to be several times larger than the internal capacitance Ci, e.g. 5 to 10 times larger.
• This quality factor Q should preferably be at least 50.
• the external capacitance Ce with high quality, constancy and with precisely defined and selectable capacitance values, and thus a correspondingly constant, defined and selectable frequency f is achieved, which, as explained, relates to the high communication performance KL leads.
• the concept according to the invention also achieves great advantages with regard to the design and production of identification media. Since the natural frequency f is much more precisely defined and also measurable, it can also be matched much more precisely to the carrier frequency fr. The setting of a desired setpoint for the natural frequency f is possible much more precisely and easily, since the additional external capacitance Ce has a precisely defined and constant value, which can be selected as desired.
• FIG. 3 illustrates an example of an identification medium for coded communication.
• the data carrier MI preferably in the form of an ASIC chip 16, here contains a backup capacitor 17 for storing the received energy and for bridging transmission pauses, a voltage regulator 3, a clock processor 4, a reception demodulator 5, a transmission modulator 6 and a coding and communication logic 7 and a writable EEPROM memory 12, which preferably has at least 256 bytes.
• An advantageous energy and data transmission between the writing and reading station WR and the identification medium IM can be achieved by pulse modulation (pulse-pause modulation) by the writing and Reading station WR to the identification medium IM and by load modulation in the opposite direction from IM to WR.
• identification media with access and authorization functions are known for different systems and applications or for different applications, e.g. as access cards for certain areas of a company (electronic keys), for time management, as access media for devices, e.g. of data systems, or as prepaid card systems for purchasing services.
• the identification media according to the invention with significantly higher transmission powers and capabilities are therefore particularly suitable for applications with high requirements with regard to functional and data security, monitorability, prevention of misuse, etc.
• coded communication between the identification medium IM and the read / write station WR is used, e.g. by the writing and reading station generating new initialization data with each identification process and sending them to the identification medium IM, which are linked there with a permanently stored encryption code 32 (in FIG. 3) and sent back in coded form to the writing and reading station, where this information is decrypted and checked and then there is a synchronized communication between WR and IM.
• the identification medium can also be combined with a personal coding function in order to meet particularly high security requirements.
• a PIN code or biometric data codes can be used for this.
• Personal biometric data are determined, for example, from fingerprints or finger, hand and head geometry and compared with the corresponding codes 33 (FIG. 3) stored in the data carrier MI for the purpose of personal identification and verification of an authorized carrier.
• Another very important application which is only possible with identification media with a high level of communication capability, consists in a higher data organization of the memory 12 of the data carrier MI, wherein several independent applications can be written into a segmentable application data field ADF. Thanks to the higher communication performance of the identification medium according to the invention, a multiplication of its functions is achieved.
• FIG. 4 shows a further example of an identification medium with a receiving antenna, which is designed as a double antenna with two loops 15.1 and 15.2.
• the first antenna loop 15.1 serves to receive the electromagnetic field energy 20a for feeding the data carrier and to receive the data 20b of the writing and reading station WR.
• the second antenna loop 15.2 is used to send data 20b to the write and read station WR.
• the antenna parts 15.1 and 15.2 correspond to the inner capacitances Cil and Ci2 of the data carrier MI.
• FIGS. 8a and b show, as a particularly frequently used size, an identification medium in ISO card format 28 (85 ⁇ 54 mm) with conductor tracks 26 on a circuit board, which serve here as transmitting antenna 15.
• the antenna loops can be integrated with the external capacitance Ce and with the data carrier MI on a carrier 29 (inlet) and thus form a unit which can be produced particularly efficiently.
• external capacity Ce can For example, a ceramic capacitor in a very flat design, for example only 0.3 to 0.5 mm thick and with high quality in the MHz frequency range can be used.
• FIGS. 9 and 10 show examples of identification media with a small format (30), the diameter DA of the receiving antenna 15 should use the available space as completely as possible, so that the antenna area FA corresponds almost to the total area of the identification medium.
• identification media with antenna diameters of 30 mm and less, e.g. even of only 10 mm, it is particularly difficult to achieve good communication properties and long ranges.
• small identification media such as keys, key fobs, tokens etc., the same communication ranges can be achieved as with previous relatively large ISO format cards. This enables completely new applications to be opened up.
• FIG. 9 shows an example in which the receiving antenna is designed as a ferrite antenna 19 with a rod-shaped ferrite and an electrical winding.
• the identification medium is worn on a bracelet 36.
• the small format identification medium of Figure 10 represents a tag
• this identification medium could also be combined with a key, for example on the key handle, or be assigned to a carrier in another form.
• An example of a very small Identification media form eg rings, which can be attached to the foot of racing pigeons for the purpose of identifying the pigeons during races.
• a particularly advantageous development of the invention consists in also stabilizing the carrier frequency fr on the transmitter side in an analog manner, i.e. to make the transmitting antenna 24 of the writing and reading station WR more independent of external capacitive influences.
• the carrier frequency fr itself is already much more stable than the natural frequency f of the identification medium, further stabilization of the carrier frequency for the communication properties KL in the same sense as for the identification medium can significantly improve the range R in particular.
• the carrier frequency fr is also subject to the same influences as already explained: due to capacitive changes in the environment, e.g. by approaching the human body and metallic elements, by manufacturing tolerances and aging of components etc.
• the exact setting of a desired target value for the carrier frequency fr has hitherto required a complex coordination.
• This stabilization and improvement is achieved by applying the same principle as in the receiving antenna 15 to the transmitting antenna 24.
• an additional capacity Cz switched on parallel to the transmitting antenna and its inductance reduced accordingly, so that the product L. C of the transmitting antenna 24 remains constant.
• the additional capacity Cz is preferably chosen to be larger than the existing replacement capacity of the writing and reading station WR based on the base point of the transmitting antenna (ie without additional capacity).
• the additional capacity can advantageously be two to five times as large as the existing replacement capacity.
• This additional capacity Cz consists of a standard component with selectable, precisely defined and constant C values. In this way, a desired target value for the carrier frequency fr can be produced in a simple manner, without complex individual adjustments.
• a particularly advantageous and universally applicable transmission antenna 24 can be designed as a film antenna, e.g. as an antenna loop in the form of a wide conductor track on a plastic carrier (analogous to the much smaller antenna 15 in the example from FIG. 8).
• ranges of up to 1 m and more can be achieved with just one conductor track loop with a diameter of 60 cm and a track width of 25 mm (in a suitable shape: round, oval, rectangular, etc.), enabling ranges R to 1 m and more.
• any desired carrier frequency fr can be set directly - without the need for time-consuming experimentation and tuning.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Artificial Intelligence (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Computer Networks & Wireless Communication (AREA)
• Near-Field Transmission Systems (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=4189665

Family Applications (1)

Country Status (10)

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• 1998
  • 1998-02-19 ZA ZA981382A patent/ZA981382B/xx unknown
  • 1998-02-20 JP JP10539016A patent/JP2000509869A/ja active Pending
  • 1998-02-20 EP EP98902919A patent/EP0898763A1/de not_active Withdrawn
  • 1998-02-20 AU AU59794/98A patent/AU741616B2/en not_active Ceased
  • 1998-02-20 BR BR9805934-3A patent/BR9805934A/pt not_active Application Discontinuation
  • 1998-02-20 WO PCT/CH1998/000068 patent/WO1998040846A1/de not_active Application Discontinuation
  • 1998-02-20 CN CN98800608A patent/CN1226984A/zh active Pending
  • 1998-02-20 KR KR1019980708991A patent/KR20000010848A/ko not_active Application Discontinuation
  • 1998-02-20 CA CA002252411A patent/CA2252411A1/en not_active Abandoned
  • 1998-03-06 AR ARP980101005A patent/AR011183A1/es unknown

Non-Patent Citations (1)

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