Tunable resonance frequency chip document.

Abstract

The invention relates to a tunable resonant frequency chip document (100), comprising: • a first antenna (110), for exchanging data with a card reader, and having a first resonant frequency. It is characterized in that it further comprises: • a second antenna (120), comprising a first set of turns (121) and at least one capacitive loop (122), and having: o a first value of a second resonant frequency when an electrical conductor is at a distance from the capacitive loop, this first value being greater than the first resonant frequency, o a second value of a second resonant frequency when an electrical conductor is near the capacitive loop, this second value being substantially equal to the first resonant frequency.

Description

Title of the invention: Tunable resonant frequency chip document.

[0001] The present invention relates to the field of chip documents, in particular those with tunable resonant frequency.

[0002] A smart card includes a resonant electronic circuit that has a resonant frequency. This resonant frequency can be standardized, for example for exchanges between the card and a reader in the identity domain, including for secure access, or banking.

[0003] There are electronic circuits that resonate at two resonant frequencies. For example, document CA3009493 describes a ticket reader comprising an antenna that includes a first loop tuned to a first frequency and a second loop tuned to a second frequency, which allows interaction with several transport cards.

[0004] The present invention, however, relates to a resonant circuit with a tunable resonant frequency, for a use very different from that of the prior art cited above.

[0005] Indeed, more and more applications for communication between a smart document and a smartphone are emerging. Many uses are now proposed, in the banking sector for payments, or in the identity sector for authenticating, identifying oneself or signing documents via a smartphone and an identity card.

[0006] In these areas, it is common to at least go through an enrollment phase, which involves biometrics. The biometrics market is developing, but a current obstacle to this deployment is the need for user fingerprint enrollment, particularly due to the time required for this biometric enrollment step, typically several tens of seconds.

[0007] A known solution at this stage is to perform this enrollment step using a cradle, which is a support that allows the smart document to be correctly positioned relative to the smartphone's NFC antenna. The cradle may incorporate an antenna to improve communication between the smart document and the smartphone.

[0008] However, this solution is not optimal and interoperability problems still exist between a chip-enabled document and a smartphone, for example for at least one of the following reasons: - due to the small size of the smartphone antenna compared to the antennas of payment terminals or desktop readers; - due to the presence of a battery and the metallic environment proximity of the antenna in the smartphone which can disrupt electromagnetic waves; - due to the power available in a smartphone, which can be relatively low; - due to the different positioning of the NFC antenna in each smartphone, which means that the same cradle will have different effects depending on the smartphone; - etc.

[0009] However, there is a need for precise relative positioning of the chip document and the smartphone, more specifically of their respective antennas, so that the coupling between the radio frequency circuits is optimal in order to avoid reading or enrollment errors.

[0010] In this context, according to one of its objects, the present invention relates to a chip-enabled document (100) with a tunable resonant frequency, comprising:

[0011] • a card body (101),

[0012] • an external face,

[0013] • a module (140), comprising a secure element,

[0014] • a first antenna (110), configured to be able to perform a transfer of data and energy between the module (140) and a card reader when the smart document (100) is in the field of said reader and exhibiting a first resonant frequency.

[0015] It is essentially characterized in that it further comprises:

[0016] • a second antenna (120), comprising:

[0017] o a first set of turns (121),

[0018] or a first set of at least one capacitive loop (122), connected with the first set of turns (121),

[0019] • such that the second antenna (120) has:

[0020] o a first value of a second resonance frequency when the chipped document (100) is in the field of said reader and an electrical conductor is at a distance greater than a threshold value of the capacitive loop, the first value of the second resonance frequency being greater than the first resonance frequency,

[0021] or a second value of a second resonance frequency when the chipped document (100) is in the field of said reader and an electrical conductor is at a distance less than a threshold value of the capacitive loop, the second value of the second resonance frequency being substantially equal to the first resonance frequency.

[0022] It can be foreseen that the second antenna (120) further comprises at least one among :

[0023] • a second set of turns (123),

[0024] • a second set of at least one capacitive loop (124), connected with the first set of turns (121) or with the second set of turns (123).

[0025] A concentrator (130), connected to the first antenna (110), can also be provided.

[0026] It can be predicted that:

[0027] • The first antenna (110) and the second antenna (120) are arranged on a respective support; or

[0028] • The first antenna (110) and the second antenna (120) are arranged on a the same support comprising two opposite faces, such as:

[0029] i. The first antenna (110) and the second antenna (120) are arranged on the same face of the support,

[0030] ii. The first antenna (110) and the second antenna (120) are arranged on a respective face of the support,

[0031] iii. at least one of the first antenna (110) and the second antenna (120) is arranged on either side of the support.

[0032] It can be foreseen that the second antenna (120) is configured so that, when the chipped document (100) is in the field of said reader and an electrical conductor is at a distance less than a threshold value of the capacitive loop, the coupling between said reader and said chipped document (100) is optimal.

[0033] A biometric module (160) can also be provided, in galvanic or electromagnetic connection with the module (140).

[0034] It can be predicted that the shape of the first set of at least one capacitive loop (122) locally follows the shape of the second set of at least one capacitive loop (124).

[0035] It can be predicted that the shape of the first set of at least one capacitive loop (122) and the shape of the second set of at least one capacitive loop (124) locally form a set of at least one ripple.

[0036] A marking element can also be provided disposed at the right of at least one of the first set of at least one capacitive loop (122), and the second set of at least one capacitive loop (124), to mark the position of said set of at least one capacitive loop.

[0037] According to another of its objects, the invention also relates to a system comprising a smart document (100) according to the invention, and a card reader in the form of a smartphone (200).

[0038] Other features and advantages of the present invention will become more apparent upon reading the following description given by way of illustrative example and non-exhaustive and made with reference to the attached figures.

[0039] The figures are not necessarily to scale. Some details may have been omitted or others amplified to facilitate understanding. Figures

[0040] [Fig-1] illustrates an embodiment of a chip-enabled document according to the invention,

[0041] [Fig.2] illustrates another embodiment of a chip-enabled document according to the invention,

[0042] [Fig.3] illustrates biometric enrollment with an embodiment of chip-enabled document according to the invention,

[0043] [Fig.4] illustrates another embodiment of the shape of a first loop ca peaceful and a second capacitive loop according to the invention. Detailed description

[0044] Figure 1 illustrates an embodiment of a smart document 100 according to the invention. In this case, the smart document 100 is a smart card. Not shown, and not exhaustively, the smart document 100 could also be a passport or an identity card.

[0045] When the chip document 100 is a chip card, it can be implemented for banking, security or identity applications.

[0046] It comprises a card body 101 and an outer face (not referenced in the figures).

[0047] In a conventional manner, it also includes a module 140, which includes a secure element.

[0048] Finally, it also conventionally includes a first antenna 110.

[0049] The first antenna 110 is for example known under the terminology “ID-1” in reference to the ISO / IEC 7810 standard in the field of smart cards.

[0050] The first antenna 110 is configured to be able to perform a data and energy transfer between the module 140 and a card reader when the smart document 100 is in the field of said reader.

[0051] The reader is for example an ad hoc device such as a terminal, for example a payment terminal when the chip document 100 is a bank card, or a smartphone-type device 200.

[0052] The first antenna 110 is configured to be able to present a first resonant frequency. For example, the first resonant frequency is standardized, for example, to 13.56 MHz.

[0053] According to the invention, the chip document 100 further comprises a second antenna 120.

[0054] The second antenna 120 comprises a first set of turns 121. For example, the turns of the first set of turns 121 are concentric with respect to to module 140.

[0055] The second antenna 120 comprises a first set of at least one capacitive loop 122, connected with the first set of turns 121, such that the first set of at least one capacitive loop 122 can influence the resonant frequency of the second antenna 120 in the following manner. Those skilled in the art will understand that the antenna technology can be wire (copper), etched, or additive (copper, aluminum, silver).

[0056] The second antenna 120 has two resonant frequencies, i.e. two values ​​of a second resonant frequency depending on the conditions of use, when the chip document 100 is in the field of view of the reader:

[0057] When an electrical conductor is at a distance greater than a threshold value from the first set of at least one capacitive loop 122, then the second antenna 120 has a first value of the second resonant frequency, greater than the first resonant frequency.

[0058] Preferably, the first value of the second resonant frequency is provided to be at least 3 MHz, and preferably at least 5 MHz higher than the first resonant frequency. For example, for a first resonant frequency of 13.56 MHz, the first value of the second resonant frequency is at least 16 MHz, and preferably greater than 20 MHz.

[0059] Thus in use by a standard reader, when an electrical conductor is at a distance from the first set of at least one capacitive loop 122, that is to say at a distance greater than a threshold value, then the chip document 100 resonates at the frequency of the first resonance frequency, and the presence of the second antenna 120 is transparent to the operation of the chip document 100.

[0060] On the other hand, when an electrical conductor is at a distance less than a threshold value from the first set of at least one capacitive loop 122, then the second antenna 120 has a second value of the second resonance frequency, the second value of the second resonance frequency being substantially equal to the first resonance frequency.

[0061] By "approximately equal", it is meant that the second value of the second resonance frequency is equal to the first resonance frequency plus or minus 20%.

[0062] For example the electrical conductor is a piece of metal, or a finger of the user, in particular placed on the chip-enabled document 100, as illustrated in [Fig.3].

[0063] Preferably, to obtain the second value of the second resonant frequency, the electrical conductor is as close as possible to the first set of at least one capacitive loop 122, and in particular in contact with the card body 101 of the chip-enabled document 100, as illustrated in [Fig.3].

[0064] Thus in use by a standard reader, when an electrical conductor is in the vicinity of the first set of at least one capacitive loop 122, that is to say at a distance less than a threshold value, then the second antenna 120 resonates at the second value of the second resonant frequency.

[0065] In this case, when the chip document 100 is in the field of the reader and an electrical conductor is at a distance less than a threshold value of the capacitive loop, then the second antenna 120 resonates at the second value of the second resonance frequency, which allows optimal coupling between the reader and the chip document 100, the second antenna 120 acting as an electromagnetic waveguide allowing the waves from the reader to be concentrated towards the first antenna 110 in the case of a galvanically connected chip or towards the module 140 in the case of an inductively coupled chip.

[0066] Preferably, the second antenna 120 is provided to further comprise at least one of the following:

[0067] • a second set of turns 123,

[0068] • a second set of at least one capacitive loop 124, connected with the first set of turns 121 or with the second set of turns 123.

[0069] For brevity, "first set of at least one capacitive loop 122" and "first capacitive loop 122" are understood interchangeably, as well as "second set of at least one capacitive loop 124" and "second capacitive loop 124".

[0070] The first capacitive loop 122 and the second capacitive loop 124 form a capacitive connection pad. The presence or absence of an electrical conductor near or in contact with this connection pad determines the capacitance of the electrical circuit, which amounts to selectively activating the first value of the second resonant frequency or the second value of the second resonant frequency.

[0071] Preferably, the shape of the first set of at least one capacitive loop 122 locally matches the shape of the second set of at least one capacitive loop 124, as illustrated in [Fig.1] and [Fig.2].

[0072] In a non-limiting example, the shape of the first set of at least one capacitive loop 122 and the shape of the second set of at least one capacitive loop 124 locally form a set of at least one ripple, as illustrated in [Fig.1] and [Fig.2].

[0073] It can also be predicted that the shape of the first set of at least one capacitive loop 122 and the shape of the second set of at least one capacitive loop 124 locally form a set of stair steps, as illustrated in [Fig.4].

[0074] the shape of the first set of at least one capacitive loop 122 locally conforms to the shape of the second set of at least one capacitive loop 124.

[0075] Advantageously, the shape and arrangement of the first set of at least one capacitive loop 122 and the shape and arrangement of the second set of at least one capacitive loop 124 are such that when an adult finger is placed on the first set of at least one capacitive loop 122, then the finger also at least partially covers the second set of at least one capacitive loop 124, so as to present a desensitization to the position of the finger.

[0076] To this end, it may be provided that the card body 101 includes a marking element 170, as illustrated in [Fig.3], disposed in front of at least one of the first set of at least one capacitive loop 122 and the second set of at least one capacitive loop 124, to mark the position of said set of at least one capacitive loop.

[0077] The marking element 170 is a graphic representation which is presented for example in the form of a self-adhesive label or a marking directly on the surface of the card, for example by embossing, engraving, painting, etc.

[0078] For example, not illustrated, the marking element 170 has an oval shape or a fingerprint, so as to facilitate the positioning of the user's finger on the face of the chip document 100 during biometric enrollment.

[0079] Furthermore, it can be foreseen that the second set of turns 123 is concentric with respect to the module 140, as illustrated for example in [Fig. 1]. More generally, it can be foreseen that at least one of the first set of turns 121 and the second set of turns 123 is concentric around the module 140, in particular if the module 140 itself includes an antenna.

[0080] It can be foreseen that the chip document 100 further includes a concentrator 130, connected to the first antenna 110. The concentrator 130 optimizes the coupling between the module 140 and the first antenna 110. Generally the module 140 includes an antenna (not illustrated) and the concentrator 130 is preferably concentric with the antenna of the module 140.

[0081] According to the invention, the coupling between the module 140 and the first antenna 110 can be either galvanic or inductive.

[0082] It can be foreseen that the chip-enabled document 100 includes a set of at least one antenna support.

[0083] In a first variant, the first antenna 110 and the second antenna 120 are arranged on a respective support.

[0084] In a second variant, the first antenna 110 and the second antenna 120 are arranged on the same support, the support comprising two opposite faces.

[0085] In this case, the first antenna 110 and the second antenna 120 can be arranged: - on the same side of the support, or - a respective face of the support.

[0086] It can also be provided that at least one of the first antenna 110 and the second antenna 120 is arranged on either side of the support.

[0087] According to a non-limiting variant, it can be provided that the chip-bearing document 100 includes an antenna support on which the second antenna 120 is arranged and that: - the first set of turns 121 and the first set of at least one capacitive loop 122 are arranged on one face of the support, - the second set of turns 123 and the second set of at least one capacitive loop 124 are arranged on the other face of the support, - the thickness of the first set of turns 121 and of the first set of at least one capacitive loop 122 may be different from the thickness of the second set of turns 123 and of the second set of at least one capacitive loop 124; - the first set of turns 121 and the second set of turns 123 being electrically connected by an electrical linking device 150.

[0088] Depending on the antenna technology implemented, the electrical link device 150 is a via (or crimp) or a bridge (or jump).

[0089] In one embodiment, the chip document 100 further comprises a biometric module 160, as illustrated in [Fig. 1]. The biometric module 160 is in galvanic or electromagnetic connection with the module 140. By "electromagnetic connection" is meant any one of the following connections (or couplings): an electrical connection, a capacitive connection, an optical connection, and an inductive connection.

[0090] For biometric enrollment, illustrated in [Fig. 3], the user can act from the in the following way:

[0091] He places his chip document 100 on a stable support and then his smartphone 200, reader server, on the chip document 100.

[0092] The user then places a finger to be enrolled on the biometric module (or sensor) 160 and another finger on at least one of the first set of at least one capacitive loop 122 and the second set of at least one capacitive loop 124.

[0093] Since the finger is an electrical conductor, the second antenna 120 then presents the second value of a second resonant frequency and acts as a waveguide between the smartphone 200 and the module 140 of the chip document 100, which promotes enrollment through optimal coupling between the smartphone 200 and the module 140 of the chip document 100. The coupling can be between the second antenna 120 and the antenna of the module 140 (for modules 140 with inductive connection), or between the second antenna 120 and the first antenna 110 (for modules 140 with galvanic connection).

[0094] By removing the user's finger from the second antenna 120, the chip document 100 returns to its first resonant frequency and can be used conventionally for banking, security or identity purposes.

[0095] Thanks to the present invention, the coupling between a reader and the chip-enabled document is optimal, thanks to a second antenna 120 which allows frequency tuning and is advantageously integrated into said document. Thus, it is not necessary to use a support / template / label, etc., which would integrate such a second antenna.

[0096] The second antenna 120 is not necessarily physically accessible from outside the chip document 100.

[0097] In particular when the smart document 100 is a smart card 100, it can be provided that the second antenna 120, in particular at least one of the first set of turns 121 and the second set of turns is physically accessible from outside the smart card 100, in this case through the edge thereof.

[0098] The present invention promotes interoperability between a reader (smartphone) and a chip document 100, by temporarily increasing the performance of the radio frequency circuit of the chip document 100.

[0099] Nomenclature

[0100] 100 Chip-enabled document

[0101] 101 map body

[0102] 110 first antenna

[0103] 120 second antenna

[0104] 121 first set of turns

[0105] 122 first capacitive loop

[0106] 123 second set of turns

[0107] 124 second capacitive loop

[0108] 130 concentrator

[0109] 140 module

[0110] 150 electrical connection device [YES] 160 biometric module

[0112] 170 marking element

[0113] 200 smartphone

Claims

Claims

1. Smart document (100) with tunable resonant frequency, comprising: • a card body (101), • an external face, • a module (140), comprising a secure element, • a first antenna (110), configured to be able to carry out a transfer of data and energy between the module and a card reader when the smart document (100) is in the field of said reader and having a first resonant frequency; characterized in that it further comprises • a second antenna (120), comprising: • a first set of turns (121), • a first set of at least one capacitor loop (122), connected with the first set of turns (121),• such that the second antenna (120) has: • a first value of a second resonant frequency when the smart document (100) is in the field of said reader and an electrical conductor is at a distance greater than a threshold value from the capacitive loop, the first value of the second resonant frequency being greater than the first resonant frequency, • a second value of a second resonant frequency when the smart document (100) is in the field of said reader and an electrical conductor is at a distance less than a threshold value from the capacitive loop, the second value of the second resonant frequency being substantially equal to the first resonant frequency.,

2. The smart document (100) of claim 1, wherein the second antenna (120) further comprises at least one of: • a second set of turns (123), • a second set of at least one capacitive loop (124), connected with the first set of turns (121) or with the second set of turns (123).

3. A smart document (100) according to any preceding claim, further comprising a hub (130), connected to the first antenna (110) and disposed around the module (140).

4. Smart document (100) according to any one of the preceding claims, wherein: • Either the first antenna (110) and the second antenna (120) are arranged on a respective support; • Either the first antenna (110) and the second antenna (120) are arranged on the same support comprising two opposite faces, such that: i. The first antenna (110) and the second antenna (120) are arranged on the same face of the support, ii. The first antenna (110) and the second antenna (120) are arranged on a respective face of the support, or iii. at least one of the first antenna (110) and the second antenna (120) is arranged on either side of the support.

5. A smart document (100) according to any preceding claim, wherein the second antenna (120) is configured such that, when the smart document (100) is in the field of said reader and an electrical conductor is at a distance less than a threshold value from the capacitive loop, the coupling between said reader and said smart document (100) is optimal.

6. A smart document (100) according to any preceding claim, further comprising a biometric module (160), in galvanic or electromagnetic connection with the module (140).

7. A smart document (100) according to any one of claims 2 to 6, wherein the shape of the first set of at least one capacitive loop (122) locally matches the shape of the second set of at least less one capacitive loop (124).

8. A smart document (100) according to claim 7, wherein the shape of the first set of at least one capacitive loop (122) and the shape of the second set of at least one capacitive loop (124) locally form a set of at least one ripple.

9. A smart document (100) according to any preceding claim, comprising a marking element disposed in line with at least one of the first set of at least one capacitive loop (122), and the second set of at least one capacitive loop (124), for marking the position of said set of at least one capacitive loop.

10. System comprising a smart document (100) according to any one of the preceding claims, and a card reader in the form of a smartphone (200).