This application is a national phase entry under 35 U.S.C. § 371 of International Patent Application PCT/FR2018/050956, filed Apr. 16, 2018, designating the United States of America and published as International Patent Publication WO 2018/193199 A1 on Oct. 25, 2018, which claims the benefit under Article 8 of the Patent Cooperation Treaty to French Patent Application Serial No. 1753405, filed Apr. 19, 2017.
The present disclosure relates to a radio frequency reception transmission device.
Documents U.S. Pat. No. 8,471,773 and FR2917895 are known as examples of such a device that can be used in the field of RFID (for “Radio Frequency Identification”) electronic labelling. The device includes a chip and a coupling device, often referred to as an “antenna,” for coupling of the chip to an electromagnetic field allowing communication with a transmission-reception terminal. The first document mentioned above states that, depending on the transmission frequency used between the transmission-reception terminal and the radio frequency device, the antenna of this device is configured to form either a loop (for transmission frequencies between a few hundred kilohertz and a few megahertz) or configured to form a dipole (for transmission frequencies between a few megahertz and a few gigahertz).
In the first type of RF device, with a relatively low frequency operating range, communication between the terminal and the RF device is only possible at a very short distance. A signal is induced in the coupling device without it actually forming an antenna (although it is customary to refer to this coupling device as an “antenna”). The coupling device can take the form of a loop. In this case, in reception mode, the signal can be developed by magnetic coupling. In other configurations of the RF device, the coupling device takes the form of a simple transmission line and the signal develops by electrical coupling with a transmission line of the transmitter, placed nearby. Whatever the form, electrical or magnetic, of the coupling between the transmitter and antenna, the transmitting-receiving chip is configured to operate “in the near field.” The transmitting-receiving chip includes a modulation circuit, a demodulation circuit and a power supply circuit, associated with the antenna and configured to make the transmission-reception chip active in the relatively low frequency operating range.
The second type of RF device, with a higher frequency operating range, is generally used for logistics applications, to identify, count, and/or track objects. The coupling device comprises a dipole antenna whose length is adjusted to the transmission frequency of the transmission-reception terminal and resonates with the generated electromagnetic field. This configuration makes it possible to establish, depending on the sensitivity of the chip and the terminal, a communication between the chip and the terminal when they are several meters apart, up to 10 m or 20 m. Such a “far-field” transmission-reception chip includes a modulation circuit, a demodulation circuit and a power supply circuit, associated with the dipole antenna and configured to make the transmission-reception chip active in the relatively high frequency operating range.
Whether the transmission-reception chip is configured to operate in the near or far field, it generally has an essentially capacitive internal impedance in the picofarad range. This is particularly the case for so-called “passive” transmission-reception chips, which draw their energies from the field received by the antenna.
For example, from documents US2012/258660 and U.S. Pat. No. 9,166,276, transmission-reception chips are known to operate in both near and far fields. The transmission-reception devices formed from these chips therefore remain relatively cumbersome and have a form factor that does not allow them to be integrated into all kinds of objects.
The present disclosure is intended to compensate for all or part of the above-mentioned disadvantages. In particular, this disclosure aims to provide a transmission-reception device capable of operating in both near and far fields, which has a more favorable form factor than state-of-the-art solutions.
To achieve the aim of the present disclosure, a radiofrequency transmission-reception device is disclosed herein that comprises:
According to the present disclosure, the first and second wire elements combine with the characteristic impedance of the second transmission-reception chip to form a coupling device associated with the first transmission-reception chip in the first frequency range. They also combine with the characteristic impedance of the first transmission-reception chip to form a coupling device associated with the second transmission-reception chip in the second frequency range.
According to other advantageous and limiting characteristics of the present disclosure, taken alone or in any technically feasible combination:
Other characteristics and advantages of the present disclosure will emerge from the detailed description of the present disclosure that follows with reference to the appended figures wherein:
To ensure the simplicity of the following description, the same references will be used for elements that are identical or perform the same function in the various disclosed embodiments of the process.
The present disclosure proposes a radiofrequency transmission-reception device comprising an antenna made up of two wire elements, and transmission-reception chips each comprising two longitudinal connection areas, parallel to each other and to which two segments of the wire elements are respectively fixed.
The present disclosure may use the connection technology referred to in the art as E-THREAD™. This technology is described, for example, in documents U.S. Pat. Nos. 8,093,617, 8,723,312, US2015318409, U.S. Pat. Nos. 8,782,880, 8,814,054 or US2015230336. However, in the following paragraphs, and in order to provide a complete description, the main characteristics of this technology are described herein.
Chip 1 has two longitudinal grooves 2a, 2b, forming the two longitudinal connection areas, each of these grooves being defined by three walls 3a, 3b, 3c of the elements constituting chip 1, in the example shown. In this disclosure, “longitudinal groove” (or “longitudinal area”) refers to a groove or area extending from one side of chip 1 to the other in a direction that arbitrarily defines the length of chip 1. Each groove 2a, 2b is designed to accommodate a segment of a wire element 4a, 4b. Each wire element 4a, 4b has a main axis, parallel to the axis of the longitudinal groove 2a, 2b in which it is located.
Each wire element 4a, 4b can be mechanically embedded in one of the longitudinal grooves 2a, 2b and/or held by an adhesive, by welding or by any other means in this groove. In all cases, the wire elements 4a, 4b and the chip are assembled together in a fixed manner.
As shown in
When it is necessary to form an electrical contact between a wire element 4a, 4b and a connection stud 8, it may be necessary to strip the conductive wire element 4a, 4b beforehand, if it is provided with an insulating sheath.
Alternatively or in addition, the connection stud 8 can have a sharp blade shape that pierces the sheath when the wire is inserted to establish electrical contact.
Further, in the description of
Other embodiments of chip 1 than the one shown in
In a particular embodiment, chip 1 does not have any groove. Cover 7 can only be temporarily connected to substrate 5 to temporarily form grooves and allow the wire elements 4a, 4b to be precisely fixed to substrate 5 in two parallel longitudinal connection areas. After this fixing step, cover 7 can be disassembled, and chip 1 in this case does not include cover 7.
A variant of this embodiment is described in document US2015024589 in which cover 7 is formed by applying an electrically insulating material to substrate 5 after fixing the wire elements 4a, 4b, for example, at two longitudinal connection areas 2a, 2b parallel to each other.
According to another embodiment, the chip 1 can consist of two flat supports of identical or similar dimensions, each having a functional circuit. The flat supports are each assembled to the two opposite sides of a smaller spacer to define the two longitudinal grooves 2a, 2b of the chip 1.
Whatever the embodiment chosen, a chip 1 compatible with the present disclosure has a functional circuit 6, two longitudinal connection areas 2a, 2b each capable of receiving a segment of a conductive wire element 4a, 4b. The conductive wire elements 4a, 4b are in electrical contact with the functional circuit 6.
The fixing of the conductive wire elements 4a, 4b on the longitudinal areas 2a, 2b of a chip 1 can be automated, for example, using insertion equipment such as that described in document U.S. Pat. No. 8,782,880 or US2015024589.
Large wire elements can be supplied in the equipment in the form of coils; and chips 1, similar to the one just presented, stored in a tank of the equipment. Large wire elements are unwound from the coils to be supplied, parallel to each other, to a pinching zone of the piece of equipment. The equipment is also configured to successively bring chips 1 from the tank to this pinching zone and to engage a segment of each large wire element in either of the longitudinal grooves 2a, 2b, or more generally to attach each wire element 4a, 4b to the longitudinal connection areas 2a, 2b. A chain is thus formed, which consists of a plurality of chips 1 connected by large wire elements. The equipment can be provided with a plurality of tanks to store chips of different natures and form a chain of composite chips according to an alternation, which may be chosen. The chip chain can be wound on a support to form a storage or transport reel. Functional elements, i.e., sections of this chain, can be removed from the reel by cutting the wire elements 4a, 4b according to a desired cutting pattern, as described in the above-mentioned document U.S. Pat. No. 8,471,773.
The present disclosure takes advantage of the general characteristics of the technology presented above to offer a radiofrequency transmission-reception device 10 that can operate in both far and near fields.
Such a device 10 is shown in
The first chip 21 has two longitudinal connection areas to which two longitudinal segments 4a1, 4b1 of the wire elements 4a, 4b are respectively fixed. The areas are equipped with connection studs to connect each wire element 4a, 4b to the functional circuit 6 of the first far field chip 21.
The first chip 21 has a first characteristic impedance between its connection studs. This characteristic impedance may depend on frequency, but usually it is capacitive in nature and typically has a value of a few picofarads.
To further the description in
Similar to the first chip 21, the second chip 22 has two longitudinal connection areas to which the two wire elements 4a, 4b are respectively fixed, at longitudinal segments 4a2, 4b2. The areas of the second chip 22 are equipped with connection studs that connect each wire element to the functional device of this second chip 22. It also has, between its studs, a second characteristic impedance that can depend on frequency and is also usually capacitive in nature, of a few picofarads.
In the configuration shown in
In this state, the first transmission-reception chip 21 is likely to work, i.e., if a coupling device, such as a dipole antenna, is electrically connected to its connection terminals, the first chip 21 is able to demodulate the supplied signal, perform processing and, in return, modulate information to be transmitted via the coupling device.
The second chip 22 is not likely to work at this frequency. That is to say, its behavior is purely passive and, given its connection terminals, it constitutes a pure impedance whose value corresponds to its characteristic impedance at this frequency.
In this state, and in contrast to what has been presented in relation to
The present disclosure uses these observations to ensure that, in the first frequency range, the first wire element 4a and the second wire element 4b electrically combine with the characteristic impedance of the second transmission-reception chip 22 to form a coupling device associated with the first transmission-reception chip 21.
In other words, the second chip 22, which is passive in the first frequency range, electrically combines with the wire elements 4a, 4b to form the antenna connected to the first chip 21 allowing the transmission-reception device 10 to be fully functional in this first frequency range.
In the second frequency range, the first and second wire element 4a, 4b electrically combine with the characteristic impedance of the first chip 21 to form a coupling device associated with the second chip 22. In other words, the first chip 21, which is passive in the second frequency range, electrically combines with the wire elements 4a, 4b to form the antenna connected to the second chip 22 allowing the transmission-reception device 10 to also be fully functional in this second frequency range.
In
These transmission lines constitute the coupling device of the second near-field chip 22, capable of transmitting and receiving a radiofrequency electrical signal to another transmission line 31 of a transmission-reception terminal 30 located near the device 10. Preferably, to improve the quality of the transmission, the terminal's transmission line 31 is arranged parallel to the transmission line consisting of one of the wire elements 4a, 4b. It will also be possible to easily adapt the impedance of the coupling device in the form of transmission lines, by adjusting the length of the wire elements and/or adjusting the distance between these two wire elements, i.e., the distance between the connection areas to which the wire elements are fixed from the first and second transmission-reception chips 21, 22.
In
At this operating frequency, the second chip 22 is passive and its characteristic impedance being of a capacitive nature, it constitutes at this frequency a short circuit.
In this configuration, the two wire elements 4a, 4b electrically connected to the connection terminals of the first far-field chip 21 form a dipole antenna. For this purpose, the length of each wire element is chosen to correspond to a quarter of the length of the propagating wave, as is well known in itself. The short circuit of the second near field chip 22 at the operating frequency of the first chip provides a loop for matching the antenna impedance. This effect can be used to choose the distance between first and second chips 21 and 22 so that this loop actually has the required size to allow this adaptation.
The coupling device thus constituted in dipole is able to transmit and receive a radiofrequency electromagnetic signal at the operating frequency of the first chip. It can communicate with a transmission-reception terminal 30 equipped with a compatible antenna 31. This transmission can be carried out at a long distance, up to several meters, between the transmission-reception device 10 and terminal 30.
It should therefore be noted that at the operating frequency of the second chip 22, the wire elements 4a, 4b combine with the characteristic impedance of the first chip and the inductive element 25 to form a loop coupling device. The arrangement of this coupling device is capable of transmitting and receiving, by magnetic induction, a radiofrequency magnetic signal at the operating frequency of the second chip 22 and communicating with a transmission-reception terminal 30 equipped with its own coupling device 31.
Advantageously, and as shown in
In a variant of this particularly advantageous second embodiment, the inductive element 25 is integrated into the first chip 21. This avoids the need to attach inductive element 25 separately between wire elements 4a and 4b. This variant can be implemented using a first chip 21, which integrates the inductive device 25 into a cover 7, for example, as shown in
In order to promote electromagnetic coupling, the space between the two chips 21, 22 and forming at least part of the coupling device may be filled with a ferromagnetic material.
Whatever the embodiment chosen and the variants used, the transmission-reception device 10 according to the present disclosure has the characteristic of being able to operate in both near and far fields. The device 10 uses components, including first and second standard transmission-reception chips 21, 22, and is therefore available at low cost. It has a very advantageous form factor, and is not significantly more cumbersome than a transmission-reception device operating only in one of the near or far field transmission-reception modes.
Of course, the present disclosure is not limited to the described embodiments and alternative solutions can be used without departing from the scope of the present disclosure as defined in the claims.
Thus, although transmission-reception chips with a capacitive impedance have been chosen here in the different embodiments described, it is possible to consider implementing the present disclosure with transmission-reception chips with an impedance of a different nature. It will be easy to adapt to this situation by planning to place adaptation components between the two wire elements, similar to the inductive component 25, in order to obtain the equivalent electrical diagrams required in high and low frequency. It will also be possible, as is well known to the skilled person, to adjust the length, spacing and termination of the wire elements to adapt the impedance of the coupling device to the nature of the characteristic impedance of the first chip 21 and/or the second chip 22.
In addition, it is not necessary for both functionalities “in the near field” and “in the far field” of the transmission-reception device to be used. Consideration may be given to providing generic devices according to the present disclosure for which a user could use only one of both functionalities.
Number | Date | Country | Kind |
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1753405 | Apr 2017 | FR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/FR2018/050956 | 4/16/2018 | WO |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2018/193199 | 10/25/2018 | WO | A |
Number | Name | Date | Kind |
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8093617 | Vicard et al. | Jan 2012 | B2 |
8471773 | Vicard | Jun 2013 | B2 |
8723312 | Brun et al. | May 2014 | B2 |
8782880 | Vicard et al. | Jul 2014 | B2 |
8814054 | Brun et al. | Aug 2014 | B2 |
20090073070 | Rofougaran | Mar 2009 | A1 |
20110068987 | Carr | Mar 2011 | A1 |
20120258660 | Rajendran et al. | Oct 2012 | A1 |
20140117927 | Chateau et al. | May 2014 | A1 |
20150024589 | Brun | Jan 2015 | A1 |
20150230336 | Vicard et al. | Aug 2015 | A1 |
20150318409 | Vicard et al. | Nov 2015 | A1 |
Number | Date | Country |
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1630728 | Nov 2007 | EP |
3319168 | May 2018 | EP |
2917895 | Apr 2010 | FR |
2937464 | Feb 2011 | FR |
Entry |
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International Search Report for International Application No. PCT/FR2018/050956 dated Jul. 5, 2018, 3 pages. |
International Written Opinion for International Application No. PCT/FR2018/050956 dated Jul. 5, 2018, 6 pages. |
Number | Date | Country | |
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20200381829 A1 | Dec 2020 | US |