RFID tag and manufacturing method

Abstract

The present disclosure relates to a radio frequency identification, RFID, tag. The RFID tag comprises a radio module comprising: an integrated circuit comprising RFID circuitry, an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element. Moreover, the RFID tag also comprises a conductive wire, which is configured to act as the antenna of the RFID tag. The conductive wire comprises a section supported by the package of the radio module. The present disclosure also relates to a method of manufacturing an RFID tag.

Description

RFID TAG AND MANUFACTURING METHOD

[0001] The present application claims the benefit of European patent application n° EP24171301.5 filed on April 19th, 2024. The present disclosure relates to radio frequency identification tags and to manufacturing methods for radio frequency identification tags.BACKGROUND

[0002] Radio frequency identification (RFID) tags are commonly used in various applications for enabling identification and management of items to which they are attached. In some applications, RFID tags may be attached to various textile items (e.g., clothes or linen) and / or fibers. This may enable, for example, tracking of textile items for the industrial, healthcare and hospitality sectors. In such applications, the RFID tags must be able to withstand repeated exposure to washing and / or other laundry processes causing significant physical stress on the RFID tag. Such RFID tags should also preferably be suitable for serial production.

[0003] Conventional RFID tags comprise an integrated circuit (IC) which is physically and electrically connected to an antenna for enabling reception of signals from free space and transmission of signals, via the antenna, to free space. In other words, a galvanic connection is provided between the IC and the antenna. Such electrical connection between the IC and the antenna is typically achieved via a conductive element (e.g., a conducting line, a transmission line or a cable), which may not be able to withstand the physical stress it is subjected to. Consequently, it may become detached and / or damaged.

[0004] In order to overcome this problem, solutions have been proposed wherein the IC of the RFID tag is no longer electrically connected to the antenna of the RFID tag via a wired connection. Instead, an inductive element is provided to enable a wireless connection. In some proposed designs, the IC of the RFID tag incorporates such inductive element, which provides inductive coupling (or magnetic coupling) with the antenna. An encapsulating element or package is used to encapsulate the IC which, in these designs, includes the inductive element.

[0005] Alternatively, in other proposed designs, a separate non-integrated inductive element is provided. In such cases, an encapsulating element or dedicated package isemployed to house both the IC and the inductive element. The IC may comprise its own IC package and this may contain an opening for at least one external lead for connecting the inductive element to the RFID circuitry. In this manner, a monolithic arrangement, which comprises both the IC and the inductive element, is also achieved.

[0006] Such monolithic arrangement provides enhanced protection of the RFID tag against harsh environments. In such proposed solutions, the antenna of the RFID tag is then inductively coupled to the inductive element, thus avoiding any physical or galvanic electrical connection. The antenna is typically implemented as a conductive wire or metal foil. As far as the package is concerned, a non-conductive material is commonly selected.

[0007] In the above-mentioned designs, the antenna of the RFID tag is attached to a substrate, e.g. a textile substrate. Subsequently, the IC incorporating the inductive element (or the package comprising both the IC and the inductive element) is also attached, e.g. sewn, glued, or inserted in a pouch, to the substrate. In order to provide inductive coupling between the antenna and the inductive element, the antenna and the IC or package containing the inductive element are arranged relatively close to each other. Furthermore, the antenna is arranged in the substrate with a shape that at least partially surrounds the inductive element contained in the IC or package. In some existing solutions, the antenna is arranged, e.g. embroidered, or sewn, on the substrate and it forms a loop around the package.

[0008] Solutions comprising an inductive element inductively coupled with the antenna of the RFID tag offer a more robust solution that conventional RFID tags comprising a galvanic connection with the antenna. Nevertheless, existing solutions still exhibit some limitations or problems.

[0009] In particular, the read range of RFID tags is limited to about one meter for low frequency (e.g. 125 Hz) and high frequency (e.g. 13.56 MHz), whereas a read range of RFID for Ultra High Frequencies (e.g. 860 - 960 MHz) may be 6 - 8 meters. In certain implementations it is desirable to increase the read range.

[0010] Multiple loops have been proposed in the antenna to try and increase the coupling with the inductive element. Nevertheless, with the antenna arranged on a substrate only the first loop can be arranged at the shortest distance from the IC whereas remaining additional loops are arranged at increasing distances. As an example, multiple loops may be arranged forming a spiral shape in a two-dimensional arrangement. The IC may be positioned substantially at the center of the spiral shape. Nevertheless, the consecutive loops will be arranged at increasing diameters, thus increasing the distance from the IC to the respectiveloop and, accordingly, decreasing the effectiveness of the inductive coupling. Furthermore, the addition of further loops may not significantly improve the inductive coupling and, consequently, may not significantly improve the performance of the RFID tag.

[0011] In examples of the present disclosure, improved RFID tags are provided which at least partially overcome some of the above-mentioned limitations. Furthermore, in examples of the present disclosure, manufacturing methods for RFID tags are also provided.

[0012] It should be emphasized that, while the examples of the present disclosure may be especially beneficial in view of the aforementioned textile-related applications, corresponding RFID tags and ICs may be used, in general, in any application area of RFID tags. The RFID tags and associated ICs according to the disclosure are especially well-suited for any applications where the RFID tags suffer from significant wear and tear or encounter significant physical stress or are exposed to strong external physical pushing, pulling and / or tearing forces and / or where large quantities of the RFID tags need to be produced quickly and efficiently in an automated manner.SUMMARY

[0013] In an aspect of the disclosure, a radio frequency identification, RFID, tag is provided. The RFID tag comprises a radio module comprising an integrated circuit comprising RFID circuitry. The radio module further comprises an inductive element to inductively couple the RFID circuitry to an antenna of the RFID tag. Furthermore, the radio module comprises a package configured to encapsulate, at least in part, the integrated circuit and the inductive element. The RFID tag further comprises a conductive wire, configured to act as the antenna of the RFID tag. The conductive wire comprises a section supported by the package of the radio module.

[0014] According to this aspect of the disclosure, an RFID tag with improved capabilities and performance is obtained. The disclosure overcomes the weak coupling found in previously proposed designs. The conductive wire, acting as the antenna of the RFID tag, is supported by the package of the RFID module itself, thus reducing the distance between the antenna and the inductive element arranged within the package. Such distance exhibits a clear effect on the efficiency of the inductive coupling. Consequently, by placing the conductive wire on the package itself, an optimum short distance between the different elements is achieved. In previously proposed designs, the antenna and the IC are provided onto a substrate, on which the antenna and the IC are fixedly attached to the substrate by a retention element, forexample, a thread for securing the antenna to the substrate and / or a pouch-type enclosure built in the substrate to receive the IC, such that the antenna and the IC remain at a fixed position relative to each other. Thus, inherent distances between the antenna and the IC are present in previously proposed designs due to the separate arrangement of the IC and the antenna on the substrate because of the retention element that further distances the antenna from the IC.

[0015] Furthermore, previously proposed designs required a substrate and comprised two- dimensional arrangements, i.e. the disposition of the different elements was constrained to a plane. Now, according to this aspect of the disclosure, the RFID tag is no longer confined to two dimensions and three-dimensional arrangements can be implemented. Consequently, the conductive wire can be supported around the package, containing the IC and the inductive element, in a more customizable form.

[0016] Throughout the present disclosure, the “package” may be regarded as any form of enclosure or encapsulation of semiconductor devices or integrated circuits. In examples, the package may be made of metal, plastic, glass, or ceramic casing.

[0017] In some examples, the radio module may comprise a magnetically permeable material. In particular, in some variants, the package of the radio module may comprise such a magnetically permeable material. In other variants, a core comprising a magnetically permeable material, e.g. a ferrite core, may be arranged within the package of the radio module.

[0018] These examples of the present disclosure take advantage of the physical principle that a magnetically permeable material exhibits a magnetic permeability which allows the magnetically permeable material to conduct or steer a magnetic flux field. Particularly, the magnetically permeable material may deform a magnetic flux component of the electromagnetic energy. The magnetic flux component, having been deformed, may concentrate flux lines through the magnetically permeable material. The flux lines, having been concentrated, may couple the electromagnetic energy to the antenna with an increased efficiency as compared to an RFID tag comprising a radio module without the magnetically permeable material. Furthermore, the magnetically permeable material may allow using a smaller integrated circuit and corresponding inductive element. Without the magnetically permeable material, smaller integrated circuits and the corresponding inductive element would not allow coupling of the RFID circuitry to the antenna of the RFID tag due to an impedance mismatch. As a result, with a radio module comprising the magnetically permeable material, smaller RFID tags may be obtained.

[0019] In some of these examples, the magnetically permeable material may be a ferrite material selected from the following: ferrite Fe, manganese-zinc ferrite Mn3Zn(i-g) Fe2O4, nickel-zinc ferrite NisZn(i-6) Fe2O4, cobalt ferrite, strontium ferrite, barium ferrite, or combinations thereof.

[0020] The term “magnetically permeable material” may refer to a material with a magnetic permeability greater than a magnetic permeability of the air, in other words, a relative permeability of the magnetically permeable material -rmaterlal'sgreater than a relative permeability of the air

[0021] Specifically, in some examples of the disclosure, the section of the conductive wire supported by the package of the radio module may comprise one or more turns around the package, e.g. exactly two turns, exactly three turns, or exactly four turns. Thus, in some examples, multiple turns and specific arrangements, e.g. inclination of the conductive wire or relative orientation between the conductive wire and the inductive element, may be provided to increase the efficiency of the inductive coupling. In examples, when the section of the conductive wire supported by the package comprises two or more turns around the package, the resulting loops formed around the package may be substantially of equal diameter. As a result, the package, which is a three-dimensional arrangement, may prevent that each additional loop formed by each additional turn made by the section of the conductive wire around the package is farther away from the package comprising, at least in part, the integrated circuit and the inductive element. Therefore, inductive coupling may be improved and an RFID tag with improved read range may be obtained.

[0022] In examples of the disclosure, the conductive wire may comprise an insulating outer layer. Such an insulating layer may be particularly useful in designs comprising multiple turns. Thus, by providing an insulating material on the outer surface of the conductive wire, short circuits resulting from direct physical contact between different parts of the conductive wire may be avoided. The insulating outer layer may comprise one or more of the following: an enamel, an insulating and sealing polyurethane varnish, an anticorrosive paint, a silicone adhesive, a silicone sealants, nylon or polyimide (PI).

[0023] In still another aspect of the disclosure, a method of manufacturing a radio frequency identification, RFID, tag is provided. The method comprises providing a radio module for the RFID tag, wherein the radio module comprises an integrated circuit, comprising RFID circuitry. The radio module further comprises an inductive element configured to enable inductive coupling of the RFID circuitry, and a package configured to encapsulate, at least in part, theintegrated circuit and the inductive element. The method further comprises arranging a section of a conductive wire such that the section of the conductive wire is supported by the package.

[0024] According to this aspect of the disclosure, a versatile method of production is provided. In particular, the mounting of the conductive wire, which acts as the antenna, on the package itself optimizes the number of steps as it avoids separate steps for attaching the different elements, i.e. the antenna and the IC, to a substrate. Consequently, examples of the method are suitable for mass production, and it provides cost-effective integration. Furthermore, as shown in more detail below, the arrangement of the section of the conductive wire on the package can be conveniently automated, thus increasing the reliability and the overall quality of the manufacturing process. In summary, this type of antenna is considerably more suitable for serial production (i.e., mass production that is organized as a continuous process) than an antenna requiring retention elements for securing the antenna to a substrate.

[0025] As will be shown in more detail in reference to some examples, different alternatives may be envisaged to arrange the section of the conductive wire around the package such that the package supports the conductive wire. In different examples, the conductive wire may be wound, knotted, or stitched to the package.

[0026] In examples of the disclosure, the inductive element may be an integrated inductive element incorporated in the integrated circuit containing the RFID circuitry or it may be separate from such integrated circuit. In the former case, the package of the radio module may be the package of the integrated circuit itself, i.e. no further package may be provided. In the latter case, the package of the radio module may be a dedicated package provided to encapsulate the IC, with its corresponding package, and the inductive element. In both cases, the package of the radio module forms an outer surface of the radio module, and it provides protection against harsh environments and demanding operating conditions.

[0027] In another aspect of the disclosure, another RFID tag is provided. The RFID tag comprises a radio module comprising an integrated circuit comprising RFID circuitry. The radio module further comprises an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag. Furthermore, the radio module comprises a package configured to encapsulate, at least in part, the integrated circuit and the inductive element. The RFID tag further comprises a conductive wire, configured to act as the antenna of the RFID tag. The conductive wire comprises a section arranged substantially around the radio module. The antenna obtained with the conductive wire exhibits a longitudinal direction. The conductive wire and the radio module are arranged in an asymmetrical manner with respect to a plane,the plane being perpendicular to the longitudinal direction of the antenna and substantially aligned with the radio module.

[0028] According to this aspect of the disclosure, an RFID tag with an increased read range is provided. It has been found that an asymmetric arrangement of the antenna of the RFID tag with respect to the radio module results in an enhanced transmission coefficient.

[0029] Examples of the different aspects of the present disclosure may also be combined. Accordingly, an RFID tag may comprise a conductive wire, configured to act as the antenna of the RFID tag. The conductive wire may comprise a section supported by the package of the radio module, and it may be provided with an asymmetric arrangement with respect to the package of the radio module.

[0030] Throughout this disclosure, an asymmetric arrangement is understood as follows. The antenna exhibits a longitudinal direction, i.e. a direction in which the extension or span of the antenna is maximum. A plane is defined which is perpendicular to such longitudinal direction and which is substantially aligned with the radio module of the RFID tag. An asymmetric arrangement of the conductive wire is understood as an asymmetric arrangement with respect to such plane. In case of a circular arrangement of the conductive wire around the radio module, i.e. antenna with no defined longitudinal direction, an asymmetric arrangement is present whenever the radio module is displaced from the center of the antenna.

[0031] In some examples, the radio module may comprise a magnetically permeable material. In some variants, the magnetically permeable material may be provided in, or attached to, the package of the radio module. In other variants, the magnetically permeable material may be provided as a core, e.g. a ferrite core, which may be disposed inside the package. In some of these examples, the magnetically permeable material may be a ferrite material selected from the following: ferrite Fe, manganese-zinc ferrite MnsZn(i-6) Fe2O4, nickel-zinc ferrite NisZn(i-6) Fe2O4, cobalt ferrite, strontium ferrite, barium ferrite, or combinations thereof. The advantages described in relation to the first aspect may analogously apply to this aspect.

[0032] The RFID tag according to the present disclosure, i.e. the integrated circuit and the antenna, may be configured to operate at least in one frequency band within an ultra-high frequency (UHF) range. The UHF range covers radio frequencies from 300 MHz to 3 GHz according to International Telecommunication Union (ITU) designation. To give an example, the at least one frequency band may comprise, in part or in full, the European Union frequency band 866 MHz-869 MHz and / or United Stated frequency band 902 MHz-928 MHz. In someexamples, the antenna may be, in general, a resonant antenna able to provide one or more resonance frequencies to the RFID tag and thus one or more associated operational frequency bands.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Non-limiting examples of the present disclosure will be described in the following, with reference to the drawings, in which:Figures 1 shows a schematic representation of an example of an integrated circuit for use in an RFID tag;Figure 2 illustrates an example of an architecture of an integrated circuit for use in an RFID tag;Figures 3A - 3B illustrate an example of an RFID tag having an antenna manufactured by winding a conductive wire around a radio module of the RFID tag in a perspective view and from above, respectively;Figures 4 illustrates another example of an RFID tag having an antenna manufactured by winding a conductive wire around a radio module of the RFID tag;Figure 5 illustrates an example of an RFID tag having an antenna manufactured by forming a clove hitch knot using conductive wire around a radio module of the RFID tag in a side view;Figure 6 illustrates an example of a process of forming a clove hitch knot;Figure 7 illustrates an example of an RFID tag having an antenna manufactured by stitching a conductive wire around a radio module of the RFID tag from above;Figure 8 shows a flowchart of an example of a method of manufacturing an RFID tag;Figure 9 shows a flowchart of an example of a method of manufacturing a plurality of RFID tags;Figures 10A - 10C schematically illustrate three stages of a winding-based method of manufacturing an RFID tag according to an example;Figures 11A - 11 D schematically illustrate four stages of a knotting-based method of manufacturing an RFID tag according to a further example;Figure 12 illustrates an apparatus according to an example;Figure 13 shows a flowchart of a method of manufacturing an integrated circuit for an RFID tag according to an example;Figure 14 illustrates a comparison of performance of an RFID tag according to an example and a reference RFID tag;Figure 15 schematically illustrates an example of an RFID tag having an antenna arranged in an asymmetric manner;Figure 16 illustrates a comparison of the performance of RFID tags according to different degrees of asymmetry in the arrangement of the antenna according to an example; andFigure 17 shows an overall top-down view of a prior-art RFID tag manufactured using conventional means.DETAILED DESCRIPTION OF EXAMPLES

[0034] Reference will now be made in detail to embodiments, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation only, not as a limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure. It is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents. Furthermore, drawings are intended to illustrate the different examples and manufacturing process. For the sake of clarity, dimensions of the different elements are not at scale to facilitate identification of the different components.

[0035] Figure 1 shows a schematic representation of an example of an integrated circuit, IC, 101 for use in an RFID tag according to the disclosure. The IC 101 may comprise at least RFID circuitry 121 and an integrated (or on-chip) inductive element 122 (e.g., an integrated coil). The RFID circuitry 121 and an integrated inductive element 122 may be provided on one or more substrates 129 (comprising, e.g., a silicon substrate) of the IC 101. In this example, the integrated inductive element 122 is not an individual component manufactured separately and subsequently connected to the RFID circuitry 121. Instead, the integrated inductive element 122 may be manufactured as a part of the integrated fabrication flow of the IC 101. In other examples, a separate, i.e. not integrated inductive element may be manufactured separately from the IC 101. Such separate inductive element may then be connected to the IC101 to constitute a radio module of an RFID tag. Subsequently, in such examples, a package may be provided to encapsulate the IC 101 and the inductive element.

[0036] The integrated inductive element 122 may be configured (and arranged) to inductively couple (or equally magnetically couple) the RFID circuitry 121 wirelessly to an antenna of the RFID tag as shown in more detail in different examples below. The IC 101 and the inductive element 122 may form a radio module. Although not shown in Figure 1 , a package is provided to encapsulate the IC 101 and the inductive element 122, i.e. to encapsulate the radio module.

[0037] The integrated inductive element 122 may be made of a metal such as copper, aluminium or silver or other conductive material. The metal or metallization thickness and / or width of the integrated inductive element 122 may be at least equal to or larger than skin depth at an operating frequency of the RFID tag (e.g., 2.21 pm for copper at 866 MHz). The area covered or taken by the integrated inductive element 122, i.e., the area defined by the outer dimensions of the integrated inductive element 122, may be at least larger than 1 mm2. This area includes also the empty central part.

[0038] As shown in Figure 1 , the integrated inductive element 122 may be an integrated inductor having a shape of a spiral with one or more turns. The spiral may be a planar spiral. The (planar) spiral may be, for example, a polygonal spiral (e.g., a rectangular, square or regular polygonal spiral) or a smoothly varying spiral (e.g., a circular or elliptical spiral) or a combination of the two. The ends 125, 126 of the spiral may be connected to the RFID circuitry 121 (this connection is not shown in Figure 1). Figure 1 shows specifically, as an example, an integrated inductive element 122 having a shape of a planar rectangular spiral with two turns. The integrated inductive element 122 may be implemented in one layer or multiple layers of metallization (including, e.g., conductive vias for interconnection of metals from different layers) with insulation layers (e.g., silicon oxide, organosilicate and / or polymers) keeping the layers of metallization separated.

[0039] The integrated inductive element 122 may be an integrated inductor having a chiral shape (i.e., a shape possessing handedness). An object is chiral if it is distinguishable from its mirror image, that is, it cannot be superimposed onto it. A spiral is one example of a chiral shape. Similar to as discussed for the planar spiral, the chiral shape may be polygonal or smoothly varying or a combination of polygonal and smoothly varying sections. Other examples of possible chiral shapes usable for the integrated inductive element 122 comprise, for example, a helix.

[0040] In examples (not illustrated in Figure 1), the integrated inductive element 122 may be an integrated inductor having a shape of a loop (e.g., an open or closed loop). The loop may be, for example, a polygonal loop (e.g., a rectangular, square, or regular polygonal loop) or a smoothly varying loop (e.g., a circular or elliptical loop).

[0041] The (outer) physical dimensions (i.e., length and width) of the integrated inductive element 122 may be at least smaller than A / 5 and optionally smaller than A / 10 or smaller than A / 15, where A is the (smallest) operational wavelength of the RFID tag. Thus, the integrated inductive element 122 may be considered a distributed element, a semi-lumped element or a lumped element depending in some implementations. According to the present disclosure, a lumped element is defined as a circuit element whose largest physical dimension is equal to or smaller than A / 10 at its maximum operational frequency (i.e., A is the smallest operational wavelength). Ideally, said largest physical dimension of a lumped element should be much smaller than A / 10 (e.g., A / 20). Semi-lumped elements are circuit elements whose physical dimensions are significant relative to the operational wavelength (e.g., being larger than A / 20 or A / 10 and at least smaller than A / 4) but their operation can still be approximated as using a lumped-element model under certain conditions. A distributed element may be defined as a circuit element whose largest physical dimension is larger than A / 4 at its maximum operational frequency. Due to the significant electrical size of the distributed elements, a lumped-element model in which the passive electrical elements of electrical resistance, capacitance and inductance are assumed to be "lumped" at one point in space in a resistor, capacitor or inductor, respectively, can no longer be used. The distributed-element model is used when this assumption no longer holds, and these properties are considered to be distributed in space.

[0042] In examples (not illustrated in Figure 1), the integrated inductive element 122 may be an integrated inductor implemented using transmission lines (e.g., using very high characteristic impedance transmission lines and / or short transmission line stubs terminated in short circuit).

[0043] In examples, the IC 101 may comprise a plurality of conductive (e.g., metal) layers, a plurality of insulation (or substrate) layers and one or more conductive vias connecting the plurality of conductive layers to each other. In such implementations, the integrated inductive element 122 may comprise a spiral section 123 comprised in a first conductive layer of the IC 101. The integrated inductive element 122 may further comprise one or more interconnect sections comprised in one or more conductive layers of the IC 101 , respectively, and / or one or more conductive vias comprised in one or more via layers of the IC 101 so as to enableconnecting the RFID circuitry 121 between an inner (or centermost) end 126 of the spiral section 123 and an outer end 125 of the spiral section 123.

[0044] The integrated inductive element 122 may be configured and arranged to surround the RFID circuitry 121 fully or at least partly (e.g., on one to three sides). This provides the benefit of minimization of the area required by the IC 101 (i.e., the minimization of the area of the semiconductor wafer).

[0045] The IC 101 (including the RFID circuitry 121 and the integrated inductive element 122), or at least the RFID circuitry 121 and the integrated inductive element 122 of the IC 101 , may be manufactured using a single fully integrated fabrication flow. Thus, the integrated inductive element 122 forms, as implied by the term “integrated”, an integrated (and intrinsic) part of the IC 101. In other words, the integrated inductive element 122 is not attached to the RFID circuitry 121 in a separate manufacturing step, e.g., by soldering. The integrated inductive element 122 may be formed, for example, in the interconnect fabrication step (also called the back end of line, BEOL, fabrication step) of a typical IC manufacturing process. The same IC manufacturing process is used also for forming the RFID circuitry 121 , which considerably simplifies the manufacturing process of the RFID tag 100. This also enables improving the production reliability by enabling relaxing the accuracy, time and cost requirements for accurately positioning the IC. In addition, compared to RFID tags where the IC would be physically and electrically connected to the antenna, the positioning of the chip module requires less precision, allowing a certain tolerance (in the order of hundreds of microns) while maintaining proper coupling between the integrated inductive element 122 and the antenna which leads to greater efficiency in mass production.

[0046] The RFID circuitry 121 of the IC 101 may comprise any circuitry commonly found in any conventional (passive or active) RFID tags for enabling RFID functionality (e.g., energy harvesting from signal received via an RFID tag antenna and the integrated inductive element 122, storing ID data and optionally additional data and performing data processing functions). The RFID circuitry 121 may be at least configured to receive RF energy from a received signal for powering itself, modulate the RF energy and transmit (or reflect) it back. The reflected RF signal may carry modulated data (i.e., data encoded in the form of changes in amplitude, frequency, or phase of the RF signal). The RFID circuitry 121 may comprise one or more individual circuits. The RFID circuitry may comprise analog and / or digital circuitry. For example, the RFID circuitry 121 may comprise one or more passive (integrated) circuit components such as one or more resistors, one or more inductors and / or one or more capacitors. Additionally or alternatively, the RFID circuitry 121 may comprise one or more active (integrated) circuitcomponents such as one or more transistors, one or more diodes, one or more memory cells and / or one or more logic gates. The RFID circuitry 121 may be configured to implement modulation, demodulation, energy harvesting, digital baseband processing, memory storage and / or one or more clocks. Individual circuit components may be connected to each other using additional interconnect layers and associated vias. One exemplary implementation of the RFID circuitry 121 of the IC 101 is discussed below in connection with element 201 of Figure 2.

[0047] The IC 101 (i.e. , the radio module) may further comprise an encapsulating element (e.g., an IC package or packaging) fully encapsulating all other elements of the IC 101 (comprising at least the RFID circuitry 121 and the integrated inductive element 122) leaving no conductive (and / or active) part of the IC 101 exposed. The expression “all other elements of the IC 101” refers here to elements of the IC 101 excluding the IC package itself. According to a general definition, an IC package (also known as a semiconductor package or a chip package) is a protective housing or enclosure that encapsulates and houses an integrated circuit or microchip. It should be noted that, in conventional ICs for RFID tags, a conductive pad for an antenna contact must be left exposed. The package of the IC 101 provides enhanced environmental robustness compared to such known packages. The IC package may be made of, e.g., glass epoxy resin or polypropylene sulfide using injection moulding.

[0048] In examples comprising a non-integrated inductive element, similar materials and considerations as those described for the integrated inductive element 122 may be taken into account.

[0049] Figure 2 illustrates an exemplary architecture of an integrated circuit 200 according to an example. The illustrated architecture may be employed, for example, in connection with the IC 101 of Figure 1.

[0050] Referring to Figure 2, the integrated circuit 200 comprises, similar to what was described in connection with Figure 1 , RFID circuitry 201 and an (integrated) inductive element 210. The RFID circuitry 201 comprises an energy harvesting and analog RF system 220, a digital control and processing unit 230 and at least one memory 240. The at least one memory 240 may be or comprise at least one electrically erasable programmable read-only memory (EEPROM). The inductive element 210 comprises an inductor 211 (or an integrated inductor 211).

[0051] The energy harvesting and analog RF system 220 is configured to receive and transmit radio signals via the inductive element 210. To enable this, the energy harvesting and analog RF system 220 comprises a first radio receiver (or transceiver) 221 for radio signalreception and a second radio transmitter (or transceiver) 226 for radio signal transmission.Alternatively, a single radio transceiver comprising both elements 221 , 226 may be provided.

[0052] The energy harvesting and analog RF system 220 further comprises a rectifier 225, a regulator 222, a demodulation unit 223 and a modulation unit 224. The rectifier 225 is configured to convert the received radio signal into direct current (DC) power for powering the RFID circuitry 201. The regulator 222 (or voltage regulator) is configured to stabilize and regulate the voltage output from the rectifier 225 (or an energy storage capacitor if one is provided) so as to provide a consistent voltage level for the RFID circuitry's analog and digital circuitry. The demodulation unit 223 is configured to demodulate the received radio signal while the modulation unit 224 is configured to modulate the radio signal to be transmitted.

[0053] In some examples, the RFID circuitry may further comprise an energy storage capacitor for storing harvested energy.

[0054] The digital control and processing unit 230 may comprise at least one processor. The at least one memory 240 and the computer program code (software) maintained in the at least one memory 240 may be configured, with the at least one processor, to cause the RFID circuitry 201 to perform various RFID functionalities. Said RFID functionalities performed by the RFID circuitry 201 may comprise at least receiving a demodulated signal from the demodulation unit 223 and causing the modulation unit 224 to modulate a reflected radio signal with data (e.g., at least ID data) stored in the at least one memory 240 using power harvested from the received radio signal. Which data is used for the modulation may depend on the received demodulated signal.

[0055] While implementing the inductive element 122, 210 as an integrated inductive element of the IC 101 , 200 as described in connection with Figures 1 and 2 provides the benefit of ease of manufacturing of the radio module of the RFID tag (i.e. , the RFID tag excluding the antenna), it should be emphasized again that, in examples, the inductive element may be a non-integrated inductive element separate (i.e., distinct) from the IC. Said separate inductive element may be attached or fixed to the IC (e.g., to an encapsulating element thereof), for example, using an adhesive or mechanical fixing means. Said separate conductive element should be electrically connected to the RFID circuitry of the IC (e.g., via soldering) for enabling inductive coupling of the IC to the antenna. The separate inductive element may be provided on a separate (dielectric) substrate. In any case, an encapsulating element or package may be provided to encapsulate both the IC and the inductive element at least partially, thus resulting in a substantially monolithic radio module. In other words, a radio module may beobtained which may be equivalent to the radio module resulting from an integrated inductive element.

[0056] Regarding the arrangement of the antenna of the RFID tag, and before providing examples according to the present disclosure, Figure 17 provides a schematic view of an RFI D tag 100’ according to the prior-art. Thus, the RFID tag 100’ comprises at least three parts: an IC 10T, an antenna 102’, and a substrate 103’. The IC 10T and the antenna 102’ are each individually fixed to the substrate 103’. In particular, gluing or sewing may be employed to fix the IC 10T and the antenna 102’ in different examples of the prior art. As also shown in Figure 15, the antenna 102’ is provided to surround the IC 10T in a substantially symmetric arrangement.

[0057] Figures 3A and 3B illustrate an example of an RFID tag 600 in a perspective view and from above, respectively. In this example, an antenna of the RFID tag may be provided by winding a conductive wire 603 around a radio module of the RFID tag 600. The RFID tag 600 may comprise a radio module 601 and a conductive wire 603 acting as the antenna of the RFID tag 600. The radio module 601 comprises an integrated circuit 602 comprising RFID circuitry and an inductive element configured to inductively couple the RFID circuitry to the section 604 of the conductive wire 603. In examples, the inductive element may be provided separate from the integrated circuit 602. Moreover, the radio module also comprises a package 605, configured to encapsulate the integrated circuit 602 and, in examples comprising a nonintegrated inductive element, the inductive element. The package 605 may be or comprise an IC package of the integrated circuit of the radio module 601. The package 605 may be, for example, made of a non-conductive material such as glass epoxy resin or polypropylene sulfide, for example, by injection moulding.

[0058] As also shown in Figures 3A and 3B, the conductive wire 603 may comprise a section 604 supported by the package 605 of the radio module. Specifically, as also shown in Figures 3A and 3B, the section 604 of the conductive wire 603 is wound on the surface of the package 605 of the radio module 601. Furthermore, the conductive wire 603 also comprises two non-wound (e.g., straight) end sections 609, 610 at the two ends of the conductive wire 603. In the example shown in Figures 3A and 3B, the end sections 609, 610 may have a substantially equal length. The antenna of the RFID tag may then be formed by the section 604 and by the two straight sections 609, 610. Accordingly, in this example, the antenna may be arranged substantially symmetrical relative to the package 605. In other examples (see, e.g. Figure 15 and associated description below), two straight sections with different length may be used, thus resulting in an asymmetric arrangement of the antenna.

[0059] In the example shown in Figures 3A and 3B, the section 604 of the conductive wire 603 supported by the package 605 of the radio module comprises multiple turns around the package 605. In particular, in this example, the section 604 of the conductive wire 603 may comprise four turns. The number of turns may be dependent on the specific application of the RFID tag. In any case, due to the three-dimensional arrangement of the RFID tag of Figure 3A and 3B, in those examples including more than one turn, all the turns may substantially be at the same distance from the IC 602, i.e. from the inductive element. Accordingly, proper adjustment of the inductive or magnetic coupling may be achieved. This is compared with the solutions of the prior art, in which the two-dimensional arrangement imposes a constraint. Thus, even if multiple turns may also be provided in known designs, only the first turn is at the shortest distance of the IC whereas the consecutive turns are arranged at increasing distances from the IC, thus reducing the potential improvement resulting from the provision of additional turns.

[0060] In examples of the present disclosure, the package 605 may comprise a first flange 607, a second flange 608 and a center portion 606 arranged between the first flange 607 and the second flange 608. The first flange 607 and the second flange 608 may extend outwards from the center portion 606. The section 604 of conductive wire 603 may be supported by the center portion 606. In particular, in the example shown in Figures 3A and 3B, the section 604 of the conductive wire 603 may be wound around the center portion 606. Other examples, not comprising winding of the conductive wire 603, will be provided below. Such an arrangement with a first flange 607 and second flange 608 may be advantageous in order to hold the conductive wire 603 and, more specifically, the section 604 of the conductive wire 603 substantially in place. Furthermore, the first flange 607 and second flange 608 may also facilitate the winding of the conductive wire 603 during the manufacturing process by acting as guiding elements.

[0061] As also shown in Figures 3A and 3B, the package 605 may have a substantially cylindrical shape with a right cylinder in the center portion 606. The first flange 607 and the second flange 608 may be arranged at both longitudinal ends of the center portion 606 and the flange may extend radially outward. In examples, the center portion 606 of the package 605 may have a shape of any (right) prism (e.g., a rectangular cuboid or an n-gonal or triangular (right) prism).

[0062] In examples of the disclosure, the package 605 may be a monolithic element or an element composed of multiple separate parts (e.g., separate parts forming the center portion606 and the two flanges 607, 608) fixed together, e.g., via an adhesive or mechanical fixing means.

[0063] In the example of Figures 3A and 3B, a distance which is not to scale is depicted between the section 604 of the conductive wire 603 and the two flanges 607, 608 for clarity of presentation. Nevertheless, in some examples, the conductive wire 603 may be wound between the two flanges 607, 608 so that the conductive wire 603 is in-contact with the two flanges 607, 608 (and thus the two flanges 607, 608 directly prevent movement of the conductive wire 603). Such examples may exhibit increased reliability due to a more controlled interaction between the inductive element in the IC 602 and the antenna, i.e. the sections 604, 609 and 610 of the conductive wire 603.

[0064] In some examples, the package 605 may not comprise any flange or it may comprise a flange only at one end.

[0065] In some examples, the height of the RFID tag 600 (i.e., of the package 605 thereof) may be larger than or equal to 0.2 mm and / or smaller than or equal to 2.0 mm. Additionally or alternatively, the width of the RFID tag 600 (i.e., of the package 605 thereof) may be larger than or equal to 0.4 mm and / or smaller than or equal to 10.0 mm.

[0066] Figure 4 illustrates another example of an RFID tag 700 having an antenna manufactured by winding a conductive wire 703 around a radio module 701 of the RFID tag 700. In particular, as in the previous example, a section 704 of the conductive wire 703 may be supported by a package 705 of the radio module 701. The package 705 is used to encapsulate a radio module, i.e. to encapsulate an IC comprising RFID circuitry and an inductive element (not shown in Figure 4).

[0067] In this example, the surface of the package 705 may comprise one or more grooves 715 for positioning the conductive wire 703. Specifically, a section 704 of the conductive wire 703 may be supported by the package 705 and it may be guided along the grooves 715.

[0068] Different advantages may arise from the provision of such grooves 715 on the surface of the package 705 supporting the conductive wire 703. The grooves 715 may provide an anchoring point for the section 704 of the conductive wire 703 that may prevent undesired movements, thus increasing reliability of the RFID tag. Furthermore, as already explained with reference to Figures 3A and 3B, a plurality of turns may be provided in some examples to improve the efficiency of the inductive coupling. In such examples, the provision of grooves 715 may facilitate the separation of the different turns in a vertical direction, i.e. in a direction substantially perpendicular to the plane of the turns. The provision of such spacing may preventoverlapping or contact between the different turns. As a result, the provision of insulating material on the conductive wire 703 to prevent short-circuits may not be necessary. Consequently, an easier and more cost-effective manufacturing process may be obtained. As still another advantageous effect, the grooves 715 may serve as a guiding element for the conductive wire 703 during manufacturing of the corresponding RFID tag 700.

[0069] Specifically, the RFID tag 700 may comprise a package 705 wherein the surface of the package 705 may comprise two grooves 715 and the section 704 of the conductive wire may be wound along the two grooves 715 so as to define two non-overlapping turns. By providing two turns instead of one turn, an improved inductive coupling may be provided. Additional grooves 715 may be provided for the provision of additional turns. In particular, the number of turns may be dependent on the details of the design of the RFID tag. Specifically, the value of the impedances of the inductive element and the antenna resulting from the winding of the conductive wire may be considered to determine the optimum number of turns.

[0070] As also shown in Figure 4, the RFID tag 700 may comprise a substrate 725. The substrate 725 may be attached or fixed to the package 705 of the RFID tag 700. The substrate 725 may be fixed, e.g., using an adhesive or using mechanical fixing means. The substrate 725 may be, e.g., a textile, paper, or plastic substrate.

[0071] In some other examples, such as those shown in relation to Figures 3A and 3B, the substrate 725 may be omitted.

[0072] Figure 5 illustrates another example of an RFID tag 1000. The RFID tag comprises a radio module 1001 which can be a similar or equivalent to the ones used in previously shown examples. In this example, an antenna may be manufactured by knotting a conductive wire 1003. Moreover, the RFID tag 1000 comprises a package 1005 encapsulating the integrated circuit 1002 which may include an integrated inductive element. In examples comprising a nonintegrated inductive element, the package 1005 may also be provided to encapsulate the integrated circuit and the inductive element. Thus, in this example, a section 1004 of a conductive wire 1003 may be knotted around a surface of the package 1005. Specifically, the section 1004 of conductive wire 1003 may be knotted with a clove hitch knot.

[0073] Although not shown in Figure 5, one or more grooves may also be provided on the surface of the package 1005 in this example, specifically in a central part of the package 1005, to guide the knotted section 1004 of the conductive wire 1003. As shown in Figure 5, the conductive wire 1003 also comprises two non-knotted (e.g., straight) end sections 1009, 1010 at the two ends of the conductive wire 1003. These end sections 1009, 1010 may have equallength. Accordingly, the antenna of the RFID tag 1000 may comprise the knotted section 1004 and the two straight section 1009, 1010. Accordingly, in this example, the antenna may be arranged substantially symmetrically relative to the radio module 1001 and, more particularly, to the package 1005. In other variants (see, e.g. Figure 15), end sections with different lengths may be used, thus resulting in an asymmetric arrangement of the antenna.

[0074] The radio module 1001 may comprise an integrated circuit 1002 comprising RFID circuitry and an integrated (i.e. , on-chip) inductive element configured to inductively couple the RFID circuitry wirelessly to the conductive wire section 1003 of the RFID tag 1000. As already mentioned, the inductive element may be separate from the integrated circuit 1002.

[0075] As shown in Figure 5, and similarly to the examples described with reference to Figures 3A and 3B, the package 1005 may comprise a first flange 1007, a second flange 1008 and a center portion 1006 between the first flange 1007 and the second flange 1008. The first flange 1007 and the second flange 1008 may extend outwards from the center portion 1006. The section 1004 of conductive wire 1003 supported by the package 1005, may be specifically supported by the center portion 1006. In particular, the section 1004 of conductive wire 1003 may be, in this example, knotted around the center section.

[0076] As explained with reference to Figures 3A and 3B, the first flange 1007 and the second flange 1008 may hold the conductive wire 1003 in place during operation of the RFID tag 1000. Furthermore, the first flange 1007 and the second flange 1008 may also help for guiding the conductive wire 1003 during the winding process.

[0077] Specifically in Figure 5, the package 1005 may have a shape of a right cylinder at its center portion 1006 with (external) flanges 1007, 1008 arranged at both longitudinal ends of the center portion 1006.

[0078] Regarding the knot, different types of knots may be provided to obtain the desired distribution of the section 1004 of conductive wire. In particular, a knot may be selected such that the right amount of wire is arranged substantially aligned with the IC 1002. Furthermore, the knot may also be selected by taking into account the inclination of the different parts of the section 1004 of the conductive wire. Specifically, a desired relative orientation between the inductive element and the antenna may be achieved.

[0079] Figure 6 illustrates one specific type of knot which may be employed in examples comprising knotting of the conductive wire. In particular, the knot shown in Figure 6 is a clove hitch knot. The clove hitch knot has the beneficial property that it can be tied easily to a middle of a wire (without needing access to either of the ends of the wire) as long as at least one endof the object around which the knot is to be formed is accessible (i.e., a wire loop can be passed through it). Furthermore, by applying a clove hitch knot, two turns are easily obtained, thus potentially increasing the inductive coupling. Specifically, Figure 6 illustrates three consecutive phases or steps 801 , 802, 803 of tying the clove hitch knot. In the simplistic example of Figure 6, a wire is knotted around a simple post which may correspond to, e.g. the package 1005 of the radio module 1001 in different examples.

[0080] In the first step 801 , the wire is wrapped once around the post so that the working end of the wire (shown on the left in step 801 of Figure 6) lies below the standing end of the wire (shown on the right in step 801 of Figure 6). In the second and third steps 802, 803, the working end of the wire is wrapped a second time around the post so that the second wrap is above the first one. The working end of the wire is tucked under the second wrap so that working end extends from a middle of the knot (i.e., it is not the top wire). Finally, the wire is pulled tight to form the clove hitch knot. In summary, the clove hitch knot is formed by crossing the wire over the post (i.e., the radio module in examples), wrapping it behind, crossing over again, tucking the working end under the last wrap and pull it tight to form the clove hitch. The use of a clove hitch knot may be particularly suitable for automation processes due to its relative simplicity.

[0081] Figure 7 illustrates still another example of an RFID tag 1100 having an antenna which, in this example, may be manufactured by stitching a conductive wire 1103 around a package 1105 of the RFID tag 1100. To this end, the package 1105 may comprise a plurality of holes 1111 and a section 1104 of conductive wire 1103 may be stitched on the package 1105 via the holes 1111. Specifically, the package 1105 may comprise a center portion 1106 (see dashed line) and a flange 1107 extending outwards from the center portion 1106. The flange 1107 may comprise the plurality of holes 1111.

[0082] Thus, in the example of Figure 7, the section 1104 of the conductive wire 1103, which act as the antenna of the RFI D tag 1100, may also substantially surround a radio module 1101. In an equivalent manner as in previous examples, the radio module 1101 may comprise an integrated circuit 1102 comprising RFID circuitry and an integrated (i.e., on-chip) inductive element configured to inductively couple the RFID circuitry wirelessly to the conductive wire section 1104 of the RFID tag 1100. The section 1104 of the conductive wire 1103 may travel (substantially) around at least the integrated circuit 1102 of the radio module 1101. It should be noted that there may be a distance offset (in the direction towards / away from the viewer in Figure 7) between a plane defined by the stitched section 1104 of the conductive wire 1103 and the integrated circuit 1102 (or the inductive element thereof). As shown in Figure 7, theconductive wire 1103 may also comprise two non-stitched (e.g., straight) end sections 1109,1110 at the two ends of the conductive wire 1103. These end sections 1109, 1110 may have equal length and, together with the stitched section 1104, may constitute the antenna of the RFID tag 1100. Accordingly, in this example, the antenna may be arranged substantially symmetrically relative to the radio module 1101 and, more particularly, to the package 1105. In other variants (see, e.g. Figure 16), non-stitched end sections with different lengths may be used, thus resulting in an asymmetric arrangement of the antenna.

[0083] The package 1105 encapsulating (i.e., surrounding) the integrated circuit 1102 may be similar to the examples discussed in connection with Figures 3A, 3B or 5. As described above, the package 1105 may comprise a first flange 1107, a second flange (not visible) and a center portion 1106 between the first flange 1107 and the second flange. As seen in Figure 7, the plurality of stitching holes 1111 may be provided on the first flange 1107 and thus the conductive wire 1103 may be stitched onto the first flange 1107.

[0084] The package 1105 or the first flange 1107 may comprise a plurality of holes 1111 (called stitching holes herein). Said plurality of stitching holes 1111 may have been prepared before the stitching, e.g., by drilling or punching. Alternatively, the plurality of stitching holes1111 may be formed during the stitching itself, e.g., by forcing a needle through the package 1105. In the latter case, the package 1105 may be made of a sufficiently pliable material for enabling the stitching (without use of excessive force).

[0085] While the example of Figure 7 shows package 1105 with 12 stitching holes 1111 , in other examples, two or more stitching holes 1111 or three or more stitching holes 1111 or four or more stitching holes 1111 may be provided or formed on the package 1105 of the radio module 1101. In any of said cases, the stitching holes 1111 may be arranged (e.g., rotationally symmetrically) around a longitudinal (center) axis of the package 1105, as shown in Figure 7.

[0086] Specifically, the package 1105 may have a section 1106 with a shape of a right cylinder with flanges arranged at both longitudinal ends of the right cylinder. The package 1105 may correspond to the package 605 as described in connection with Figures 3A and 3B (apart from the stitching holes 1111).

[0087] In examples, the second flange (to which the conductive wire 1103 is not stitched and which is obstructed from view in Figure 7) may be omitted.

[0088] In some examples such as the one illustrated in Figure 7, the stitching path (i.e., the path traced by the stitches) may follow an outer edge of the first flange 1107 so that the stitched conductive wire is at a pre-defined distance from the outer edge. In the example of Figure 7,the first flange 1107 may have a cylindrical shape and, thus, the stitching path may have the shape of a circle (with said circle having a smaller diameter compared to a diameter of the cylindrical flange 1107).

[0089] The stitches formed by the conductive wire 1103 may be non-functional or non-seam stitches, that is, stitches which do not serve to fix any two objects together. Alternatively, the stitches formed by the conductive wire 1103 may be functional or seam stitches for connecting the radio module 1101 to a substrate (being, e.g., a flexible substrate such as a textile, paper or plastic substrate). In either case, the conductive wire 1103 still acts as the antenna of the RFID tag 1100.

[0090] While in the example shown in Figure 7, the stitched section 1104 of the conductive wire 1103 is arranged to surround the integrated circuit 1102 for a single turn, in other examples, the stitched section 1104 of the conductive wire may surround the integrated circuit 1102 for a plurality of turns (e.g., by forming a concentric circular spiral or other concentric spiral around a longitudinal central axis of the package 1105).

[0091] Moreover, while in the example shown in Figure 7, the integrated circuit 1102 comprises an inductive element for coupling to the conductive wire 1103, in other examples, the inductive element may be an inductive element separate from the integrated circuit 1102. In such examples, the stitched section 1104 of the conductive wire 1103 may be arranged to substantially surround at least the inductive element.

[0092] The examples of Figure 7 may offer some advantages regarding durability and reliability of the RFI D tag 1100. Thus, by stitching a section 1104 of the conductive wire 1103, a very precise location of the antenna may be provided. Furthermore, stitching also provides a robust fixation in front of demanding operating conditions.

[0093] In examples of the present disclosure, and regardless of whether winding, knotting or stitching is employed, the conductive wire 603, 703, 1003, 1103 may comprise one or more separate conductive elements (e.g., one or more conductive strands). The conductive wire 603, 703, 1003, 1103 may be flexible and it may be a metal or metallized wire or a wire made of a conductive alloy (e.g., steel). Alternatively, the conductive wire 603, 703, 1003, 1103 may be a conductive wire based on a fiber thread (e.g., polyester or acrylic) integrated with a metal such as copper or nickel (e.g., through plating, printing, or winding). For example, the conductive wire may be copper wire or aluminum wire. The thickness of the conductive wire 603, 703, 1003, 1103 may be at least equal to or larger than skin depth at an operating frequency of the RFID tag (e.g., 2.21 pm for copper at 866 MHz).

[0094] In some examples, the conductive wire 603, 703, 1003, 1103 may be thicker than 5 pm and / or have a total length greater than the length needed to do one turn around the package 605, 705, 1005, 1105. Considering, for example, a package 605, 705, 1005, 1105 with a circular shape, the wire may have a length in the range of 2nr where r is the radius of the radio module. Specifically, the length of the wire may be comprised between 0.8 mm and 50 cm, more specifically within the range of 5 cm to 30 cm (e.g., 24 cm). The total length of the conductive wire 603, 703, 1003, 1103 may be substantially equal to A / 2, where A is an operational wavelength of the corresponding antenna.

[0095] Figure 8 illustrates a method 2000 of manufacturing an RFID tag according to an example. The manufactured RFID tag may be an RFID tag as discussed in connection with any of the above-mentioned examples. Furthermore, the method may be carried out manually or in a production line in an automated manner. The method comprises, in block 2100, providing a radio module for the RFID tag, wherein the radio module comprises an integrated circuit, comprising RFID circuitry, an inductive element configured to enable inductive coupling of the RFID circuitry, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element. Subsequently, block 2200 of the method 2000 comprises arranging a section of a conductive wire such that the section of the conductive wire is supported by the package.

[0096] In examples of the method 2000, the radio module for the RFID tag may be assumed to be initially arranged in a pre-defined (source) location. Consequently, providing the radio module in block 2100 may comprise picking up the radio module from such pre-defined location and placing the radio module at a pre-defined (target) location. This step may be carried out manually (i.e. , by a human) or using an automated picking and placing system. The automated picking and placing system may be configured to pick the radio module arranged in a predefined (source) location and place it to a pre-defined (target) location.

[0097] The automated picking and placing system may comprise a pick-and-place machine (equally called a surface-mount technology, SMT, component placement system). According to a general definition, a pick-and-place machine is a type of industrial automation equipment used in manufacturing and assembly processes, particularly in electronics and semiconductor industries. The primary function of a pick-and-place machine is to automatically pick up components (e.g., ICs) from a supply source and accurately place them onto a target location. The pick-and-place machine may typically comprise a robotic arm or a gantry system equipped with a pickup nozzle or tool for picking up components as well as a control computer configured to control the operation of the robotic arm or gantry system and the pickup nozzle or tool. Thepickup nozzle or tool may be, e.g., a vacuum nozzle or a mechanical gripper or gripping tool (e.g., tweezers).

[0098] Accordingly, in this example, the arrangement of the section of conductive wire in block 2200 may be carried out once the radio module is placed in the pre-defined (target) location. The section of the conductive wire arranged around the radio module, thus, forms an antenna of the RFID tag. As already indicated, the arranging may comprise winding, knotting or stitching the section of conductive wire for one or more turns around the radio module placed to the pre-defined location.

[0099] In some examples, the arranging in block 2200 may be carried out using automated wire mounting systems (e.g., automated wire winding, knotting or stitching systems), as will be described below in further detail. In other examples, the winding, knotting or stitching may be carried out manually by a human.

[0100] In still another example, the section of the conductive wire may be a part of a longer stretch of conductive wire. A first end of the conductive wire may be wound around a supply reel of a wire reeling system and a second end of the conductive wire may be wound around a take-up reel of the wire reeling system. In this example, the method may further comprise, following the arranging of the section of the conductive wire, reeling, using the wire reeling system, the conductive wire from the supply reel to the take-up reel so as to move the radio module towards the take-up reel.

[0101] A section of the conductive wire, comprising the section of the conductive wire supported by the package and two end sections, may be cut out of this longer stretch of conductive wire following the arranging in block 2200. This cut section may then form the antenna of the RFID tag.

[0102] As explained with reference to Figures 3-7, the section of the conductive wire may be supported by the package of the radio module in a number of ways. Thus, in an example, arranging the section of the conductive wire in block 2200 of the method 2000 may comprise winding the conductive wire for one or more turns on the surface of the package. Besides, in some examples, the section of the conductive wire may be adhesively mounted on the package. Hence, in cases comprising simply winding of the conductive wire, robustness of the RFID tag may be improved by using an adhesive to ensure a proper fixation of the antenna. This may be particularly useful for RFID tags intended for applications in harsh environments and / or with high vibrations or movements.

[0103] Furthermore, in examples of the method 2000, arranging the section of the conductive wire in block 2200 may comprise using an automated wire mounting system for winding the section of the conductive wire. Specifically, the automated wire mounting system may comprise a movable guide comprising a through hole for guiding the conductive wire around the package, or one or more articulated robotic members, the articulated robotic members comprising a gripping mechanism for gripping the conductive wire and for moving the gripped conductive wire around the package of the radio module. Such examples will be described later on with reference to Figures 10A-10C and 11A-11 D. In other examples, arranging the section of the conductive wire in block 2200 may comprise a manual process.

[0104] The automated wire mounting system, e.g. the movable guide or the robotic articulated members, may be configured to be rotatable around a pre-defined location. The radio module of the RFI D may then be provided at such pre-defined location and the automated wire mounting system may be configured to rotate the movable member or the articulated robotic members around the radio module placed at the pre-defined location for arranging the section of the conductive wire around the package of radio module. The operation of the automated wire winding system may be controlled, e.g., by a dedicated control computing device or a central control computing device of the manufacturing system.

[0105] In some examples, the automated wire mounting system may also be configured to move (slightly) in a direction orthogonal to a rotation plane during the arranging of the section of conductive wire. Specifically, such movement may be carried out in examples comprising winding of the section of conductive wire around the package. Thus, upon completion of a full rotation, the automated wire mounting system may displace the conductive wire so that a plurality of turns or loops of the conductive wire can be supported by the package. The turns may accordingly be provided in an adjacent manner but with no overlapping. The distance of this linear motion per rotation may be larger than or equal to a width of the conductive wire. This linear motion may also be controlled by the dedicated control computing device or the central control computing device of the manufacturing system. Alternatively, the linear motion may be a part of mechanical design of the rotating member.

[0106] In other examples, arranging the section of the conductive wire in block 2200 may not comprise winding but knotting the conductive wire around a surface of the package. In these examples, the conductive wire may comprise an insulating layer so as to prevent the conductive wire from forming a short circuit with itself. As in the previous example, the radio module may also be placed at a pre-defined location, and an automated wire mounting systemmay be provided to automatically knot the section of conductive wire. In some other examples, manual stitching may be used instead of an automated wire mounting system.

[0107] The formed knot may be, for example, a clove hitch knot (as shown in Figure 6), a bowline on a bight, a midshipman’s hitch, round turn and two half hitches, a taut-line hitch, a rolling hitch or a Canadian jam knot. In some examples, the formed knot may be specifically one of the clove hitch knot, the round turn and two half hitches or the rolling hitch. These three alternatives may be considered to provide enhanced inductive coupling between the section of the conductive wire and the inductive element of the radio module. In connecting with any of these knotting-based examples, the conductive wire may have an insulating layer so as to prevent the conductive wire forming a short circuit with itself. The operation of the automated wire mounting system may be controlled, e.g., by a dedicated control computing device or a central control computing device of the manufacturing system.

[0108] In examples comprising knotting, the automated wire mounting system may comprise one or more articulating members having (e.g., at their distal end) a gripping mechanism (e.g., tweezers) for gripping the conductive wire during the knotting. Such automated wire mounting system may be configured to grip the conductive wire and move the one or more articulating members while gripping the conductive wire around the package of the radio module placed at a pre-defined location so as to form a knot around the package. Each of the one or more articulating members may be, for example, a (programmable) articular robotic arm. The one or more articulating members (or at least one of them) may be configured to be maneuverable around a pre-defined location. The operation of the automated wire knotting system may be controlled, e.g., by a dedicated control computing device or a central control computing device of the manufacturing system.

[0109] In yet further examples, arranging the section of the conductive wire in block 2200 of the method 2000 may comprise stitching the section of conductive wire through a plurality of holes. Specifically, in a first variant of this example, stitching may be carried out by puncturing the package during the stitching for creating the plurality of holes. In a second variant, a plurality of pre-prepared holes may be provided on the package before the stitching. In the former case, the package may be made of a sufficiently pliable material for enabling the stitching. In the latter case, the holes may be defined in the package after fabrication of the same by, e.g. machining or drilling, or the package may be fabricated, e.g. by moulding, with a plurality of holes.

[0110] As in previous examples, the radio module may be placed at a pre-defined location manually (i.e. , by a human) or by means of an automated system. Furthermore, and as alreadydescribed in reference to the RFID tag example of Figure 7, the conductive wire may be stitched onto a flange of the package of the radio module so that the conductive wire substantially surrounds the IC and the inductive element of the radio module.

[0111] The stitching may be performed, in some examples, using an automated stitching or sewing system. The automated stitching system may comprise one or more articulating (robotic) members having (e.g., at their distal end) a gripping mechanism (e.g., tweezers) for gripping a sewing needle onto which the conductive wire may be attached. Alternatively, instead of said gripping mechanism, the sewing needle may be integrated directly onto the articulating (robotic) member (e.g., to its distal end). In a yet a further alternative, the automated stitching system may comprise a sewing machine. The automated wire system may be configured to guide the sewing needle and the threaded conductive wire multiple times through a flange of the package of the radio module so as to form a plurality of stitches. The stitched / sewn conductive wire may travel around the flange so as to form a substantially circular (or elliptical) shape. Each of the one or more articulating members may be, for example, a (programmable) articular robotic arm. The one or more articulating members (or at least one of them) may be configured to be maneuverable around a pre-defined location. The operation of the automated wire stitching or sewing system may be controlled, e.g., by a dedicated control computing device or a central control computing device of the manufacturing system. In some other examples, manual stitching may be carried out.

[0112] In some examples, a single central control computing device may be provided for controlling, e.g. a pick-and-place process as well as the process of arranging (e.g., winding, knotting or stitching) the conductive wire around the package of the radio module. Said central control computer or unit may comprise at least one processor and at least one memory storing instructions that, when executed by the at least one processor, may cause the apparatus at least to cause the performing of actions pertaining to the method 2000. The central computing device is discussed in further detail in connection with Figure 12.

[0113] In some examples, the method shown in Figure 8 may be carried out for a plurality of radio modules. In such examples, the process of moving from processing a first radio module to processing a second radio module should be as seamless as possible. Figure 9 illustrates an example of a method 3000 of manufacturing an RFID tag according to examples for expediting and automating the serial manufacturing process using an (automated) wire reeling system. A first end of the conductive wire may be wound around a supply reel of such wire reeling system and a second end of the conductive wire may be wound around a take-up reel of the wire reeling system.

[0114] In the example method 3000, a plurality of radio modules for different RFID tags may be provided in block 3100. The radio modules may be assumed to be initially arranged in a pre-defined (source) location. Subsequently, a first radio module may be picked in block 3200 and placed at a pre-defined location in block 3300. Once in the pre-defined location, a section of the conductive wire may be arranged around the package in block 3400. Finally, following the arranging of the section of the conductive wire, the conductive wire may be reeled, using the wire reeling system, in block 3500. The conductive wire may be reeled from the supply reel to the take-up reel so as to move the radio module towards the take-up reel. The reeling may be achieved by rotating the take-up reel.

[0115] Thereafter, the blocks 3200 to 3500 may be repeated for the next radio module of the plurality of radio modules. In other words, the picking and placing of the radio module and the mounting (e.g., winding, knotting or stitching) of the conductive wire around the package may be carried out during a pre-defined pause in the reeling (so-called stop-and-go manufacturing). As the process may be carried out for the plurality of radio modules in turns, the plurality of radio modules with the conductive wire arranged (e.g., wound, knotted, or stitched) around them may be collected to the take-up reel. In this manner, a wire reel, having conductive wire wound thereon, said wound conductive wire holding a plurality of radio modules, may be obtained so as to form a plurality of RFID tags.

[0116] A pre-defined level of tension may be maintained in the conductive wire during the arranging (e.g., winding or knotting) of the conductive wire around the radio module in block 3400 so as to enable efficient operation.

[0117] In addition to the supply and take-up reels, the wire reeling system may further comprise one or more (or all) of the following elements.

[0118] The wire reeling system may comprise a reel drive motor configured to power the reeling operation (that is, powering rotation of the take-up reel to enable reeling). Moreover, the wire reeling system may comprise a motor drive (e.g., a variable frequency drive or an inverted drive) configured to enable precise control of the reel drive motor (e.g., speed of reeling). To enable evaluating the current reeling speed of the conductive wire during reeling, the wire reeling system may comprise one or more speed sensors arranged along the length of the conductive wire or at the source and / or take-up reel. The motor drive may be controllable by the central computing device of the manufacturing system. In some examples, the wire reeling system may comprise at least the supply and take-up reels, the reel drive motor, the motor drive and the one or more speed sensors.

[0119] The wire reeling system may comprise a tension control system configured to maintain a consistent and controlled tension on the conductive wire as it is pulled by the supply reel. The tension control system may be connected to the motor drive for changing the speed of the reeling so as to increase or decrease tension in the conductive wire. To enable evaluating the current tension in the conductive wire during reeling, the wire reeling system may comprise a control computing device and one or more tension sensors arranged along the (non-reeled) length of the conductive wire and communicatively connected to the control computing device. If the control computing device of the tension control system detects via measurements of the one or more tension sensors that the measured tension is beyond predefined desired limits, the control computing device may trigger the motor drive to adjust the speed of the reeling accordingly to address the problem. In examples, the actions described above as being carried out by the control computing device of the tension control system may be carried out instead by the central control computing device of the manufacturing system (and thus no dedicated control computing device for tension control needs to be provided).

[0120] The wire reeling system may comprise wire guides (e.g., one or more supports and / or one or more rollers and / or one or more pulleys) for guiding the conductive wire from the supply reel to the take-up reel. The wire guides may also be employed for arranging the wire so that the conductive wire and the radio module placed at a pre-defined target location are arranged along the same plane (being, e.g., a horizontal plane). In some examples, at least some of the wire guides may be adjustable. To this end, the wire reeling system may also comprise one or more alignment sensors for measuring alignment of the conductive wire (especially in relation to the pre-defined location to which the radio modules are arranged for the wire arrangement operation). If any of the one or more alignment sensors detects misalignment of the conductive wire, it triggers adjustment of the wire guidance means to correct the positioning of the metallic wire.

[0121] In some examples, the automated wire mounting system may comprise a control computer configured to control the process of arranging (e.g., winding, knotting or stitching) the conductive wire around the package of the radio module. The control computer may be further configured to control to the (automated) wire reeling system.

[0122] In some examples, similar to as described above, a single central control computing device may be provided for controlling the pick-and-place process, the process of arranging (e.g., winding, knotting or stitching) the conductive wire around the package of the radio module as well as the reeling process (or at least some aspects thereof), that is, for controlling theautomated picking and placing system, the automated wire mounting system and the wire reeling system.

[0123] In some examples, the methods 2000, 3000 of Figures 8 and / or 9 may further comprise a step of applying an adhesive on the package of the radio module and / or on the section of the conductive wire so as to improve the mechanical fixation of the section of the conductive wire to the package of the radio module. The use of adhesive may be particularly useful when using winding for the arrangement of the section of conductive wire. Thus, a more secure connection may be obtained when using knotting or stitching.

[0124] Specifically, the adhesive may be applied on the surface of the package (that is, to a part of the surface of the package against which the conductive wire is to be arranged) before and / or during the arranging of the section of the conductive wire around the package. Alternatively, or additionally, the adhesive may be applied on the section of the conductive wire during the arranging of the section of the conductive wire around the package, before and / or after the section of the conductive wire has been arranged in contact with the radio module. The adhesive may be applied, for example, manually (i.e. , by a human) or using an automatic syringe (or infusion pump) supported by a robotic arm.

[0125] Figures 10A, 10B and 10C illustrate three consecutive phases of a method of (serial) manufacturing RFID tags according to some examples.

[0126] The manufacturing system of Figures 10A, 10B and 10C comprises a supply reel 501 for holding a first end of a conductive wire, a take-up reel 502 for holding a second end of a conductive wire acting as a take-up reel, an automated picking and placing system 503 (e.g., a pick-and-place machine) with a picking / placing arm 504, a set of radio modules 505 arranged in a pre-defined source location and a cylindrical winding tool 506 through which the conductive wire travels and which is rotatable around a pre-defined target location. The cylindrical winding tool 506 has a shape of a hollow right cylinder. The cylindrical winding tool 506 may be attached to a rotating member (e.g., to its end). The rotating member may be a robotic arm such as an articulated robotic arm, a non-articular robotic arm or a selective compliance assembly robot arm (SCARA). The manufacturing system further comprises a wire reeling system (not shown). Figures 10A, 10B and 10C illustrate specifically the winding process for a particular radio module 507. In general, the radio modules may be defined as described in connection with previous examples.

[0127] Figure 10A illustrates a midpoint of a serial manufacturing process. In said midpoint, conductive wire has been already wound around a plurality of radio modules and said woundradio modules have been reeled to the second reel 502. In Figure 10A, the winding has been carried out for a radio module 508 and the conductive wire has been reeled to move said wound radio module 508 away from a pre-defined target location of the automated picking and placing system 503, as illustrated by an arrow indicating rotation of the take-up reel 502. The automated picking and placing systems are ready to pick up and place the next radio module 507. Thus, the state shown in Figure 10A may correspond to the state between blocks 3500 and 3200 in Figure 9.

[0128] In Figure 10B, the radio module 507 has just been picked up and placed, by the picking and placing system 503, to a pre-defined target location for winding. The conductive wire has not yet been wound around the package of the radio module. Thus, the state shown in Figure 10B corresponds to the state between blocks 3300 and 3400 in Figure 9.

[0129] In Figure 10C, the conductive wire is being wound, for one or more turns around the package of the radio module 507. In this example, the winding may be achieved by rotating the cylindrical winding tool 506 around the radio module 507 arranged at a pre-defined target location. The relatively long cylindrical shape of the cylindrical winding tool 506 serves to restrict the movement of the conductive wire while it is being rotated around the radio module 507. The cylindrical winding tool 506 may be moved (slightly) in a direction orthogonal to the rotation plane during the winding or upon completion of each full rotation so that the individual windings or loops of the conductive wire around the radio module 507 do not overlap with each other but are adjacent to each other. As described above, in some examples, a gripping element or tool may be employed instead of an element with a hole. Thus, the state shown in Figure 10C corresponds to block 3400 of Figure 9. Figure 10C further shows a tool 509 (e.g., an automatic syringe) for applying an adhesive on the wound section of the conductive wire once the winding has finished.

[0130] Figures 11 A, 11 B, 11C and 11 D illustrate four consecutive phases of a method of (serial) manufacturing RFID tags according to some additional examples. Specifically, Figures 11 A, 11 B, 11C and 11 D illustrate the execution of the process of Figure 9 where conductive wire is knotted around radio modules by forming a clove hitch knot as discussed in connection with Figures 5 and 6.

[0131] The manufacturing system of Figures 11 A, 11 B, 11C and 11 D comprises a supply reel 901 for holding a first end of a conductive wire, a take-up reel 902 for holding a second end of a conductive wire acting as a take-up reel, an automated picking and placing system 903 (e.g., a pick-and-place machine) with a picking / placing arm 904, a set of radio modules 905 arranged in a pre-defined source location, an articulating (robotic) member (e.g., aprogrammable robotic arm) comprising (e.g., at its distal end) gripping element or tool 906 (e.g., tweezers) for gripping the conductive wire while the knot is being formed and two rollers 909, 910 for guiding and facilitating maintaining tension of the conductive wire. The articulating member may be an articulated robotic arm. The articulating member and its gripping element or tool 906 may be controllable by a dedicated or central control computer. The manufacturing system further comprises a wire reeling system (not shown). Figures 11 A, 11 B, 11C and 11 D illustrate specifically the winding process for a particular radio module 907. In general, the radio modules may be defined as described in connection with previous examples.

[0132] In examples, the two rollers 909, 910 may be omitted or replaced with one or more guides and / or rollers.

[0133] In examples, the manufacturing system may comprise a plurality of articulating members (e.g., programmable robotic arms) comprising each, at their distal ends, a gripping element or tool (e.g., tweezers). The plurality of articulating members may all take part in forming the knot (e.g., the clove hitch knot).

[0134] Figure 11A illustrates a midpoint of a serial manufacturing process. In said midpoint, conductive wire has been already knotted around a plurality of radio modules and said wound radio modules have been reeled to the second reel 902 (as visible in the take-up reel 902 though not in proportion). In Figure 11A, the knotting has been carried out for a radio module 908 and the conductive wire has been reeled to move said wound radio module 908 away from a pre-defined target location of the automated picking and placing system 903, as illustrated by an arrow indicating rotation of the take-up reel 902. The automated picking and placing systems are ready to pick up and place the next radio module 907. Thus, the state shown in Figure 11A corresponds to the state between blocks 3500 and 3200 in Figure 9.

[0135] In Figure 11 B, the radio module 907 has just been picked up and is in the process of being placed, by the picking and placing system 903, to a pre-defined target location for knotting. Thus, the state shown in Figure 11 B corresponds to the state of block 3300 in Figure 9.

[0136] In Figure 11 C, the pick-and-place machine 903 has placed the radio module 907 to the pre-defined target location, and the conductive wire is being gripped and knotted around the package of the radio module 907. Here, the conductive wire running between the two rollers 909, 910 and the radio module placed to the pre-defined target location may be assumed to be arranged along the same plane (being, e.g., a horizontal plane). Specifically, Figure 11C illustrates the first stage of forming a clove hitch knot, that is, the step 801 of Figure 6. Thus,the articulating member is controlled to grip the conductive wire using the gripping element 906 and to wrap the conductive wire around the radio module 507 as shown in the step 801 of Figure 6. Thus, the state shown in Figure 11C corresponds to a first part of block 3400 of Figure 9.

[0137] Figure 11 D shows the second stage of forming the clove hitch knot, that is, the steps 802, 803 of Figure 6. Thus, the articulating member is controlled to grip the conductive wire using the gripping element 906 and to wrap the conductive wire again around the radio module 507.

[0138] Compared to the winding alternative discussed in connection with Figures 10A - 10C, the knotting alternative as described in connection with Figures 11A-11 D may provide the benefit that the formed knot serves to secure the conductive wire more tightly and strongly around the radio module compared to simply winding the conductive wire around the radio module. Thus, while use of any adhesive for fixing the conductive wire to the radio module is possible also in connection with the knotting-based examples, the benefit derived from the use of adhesive is smaller in these examples.

[0139] While the process of Figures 11A-11 D was discussed above specifically for knotting a section of the conductive wire around the radio module, it should be understood that a similar methodology may be employed also for winding the section of the conductive wire around the radio module for one or more turns or for stitching the section of the conductive wire. By means of these methods, multiple radio modules may be wound at intervals equal to the length of the antenna. In an example, such length may be of approximately 15 cm.

[0140] According to an example, there is provided a wire reel having conductive wire wound thereon, said wound conductive wire being arranged around and holding a plurality of radio modules so as to form a plurality of RFID tags according to any of the examples discussed above. Said wire reel may correspond, e.g., to the take-up reel 502 of Figure 10A-10C or the take-up reel 902 of Figures 11A-11 D following the completion of the serial winding / knotting process for the plurality of radio modules 505 / 905. The individual RFID tags may be produced simply by unwinding the wire reel and cutting a section out of the conductive wire.

[0141] In some examples, the RFID tag according to any of the examples discussed above may be attached or fixed (e.g., using an adhesive or using mechanical fastener(s)) to a substrate. Said substrate may be a textile, paper, or plastic substrate. Said substrate may be a flexible substrate. In other examples, the RFID tag may comprise no substrate fixed to the radio module.

[0142] In some examples, there is provided a textile item comprising the RFID tag according to any of the examples described above. The RFID tag is attached (e.g., sewn, woven, glued or hanged using cord or string) to textile material of the textile item. The textile item may be any item or object made fully or at least in part of textile material. The textile item may be, for example, a piece of clothing, a piece of linen, a towel, a piece of bedding, a piece of furniture, a carpet, a rug, a bag, a toy, or a tent or a sleeping bag. In some such examples, an additional coating (e.g., a polymer coating) or covering (e.g., a textile covering) may be provided around the RFID tag for improving its robustness and durability.

[0143] In some examples, an RFID tag according to any of the examples discussed above is used for tracking of a textile item during its lifetime. The lifetime of the textile item may be assumed to comprise multiple instances of washing of the item (e.g., in a commercial or industrial washing machine). As the RFID tag according to examples does not rely on a vulnerable physical connection between the IC and the antenna, it is especially well-suited for these types of applications.

[0144] Figure 12 provides an apparatus 1201 according to some examples. Specifically, Figure 12 may illustrate an apparatus 1201 for controlling a serial manufacturing process for manufacturing RFID tags according to examples. The apparatus 1201 may be a computing device or specifically a central control computer of the serial manufacturing process as described in above examples.

[0145] The apparatus 1201 may comprise one or more communication control circuitry 1220, such as at least one processor, and at least one memory 1230, including one or more algorithms 1231 (instructions), such as a computer program code (software) wherein the at least one memory 1230 and the computer program code (software) are configured, with the at least one processor, to cause the apparatus 1201 to carry out any one of the exemplified functionalities of the central control computer described above. Said at least one memory 1230 may also comprise at least one database 1232. In particular, sensors may be provided and the apparatus 1201 may be configured to continually monitor and adjusts different parameters such as tension, alignment or speed of the wire mounting process. Furthermore, in examples comprising winding of the conductive wire, the number of turns and the spacing between turns may also be monitored and controlled.

[0146] When the one or more communication control circuitry 1220 comprises more than one processor, the apparatus 1201 may be a distributed device wherein processing of tasks takes place in more than one physical unit. Each of the at least one processor may comprise one or more processor cores. A processing core may comprise, for example, a Cortex-A8processing core manufactured by ARM Holdings or a Zen processing core designed by Advanced Micro Devices Corporation. The one or more communication control circuitry 1220 may comprise at least one Qualcomm Snapdragon and / or Intel Atom processor. The one or more communication control circuitry 1220 may comprise at least one application-specific integrated circuit (ASIC). The one or more control circuitry 1220 may comprise at least one field-programmable gate array (FPGA).

[0147] Referring to Figure 12, the one or more communication control circuitry 1220 of the apparatus 1201 may be configured to cause operation according to example methods describe above using one or more individual circuitries. It is also feasible to use specific integrated circuits, such as ASIC or other components and devices for implementing the functionalities in accordance with different examples.

[0148] Referring to Figure 12, the apparatus 1201 may further comprise different interfaces (l / F) 1210 such as one or more communication interfaces comprising hardware and / or software for realizing communication connectivity according to one or more communication protocols. The one or more communication interfaces 1210 may comprise, communication interfaces between the apparatus 1201 and a plurality of actuators (e.g., devices) of the serial manufacturing system. The actuators comprise at least an (automated) picking and placing system (e.g., a pick-and-place machine) and (automated) wire mounting systems (e.g., wire winding systems or wire knotting systems). The actuators may further comprise a wire reeling system (e.g., a motor drive and / or a tension control system thereof) and / or an applicator for applying an adhesive on the radio module and / or on the section of the conductive wire arranged around a radio module.

[0149] The one or more communication interfaces 1210 may comprise standard components such as an amplifier, filter, frequency-converter, (de)modulator, and encoder / decoder circuitries, controlled by the corresponding controlling units, and one or more antennas. The apparatus 1201 may also comprise one or more user interfaces.

[0150] If the apparatus 1201 is a terminal device, the apparatus 1201 may comprise one or more user input devices and / or interfaces for connecting one or more user input devices.

[0151] Referring to Figure 12, the memory 1230 may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory.

[0152] As used in this application, the term ‘circuitry’ may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and / or digital circuitry, and (b) combinations of hardware circuits and software (and / or firmware), such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software, including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus, such as a terminal device or an access node, to perform various functions, and (c) hardware circuit(s) and processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g. firmware) for operation, but the software may not be present when it is not needed for operation. This definition of ‘circuitry’ applies to all uses of this term in this application, including any claims. As a further example, as used in this application, the term ‘circuitry’ also covers an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware.

[0153] In an example, at least some of the processes described in connection with Figures 8,9, 10 or 11 may be caused (or triggered) to be carried out by an apparatus (e.g., a central control computing device) comprising corresponding means for carrying out at least some of the described processes. Some example means for carrying out the processes may include at least one of the following: detector, processor (including dual-core and multiple-core processors), digital signal processor, controller, receiver, transmitter, encoder, decoder, memory, RAM, ROM, software, firmware, display, user interface, display circuitry, user interface circuitry, user interface software, display software, circuit, filter (low-pass, high-pass, bandpass and / or bandstop), sensor, circuitry, inverter, capacitor, inductor, resistor, operational amplifier, diode and transistor. In an example, the at least one processor, the memory, and the computer program code form processing means or comprises one or more computer program code portions for carrying out (or causing carrying out of) one or more operations according to any one of the examples described above or operations thereof. In some examples, at least some of the processes may be implemented using discrete components.

[0154] Examples as described may also be carried out, fully or at least in part, in the form of a computer process defined by a computer program or portions thereof. Examples of the methods described above may be carried out by executing at least one portion of a computer program comprising corresponding instructions. The computer program may be provided as a computer readable medium comprising program instructions stored thereon or as a non- transitory computer readable medium comprising program instructions stored thereon. The computer program may be in source code form, object code form, or in some intermediateform, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. For example, the computer program may be stored on a computer program distribution medium readable by a computer or a processor. The computer program medium may be, for example but not limited to, a record medium, computer memory, readonly memory, electrical carrier signal, telecommunications signal, and software distribution package, for example. The computer program medium may be a non-transitory medium. Coding of software for carrying out the examples as shown and described is well within the scope of a person of ordinary skill in the art.

[0155] The term “non-transitory”, as used herein, is a limitation of the medium itself (that is, tangible, not a signal) as opposed to a limitation on data storage persistency (for example, RAM vs. ROM).

[0156] Figure 13 illustrates a method of manufacturing the IC of the RFID tag according to any of the examples described above. In this example, the IC comprises an integrated (or on- chip) inductive element. Any of the definitions provided above for the IC of the RFID tag apply, mutatis mutandis, also here.

[0157] Block 1301 : A semiconductor substrate (or a semiconductor wafer) is provided. The semiconductor substrate may be, for example, a silicon substrate. It is also assumed that the layout of the IC to be manufactured (i.e. , the IC according to any of the examples discussed above) is known at this point. Thus, the IC to be manufactured is assumed to comprise RFID circuitry and an integrated inductive element configured to inductively couple the RFID circuitry wirelessly to at least one antenna of the RFID tag.

[0158] Block 1302: Front-end-of-line (FEOL) processing is performed for the semiconductor substrate according to a pre-defined layout of integrated circuit. The FEOL is the first part of IC fabrication where the individual components (e.g., transistors, capacitors, inductors and resistors, memory cells) are patterned in the semiconductor. The FEOL processing may cover all manufacturing steps up to (but not including) the deposition of metal interconnect layers.

[0159] In some examples, the FEOL processing of block 1302 may comprise all or at least some of photolithography, etching, doping, annealing and layer forming (e.g., deposition) and patterning processes which are described in further detail in the following. Optionally, the FEOL processing of block 1302 may also comprise planarization and / or cleaning processes.

[0160] Photolithography and etching processes may be carried out on the semiconductor substrate according to a pre-defined layout of the IC for defining features (e.g., electrical components) of the IC as a part of block 1302. The photolithography and etching processesmay comprise, e.g., applying a photoresist on the semiconductor substrate, projecting a mask pattern onto the photoresist using ultraviolet light, developing the photoresist and etching remove material from the surface of the semiconductor substrate based on the mask pattern defined by the photoresist. The etching may be wet or dry etching. The photolithography & etching step may be used specifically for forming and patterning the main IC features (excluding any possible interconnect layers which are manufactured in block 1303). Optionally, additional chemical mechanical planarization, cleaning and / or annealing steps may be performed.

[0161] Pre-defined regions of the semiconductor substrate may be doped and optionally annealed according to the pre-defined layout of the RFID circuitry as a part of block 1302. This way, desired electrical properties for the electrical components (e.g., source and drain regions of transistors) and memory elements may be implemented. In doping, dopants (i.e. , impurity atoms, electrostatic dopants, chemical dopants) are introduced into the semiconductor material through ion implantation, diffusion or deposition. The semiconductor substrate maybe subjected to high-temperature annealing processes to activate dopants and repair defects introduced during the previous steps.

[0162] Conductive layers and insulating layers associated with the conductive layers may be formed (e.g., deposited) and patterned onto the semiconductor substrate according to the pre-defined layout of the IC so as to form components of the RFID circuitry. This step may comprise, for example, gate formation (or equally gate deposition), source and drain formation (or equally source and drain deposition), gate oxide formation (or equally gate oxide deposition), silicidation (optional), insulating spacer formation (optional), forming opening for electrical contacts and building conductive wiring for connecting the electrical components. Additionally or alternatively, deposition processes employed may comprise deposition of conductors, barriers and dielectric materials, e.g. using physical vapor deposition (PVD) and / or chemical vapor deposition methods (CVD).

[0163] Block 1303: Back-end-of-line (BEOL) processing is performed for the semiconductor substrate according to the pre-defined layout of integrated circuit. In general, the BEOL processing is the second portion of IC fabrication where the individual devices (e.g., transistors, capacitors or resistors) are interconnected on the semiconductor substrate via conductive layers (being, e.g., metal, bimetallic alloy, organic or inorganic conductor layers). Here, the performing of the back-end-of-line processing in block 1303 comprises, in addition to the conventional forming and patterning of conductive interconnect layers of the IC (or the RFID circuitry thereof), forming and patterning the integrated inductive element (e.g., a planar spiralinductor). As mentioned above, implementing the integrated inductive element as part of the BEOL processing step, as opposed to attaching it to the IC following the integrated manufacturing of the IC, provides multiple benefits. Namely, the manufacturing process of the IC and consequently of the RFID tag is simplified. It also enables improving of the production reliability by enabling relaxing the accuracy, time and cost requirements for accurately positioning the IC.

[0164] In the BEOL processing of block 1303, conductive layers and insulating layers associated with (and adjacent to) the conductive layers are formed and patterned onto the semiconductor substrate according to the pre-defined layout of the integrated circuit. The conductive layers comprise at least interconnect layers of the IC (or at least of the RFID circuitry of the IC) and conductive layer(s) forming an integrated inductive element of the integrated circuit electrically connected to the RFID circuitry. In other words, the new integrated inductive element of the IC is manufactured as a part of the BEOL manufacturing stage (equally called conductive interconnect manufacturing stage) of the IC fabrication flow. As described above, the integrated inductive element is configured and arranged here to enable inductive coupling of the RFID circuitry wirelessly to at least one antenna of the RFID tag. Last (or topmost) of the conductive (interconnect) layers may be considered best suited for implementation of the integrated inductive element as this enables reduction of the number of interconnect steps. The conductive layers may be, e.g., copper, aluminum or silver layers and / or the insulating layers may comprise, e.g., one or more silicon dioxide layers and / or one or more polyimide layers. Said conductive layers may be formed and patterned, e.g., using chemical vapor deposition (CVD) or physical vapor deposition (PVD) followed by photolithography and etching processes. The insulating layers may be formed, e.g., using plasma-enhanced chemical vapor deposition (PECVD) (e.g., for silicon dioxide layers) or by spin coating (e.g., for polyimide layers). These processes are repeated for each successive conductive / insulating layer until all the layers defined in the pre-defined layout of the IC are completed.

[0165] In some examples, additional interconnect steps specifically for the fabrication of the integrated inductive element can be introduced by additional process repetition steps if desired or needed to accommodate for space related constraints arising from dense interconnect patterning.

[0166] Between the forming and patterning of the conductive & insulating layers in block 1303, conductive vias for connecting the conductive layers together in a desired manner are formed according to the pre-defined layout of the integrated circuit. The via(s) of a given layermay be formed, e.g., by performing photolithography to define the locations of the via(s), etching to create via hole(s) and filling those via hole(s) with a conductive material. Said conductive material may be, e.g., a metal, a conductive oxide or an organic conductive material. For example, said conductive material may be titanium, titanium nitride, tungsten, aluminum, copper or carbon. One or more conductive vias may be implemented at least for implementing an input port of the integrated inductive element for enabling connecting the RFID circuitry to the integrated inductive element, as described in connection with Figure 1 B.

[0167] It should be noted that the manufacturing method of Figure 13 may be also altered in various ways to accommodate different variations. One of the variations relating specifically to block 1303 comprises performing, first, dielectric deposition (e.g., deposition of SiO2 or polyimide) and then patterning trenches for metal deposition by means of lithography and dielectric etching. The trenches are then filled with deposition of conductive material such as copper by means of PVD, OVD or electrodeposition. Excess conductive material may be removed by means of mechanical and chemical polishing and planarization of the surface. Subsequent dielectric deposition and conductive via formation can be carried out as described.

[0168] In some examples, one or more of the following additional steps may be carried out as a part of the BEOL processing of block 1302 and / or after block 1303 as a part of a back- end (or post-fab) process:

[0169] employing chemical-mechanical polishing (CMP) processes to planarize the surface of the semiconductor substrate (may be performed alternatively between blocks 1304, 1305), and / or

[0170] applying a passivation layer on the semiconductor substrate for protection against environmental factors and physical damage, and / or

[0171] performing electrical testing, functional testing and / or reliability testing on the manufactured IC to verify compliance with predetermined performance and quality standards, and / or

[0172] packaging (and encapsulating) the manufactured IC for integration into the RFID tag

[0173] In some examples, at least the chemical-mechanical polishing (CMP) processes may be performed. The CMP may be performed, for each conductive layer for which via(s) are needed, after the completion of the conductive layer or after the completion of the forming of via(s) associated with said conductive layer.

[0174] In some examples, at least the packaging (and encapsulating) step of the above listed additional steps may be performed. It should be noted that, with the IC design according to examples, it is not necessary to leave any conductive or active part exposed (i.e. , left outside of the IC package) in contrast with conventional ICs where a pad for antenna contact must be left exposed. Thus, the full packaging of the IC provides superior environmental robustness.

[0175] Figure 14 shows the results of an experimental test carried out to compare the performance of an RFID tag according to an example of the disclosure and a reference RFID tag. In particular, the read range, in meters, as a function of frequency, in megahertz, is used as the parameter for the comparison. The RFID tag according to the disclosure corresponds to an example where the conductive wire is wound for two turns around the radio module comprising an integrated circuit (with an on-chip inductive element), that is, the RFID tag substantially corresponds to the example shown in Figures 3A and 3B though with a different number of windings and different dimensions. As far as the reference RFID tag is concerned, a HID® LinTRAK® C15H-M730 tag was selected.

[0176] It is important to note that the exact same conductive wires and IC were used to enable a proper comparison. Accordingly, the only significant technical difference lies in the arrangement of the conductive wire with respect to the IC which affects the inductive coupling between the antenna of the RFID tag and the inductive element.

[0177] As seen in Figure 14, the RFID tag according to the disclosure clearly outperforms the reference RFID tag in almost all of the shown frequencies. Within the European Union frequency band 866 MHz - 869 MHz and / or the United States frequency band 902 MHz - 928 MHz, performance of the RFID tag according to the example at least doubles the theoretical read range compared to the reference RFID tag (i.e., 16-17 meters versus 7-8 meters).

[0178] The theoretical read range of RFID tags can be derived from the following equation: IGT. EIRP. T RR = — H— -471 J Pth

[0179] where is the wavelength of the radiofrequency, GTis power gain of the RFID tag, EIRP is the effective isotropic radiated power, T is the transmission coefficient, and Pthis the activation power of the IC.

[0180] Considering A. = c / f, for a given wavelength A, the only variable term in the equation is the transmission coefficient (i.e., GT, EIRP, and Pthare all constants for a given IC and antenna).

[0181] In some designs, the radio module or, more particularly, the package, may be placed substantially at the center of the antenna. Specifically, the radio module may be placed at the center of the longitudinal direction of the antenna, i.e. the direction defining the largest dimension or span of the antenna. Nevertheless, it has been found that, by placing the package asymmetrically relative to the antenna, the transmission coefficient for the European range of operation (between 866 and 869 MHz) and / or for the American range (between 902 and 928 MHz) may be maximized. Consequently, the read range in the European range and / or the American range may also be improved.

[0182] Indeed, a radio frequency identification, RFID, tag may comprise a radio module comprising an integrated circuit comprising RFID circuitry. The radio module may further comprise an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag. Furthermore, the radio module may comprise a package, configured to encapsulate, at least in part, the integrated circuit and the inductive element. The RFID tag may further comprise a conductive wire, configured to act as the antenna of the RFID tag. The conductive wire may comprise a section arranged substantially around the radio module. The antenna may comprise a longitudinal direction, i.e. a direction exhibiting maximum span or extension of the antenna. A plane may be defined, perpendicular to such longitudinal direction and located substantially aligned with the radio module. The arrangement of the conductive wire with respect to the radio module may be asymmetrical with respect to such plane.

[0183] In other words, the conductive wire may be disposed such that, when taking into account a longitudinal direction of the antenna, a different distance is defined between the radio module and the most distal portions of the conductive wire in different senses along such longitudinal direction.

[0184] Figure 15 schematically shows an RFID tag 1200 with such an asymmetrical arrangement. Figure 15 shows the results of an experimental test carried out to compare the performance of an RFID tag according to an example of the disclosure and a symmetrical RFID tag. As far as the reference RFID tag is concerned, a HID® LinTRAK® C15H-M730 tag was selected. In this example, the RFID tag 1200 may comprise a radio module comprising an integrated circuit comprising RFID circuitry and an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag 1200. The radio module may also comprise a package 1205 to encapsulate, at least in part, the integrated circuit and the inductive element. The RFID tag 1200 may also comprise a conductive wire 1203, configured to act as the antenna of the RFID tag 1200. The conductive wire 1203 may comprise a section 1204 arranged substantially around the radio module. Moreover, the antenna may be alignedwith a longitudinal direction 1250, i.e. a direction exhibiting a maximum extension of the antenna. In Figure 15, the longitudinal direction 1250 is a substantially horizontal direction. A plane 1255 may be defined, perpendicular to the longitudinal direction 1250 and substantially aligned with a center of the radio module, i.e. with the corresponding package 1205 of the radio module. The conductive wire 1203 may be arranged asymmetrical with respect to such plane 1255.

[0185] In some other examples, the package 1205 may incorporate some form of physical asymmetry and / or the internal inductive element may be arranged in an asymmetric manner with respect to the package 1205. Accordingly, in such examples, an asymmetrical arrangement of the conductive wire 1203 with respect to the inductive element of the radio module may be provided by arranging the conductive wire 1203 asymmetrically with respect to a plane perpendicular to the longitudinal direction of the antenna and centered substantially with the inductive element of the radio module. In these examples, the plane may not coincide with the center of the package 1205.

[0186] In the example shown in Figure 15, the conducive wire 1203 comprises two end sections 1209, 1210 extending in the longitudinal direction of the antenna, i.e. in the horizontal direction. As shown in the figure, the length of a first section 1209 may be shorter than the length of a second section 1210 extending in the opposite sense. In this manner, an asymmetrical arrangement with respect to the plane 1255, which perpendicular to the longitudinal direction 1250 and substantially aligned with the package 1205, may be obtained. Such arrangement results in enhanced read range for the RFID tag 1200.

[0187] Figure 16 provides a measured comparison for the read range obtained for different RFID tags designed with an arrangement substantially like the one in Figure 15. In particular, an antenna with end sections 1209, 12010 extending for a total length of 15 cm is considered in all cases. Figure 16 illustrates the read range as a function of the frequency of the radiofrequency signal for four different configurations: line 1251 is used as a baseline as it corresponds to the symmetric arrangement in which the length of both sections 1209, 1210 is equal to 7.5 cm. Line 1252 corresponds to an arrangement wherein the length of one of the two sections 1210 is equal to 9 cm whereas the other section 1209 has a length of 6 cm. The behavior of a more asymmetric arrangement is illustrated in line 1253, which corresponds to a length of 9.5 cm and 5.5 cm for each of the corresponding sections 1209, 1210. Finally, line 1254 illustrates the most asymmetric arrangement which, in this example, corresponds to lengths of 10 cm and 5 cm.

[0188] As shown in Figure 16, an improved read range may be obtained by properly adjusting the degree of asymmetry. Thus, in the configuration depicted in Figure 16, an enhanced performance relative to the symmetric case 1251 is achieved for frequencies in the range from 865 MHz to 915Hz, which, as indicated above, include the relevant ranges for RFID application in Europe and United States) for moderate asymmetries. In particular, line 1252, corresponding to an asymmetry of 9 cm and 6 cm, shows increased read range which, in the case of the particular configuration used in the example, results in an improvement of about 7% for the European frequency range (from about 16.5 meters to 17.6 meters on average).

[0189] It may be understood that, depending on the desired form factor of the antenna, the arrangement or the positioning of the radio module relative to the antenna may vary.

[0190] In the example depicted in Figure 15, the RFID tag 1200 is such that the section 1204 of the conductive wire 1203 arranged substantially around the radio module is supported by the package 1205 of the radio module. The section 1204 of the conductive wire 1203 supported by the package 1205 of the radio module may comprise one or more turns.

[0191] It is understood that the asymmetric arrangement, schematically illustrated in Figure 15, may be applied to any of the different examples described in relation to Figures 3-7. Thus, the section 1204 may be wound, knotted or stitched on the package 1205. Corresponding end sections may then be arranged asymmetrically, i.e. with different length for each of the two sections.

[0192] In still further examples, the conductive wire and the radio module may be individually fixed onto a substrate. On the one hand, the conductive wire may be fixed to the substrate by means of a retention element, such as a thread sewing the conductive wire to the substrate. On the other hand, the radio module may be fixed to the substrate by gluing, sewing or by inserting it in a pouch type enclosure built in the substrate. In all cases, the conductive wire may be fixed such that an asymmetrical arrangement arises, i.e. similarly to Figure 15, a distance from the radio module to respective ends of the conductive wire in the longitudinal direction of the antenna may be different. Furthermore, as already explained with reference to Figure 15, the precise arrangement of the radio module and, consequently, the precise degree of asymmetry may depend on each specific design and application.

[0193] A method for manufacturing an RFID tag with an asymmetric arrangement of the antenna may be provided. The method may comprise providing a radio module, the radio module comprising an integrated circuit, comprising RFID circuitry. The radio module may further comprise an inductive element configured to enable inductive coupling of the RFIDcircuitry. Moreover, the radio module may comprise a package configured to encapsulate, at least in part, the integrated circuit and the inductive element. The method may further comprise arranging a section of a conductive wire substantially around the radio module and arranging the conductive wire in an asymmetrical manner. As described above, arranging in an asymmetrical manner is to be understood as arranging the conductive wire and the radio module asymmetrically with respect to a plane perpendicular to the longitudinal direction of the antenna and substantially centered in the package of the radio module and / or in the inductive element contained within the radio module.

[0194] To this end, in an example, the section of the conductive wire may be supported by the package of the radio module by either winding, knotting or stitching.

[0195] In other examples, the method may further comprise providing a substrate. Both the radio module and the conductive wire may be individually fixed to the substrate. As an example, the conductive wire may be fixed to the substrate by sewing. Besides, the radio module may be fixed by gluing, sewing or by arranging the radio module in a pouch type enclosure built in the substrate.

[0196] Finally, it is worth noting that the method, systems and apparatus described in reference to Figures 10A-10C, 11A-11 D may also be used for RFID tags comprising an asymmetric arrangement of the antenna with respect to the radio module.

[0197] In some examples, the radio module may comprise a magnetically permeable material. In particular, in some variants, the package 605, 705, 1005, 1105, and 1205 may comprise a magnetically permeable material. The package 605, 705, 1005, 1105, and 1205 may be made of only one material being the magnetically permeable material, or it may comprise at least two different materials, one material being the magnetically permeable material. In the latter case, the package 605, 705, 1005, 1105, and 1205 may comprise a first region and a second region. The first region of the package 605, 705, 1005, 1105, and 1205 may comprise the magnetically permeable material. The second region of the package 605, 705, 1005, 1105, and 1205 may be made of the material that is different from the magnetically permeable material.

[0198] The material that is different from the magnetically permeable material may be a non-conductive material such as glass epoxy resin or polypropylene sulfide.

[0199] The magnetically permeable material may be a ferrite material selected from the following: ferrite Fe, manganese-zinc ferrite MnsZn(i-6) Fe2O4, nickel-zinc ferrite NisZn(i-6) Fe2O4, cobalt ferrite, strontium ferrite, barium ferrite, or combinations thereof.

[0200] The magnetically permeable material may have a relative permeability between 50 and 1000, specifically about 100, for improving the coupling between the RFID circuitry to the antenna of the RFID tag, in other words, for improving mutual inductance between the antenna and the inductive element is increased.

[0201] In some examples, the first region comprising the magnetically permeable material may extend beyond the section of the conductive wire supported by the package 605, 705, 1005, 1105, and 1205. By extending beyond the section of the conductive wire supported by the package 605, 705, 1005, 1105, and 1205, miscoupling of the RFID circuitry to the antenna due to magnetic field confinement may be avoided.

[0202] By encapsulating the integrated circuit and the inductive element at least partially, the distance between the antenna and the inductive element located inside the package is reduced. The size of the RFID circuitry and the corresponding inductive element to couple the RFID circuitry to the antenna can be further reduced by using a magnetically permeable for the package. As a result, the package and the magnetically permeable material may synergistically reduce the size of the RFID tag.

[0203] For reasons of completeness, various aspects of the present disclosure are set out in the following numbered clauses:Clause 1. A radio frequency identification, RFID, tag comprising: a radio module comprising an integrated circuit comprising RFID circuitry, an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element, a conductive wire, configured to act as the antenna of the RFID tag, comprising a section supported by the package of the radio module.Clause 2. The RFID tag of clause 1 , wherein the section of the conductive wire supported by the package of the radio module comprises one or more turns around the package.Clause 3. The RFID tag of clauses 1 or 2, wherein the section of the conductive wire is wound on a surface of the package of the radio module.Clause 4. The RFID tag of any previous clause, wherein a surface of the package comprises one or more grooves for positioning the conductive wire.Clause 5. The RFI D tag of clause 4, wherein the surface of the package comprises two grooves and the section of the conductive wire is wound along the two grooves so as to define two nonoverlapping turns.Clause 6. The RFID tag of clauses 1 or 2, wherein the section of conductive wire is knotted around a surface of the package.Clause 7. The RFID tag of clause 6, wherein the section of conductive wire is knotted with a clove hitch knot.Clause 8. The RFID tag of any previous clause, wherein the package comprises a first flange, a second flange, and a central portion arranged between the first flange and the second flange, the first flange and the second flange extending outwards from the central portion, and the section of conductive wire being supported by the central portion.Clause 9. The RFID tag of clauses 1 or 2, wherein the package comprises a plurality of holes and the section of conductive wire is stitched on the package via the holes.Clause 10. The RFID tag of clause 9, wherein the package comprises a center portion and a flange extending outwards from the center portion, the flange comprising the plurality of holes.Clause 11. The RFID tag of any previous clause, comprising a substrate fixed to the radio module.Clause 12. The RFID tag of any previous clause, wherein the conductive wire comprises an insulating outer layer.Clause 13. The RFID tag of any previous clause, wherein the inductive element is an integrated inductive element incorporated in the integrated circuit or wherein the inductive element is separate from the integrated circuit.Clause 14. The RFID tag of any previous clause, wherein the antenna of the RFID tag exhibits a longitudinal direction, and the conductive wire is arranged around the radio module in an asymmetrical manner relative to a plane, the plane being both perpendicular to the longitudinal direction of the antenna and substantially aligned with the radio module.Clause 15. The RFID tag of any previous clause, wherein the radio module comprises a magnetically permeable material.Clause 16. The RFID tag according to clause 16, wherein the magnetically permeable material comprises a ferrite material selected from the following: ferrite Fe, manganese-zinc ferrite Mn3Zn(i-s) Fe2O4, nickel-zinc ferrite NisZn(i-6) Fe2O4, cobalt ferrite, strontium ferrite, barium ferrite, or combinations thereof.Clause 17. The RFID tag according to clause 15 or clause 16, wherein the package of the radio module comprises the magnetically permeable material.Clause 18. The RFID tag according to clause 17, wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprising the magnetically permeable material.Clause 19. The RFID tag according to clause 17 or 18, wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprising the magnetically permeable material, wherein the first region extends beyond the section of the conductive wire supported by the package.Clause 20. A method of manufacturing a radio frequency identification, RFID, tag, the method comprising: providing a radio module for the RFID tag, wherein the radio module comprises an integrated circuit, comprising RFID circuitry, an inductive element configured to enable inductive coupling of the RFID circuitry, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element; and arranging a section of a conductive wire such that the section of the conductive wire is supported by the package.Clause 21. The method of clause 20, wherein arranging the section of the conductive wire comprises winding the conductive wire for one or more turns around a surface of the package.Clause 22. The method of clause 20, wherein arranging the section of the conductive wire comprises knotting the conductive wire around a surface of the package.Clause 23. The method of clauses 21 or 22, wherein the section of the conductive wire is adhesively mounted on the package.Clause 24. The method of clause 23, comprising applying an adhesive on the conductive wire for fixing the conductive wire to the package.Clause 25. The method of clauses 23 or 24, comprising applying an adhesive on a surface of the package for fixing the conductive wire to the package.Clause 26. The method of clause 20, wherein arranging the section of the conductive wire comprises stitching the section of conductive wire through a plurality of holes.Clause 27. The method of clause 26, wherein the method comprises stitching by puncturing the package during the stitching for creating the plurality of holes.Clause 28. The method of clause 26, wherein the method comprises providing a plurality of pre-prepared holes on the package before the stitching.Clause 29. The method of any of clauses 20 to 28, wherein a first end of the conductive wire is wound around a supply reel of a wire reeling system and a second end of the conductive wire is wound around a take-up reel of the wire reeling system, the method further comprising: following the arranging of the section of the conductive wire, reeling, using the wire reeling system, the conductive wire from the supply reel to the take-up reel so as to move the radio module towards the take-up reel.Clause 30. The method according to clause 29, further comprising: providing a second radio module for an RFID tag, and repeating the arranging of the section of the conductive wire and the reeling for the second radio module, wherein a different section of the same continuous conductive wire is arranged on the packages of the different radio modules.Clause 31 . The method according to any of clauses 20 to 30, wherein the arranging of the section of the conductive wire comprises using an automated wire mounting system.Clause 32. The method of clause 31 , wherein the automated wire mounting system comprises a movable guide comprising a through hole for guiding the conductive wire around the radio module.Clause 33. The method of clause 31 , wherein the automated wire mounting system comprises one or more articulated robotic members, the articulated robotic members comprising a gripping mechanism for gripping the conductive wire and for moving the gripped conductive wire around the package of the radio module.Clause 34. The method of clause 33, wherein moving the gripped conductive wire around the package of the radio module comprises forming a knot on a surface of the package.Clause 35. The method according to any of clauses 33 or 34, wherein the articulated robotic members comprise one or more programmable robotic arms.Clause 36. The method according to any of clauses 30 to 35, wherein the automated wire arranging system further comprises: one or more supports and / or rollers for contacting the conductive wire so as to maintain a pre-defined level of tension at least at the section of the conductive wire to be arranged around the package of the radio module.Clause 37. The method according to any of clauses 20 to 36, further comprising: after the arranging of the section of the conductive wire, cutting a section out of the conductive wire, wherein the cut section comprises at least the section supported by the package of the radio module and two end sections at two ends of the cut section not supported by the package of the radio module.Clause 38. The method according to any of clauses 20 to 37, wherein the radio module comprises a magnetically permeable material.Clause 39. The method according to clause 38, wherein the magnetically permeable material comprises a ferrite material selected from the following: ferrite Fe, manganese-zinc ferrite Mn3Zn(i-s) Fe2O4, nickel-zinc ferrite NisZn(i-6) Fe2O4, cobalt ferrite, strontium ferrite, barium ferrite, or combinations thereof.Clause 40. The method according to clause 38 or clause 39, wherein the package of the radio module comprises the magnetically permeable material.Clause 41 . The method according to clause 40, wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprising the magnetically permeable material.Clause 42. The method according to any of clauses 40 or 41 , wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprising the magnetically permeable material; and wherein the first region extends beyond the section of the conductive wire supported by the package.Clause 43. A system for manufacturing a radio frequency identification, RFID, tag, the system comprising: an automated picking and placing system for picking up a radio module and placing the radio module at a pre-defined location, wherein the radio module comprises an integrated circuit comprising RFID circuitry, an inductive element configured to enable inductive coupling of the RFID circuitry, and a package at least partially encapsulating the integrated circuit and the inducive element; and an automated wire mounting system for arranging a section of a conductive wire on the package of the radio module placed at the pre-defined location such that the section of the conductive wire is supported by the package.Clause 44. The system of clause 43, wherein the automated wire mounting system comprises one or more articulated robotic members and / or a rotating member, for mounting the conductive wire on the package of the radio module placed at the pre-defined location.Clause 45. The system of clause 43, wherein the automated wire mounting system comprises an automated knotting system, comprising one or more articulated robotic members, for knotting the conductive wire around a surface of the package of the radio module placed at the pre-defined location.Clause 46. The system of clause 43, wherein the automated wire mounting system comprises a stitching system, comprising one or more articulated robotic members, for stitching the conductive wire on the package of the radio module placed at the pre-defined location.Clause 47. The system of any of clauses 43 to 46, further comprising: a central control computing device comprising at least one processor; and at least one memory device storinginstructions that, when executed by the at least one processor, cause the central computing device at least to control at least the automated picking and placing system and the automated wire mounting system.Clause 48. The system of any of clauses 43 or 47, wherein the automated wire mounting system comprises: a movable guide comprising a through hole for guiding the conductive wire around the radio module, or one or more articulated robotic members, the articulated robotic members comprising a gripping mechanism for gripping the conductive wire and for moving the gripped conductive wire around the package of the radio module.Clause 49. A wire reel having conductive wire wound thereon, said wound conductive wire holding a plurality of radio modules so as to form a plurality of RFID tags according to any of clauses 1 to 19Clause 50. A radio frequency identification, RFID, tag comprising: a radio module comprising an integrated circuit comprising RFID circuitry, an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element, a conductive wire, configured to act as the antenna of the RFID tag, comprising a section arranged substantially around the radio module, wherein the antenna exhibits a longitudinal direction, and the conductive wire is arranged in an asymmetrical manner to the radio module with respect to a plane, the plane being perpendicular to the longitudinal direction of the antenna and substantially aligned with the radio module.Clause 51. The RFID tag of clause 50, wherein the section of the conductive wire arranged substantially around the radio module is supported by the package of the radio module.Clause 52. The RFID tag of clause 51 , wherein the section of the conductive wire supported by the package of the radio module comprises one or more turns around the package.Clause 53. The RFID tag of any of clauses 51 or 52, wherein the conductive wire is wound on a surface of the package of the radio module and it comprises two non-wound end sections,the two non-wound end sections extending from the radio module in a substantially straight manner and the two non-wound end sections being of different length.Clause 54. The RFID tag of any of clause 51 or 52, wherein the conductive wire is knotted on a surface of the package of the radio module and it comprises two non-knotted end sections, the two non-knotted end sections extending from the radio module in a substantially straight manner and the two non-knotted end sections being of different length.Clause 55. The RFID tag of any of clauses 51 or 52, wherein the conductive wire is stitched on a surface of the radio module and it comprises two non-stitched end sections, the two nonstitched end sections extending from the radio module in a substantially straight manner and the two non-stitched end sections being of different length.Clause 56. The RFID tag of clause 50, wherein the conductive wire and the radio module are individually fixed onto a substrate.Clause 57. The RFID tag of clause 56, wherein the conductive wire is fixed to the substrate by a retention element, particularly by a thread sewing the conductive wire to the substrate, and the radio module is fixed to the substrate by gluing, sewing or inserting in a pouch type enclosure built in the substrate.Clause 58. The RFID tag according to any of clauses 50 to 57, wherein the radio module comprises a magnetically permeable material.Clause 59. The RFID tag according to clause 58, wherein the magnetically permeable material comprises a ferrite material selected from the following: ferrite Fe, manganese-zinc ferrite Mn3Zn(i-s) Fe2O4, nickel-zinc ferrite NisZn(i-6) Fe2O4, cobalt ferrite, strontium ferrite, barium ferrite, or combinations thereof.Clause 60. The RFI D tag according to clause 58 or clause 59, wherein the package of the radio module comprises the magnetically permeable material.Clause 61 . The RFID tag according to clause 60, wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprising the magnetically permeable material.Clause 62. The RFID tag according to any of clause 60 or 61 , wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprising the magnetically permeable material; and wherein the first region extends beyond the section of the conductive wire supported by the package.Clause 63. A radio frequency identification, RFID, tag comprising: a radio module comprising an integrated circuit comprising RFID circuitry, an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element, a conductive wire, configured to act as the antenna of the RFID tag, comprising a section arranged substantially around the radio module, wherein the antenna exhibits a longitudinal direction, and the conductive wire is arranged in an asymmetrical manner to the inductive element with respect to a plane, the plane being perpendicular to the longitudinal direction of the antenna and substantially aligned with the inductive element.Clause 64. The RFID tag of clause 63, wherein the section of the conductive wire arranged substantially around the radio module is supported by the package of the radio module.Clause 65. The RFID tag of clause 63, wherein the conductive wire and the radio module are individually fixed onto a substrate.Clause 66. A method of manufacturing a radio frequency identification, RFID, tag, the method comprising: providing a radio module for the RFID tag, wherein the radio module comprises an integrated circuit, comprising RFID circuitry, an inductive element configured to enable inductive coupling of the RFID circuitry, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element; arranging a section of a conductive wire substantially around the radio module, the conductive wire being configured to act as the antenna of the RFID tag, and arranging the conductive wire in an asymmetric manner to the radio module in respect to a plane perpendicular to a longitudinal direction of the antenna of the RFID tag and substantially aligned with the radio module.Clause 67. The method of claim 66, wherein arranging the section of a conductive wire around the radio module comprises arranging the section of conductive wire such that the section supported by the package of the radio module.Clause 68. The method of clause 66, comprising providing a substrate, the method further comprising: fixing the radio module to the substrate, and fixing the conductive wire to the substrate.Clause 69. The method of clause 68, wherein fixing the conductive wire to the substrate comprises sewing the conductive wire to the substrate.Clause 70. The method of any of clauses 68 or 69, wherein fixing the radio module to the substrate comprises gluing the package of the radio module on the substrate, sewing package of the radio module to the substrate, or arranging the package of the radio module in a pouch type enclosure built in the substrate.Clause 71. The method according to any of clauses 63 to 70, wherein the radio module comprises a magnetically permeable material.Clause 72. The method according to clause 71 , wherein the magnetically permeable material comprises a ferrite material selected from the following: ferrite Fe, manganese-zinc ferrite Mn3Zn(i-s) Fe2O4, nickel-zinc ferrite NisZn(i-6) Fe2O4, cobalt ferrite, strontium ferrite, barium ferrite, or combinations thereof.Clause 73. The method according to clause 71 or clause 72, wherein the package of the radio module comprises the magnetically permeable material.Clause 74. The method according to clause 73, wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprising the magnetically permeable material.Clause 75. The method according to any of clauses 73 or 74, wherein the package comprises a first region and a second region, the first region comprising the magnetically permeable material and the second region not comprisign the magnetically permeable material; andwherein the first region extends beyond the section of the conductive wire supported by the package.

[0204] This written description uses examples to disclose the teaching, including the preferred embodiments, and also to enable any person skilled in the art to practice the teaching, including making and using any devices or systems and performing any incorporated methods. The patentable scope is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspects, can be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application. If reference signs related to drawings are placed in parentheses in a claim, they are solely for attempting to increase the intelligibility of the claim, and shall not be construed as limiting the scope of the claim.

Claims

CLAIMS1. A radio frequency identification, RFID, tag comprising: a radio module comprising an integrated circuit comprising RFID circuitry, an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element, a conductive wire, configured to act as the antenna of the RFID tag, comprising a section supported by the package of the radio module, wherein the section of the conductive wire supported by the package of the radio module comprises exactly two turns around the package.

2. The RFI D tag of claim 1 , wherein the section of the conductive wire is wound on a surface of the package of the radio module and the surface of the package comprises one or more grooves for positioning the conductive wire.

3. The RFID tag of any previous claim, wherein the package comprises a first flange, a second flange, and a center portion arranged between the first flange and the second flange, the first flange and the second flange extending outwards from the center portion, and the section of conductive wire being supported by the center portion.

4. A radio frequency identification, RFID, tag comprising: a radio module comprising an integrated circuit comprising RFID circuitry, an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element, a conductive wire, configured to act as the antenna of the RFID tag, comprising a section supported by the package of the radio module , wherein the package comprises a plurality of holes and the section of conductive wire is stitched on the package via the holes.

5. The RFID tag of claim 4, wherein the package comprises a center portion and a flange extending outwards from the center portion, the flange comprising the plurality of holes.

6. The RFID tag of any previous claim, wherein the conductive wire comprises an insulating outer layer.

7. The RFID tag of any previous claim, wherein the inductive element is an integrated inductive element incorporated in the integrated circuit.

8. A wire reel having a conductive wire wound thereon, said wound conductive wire holding a plurality of radio modules so as to form a plurality of RFID tags according to any of claims 1 to 7, and wherein the wound conductive wire is the conductive wire of the RFID tags.

9. A method of manufacturing a radio frequency identification, RFID, tag, the method comprising: providing a radio module for the RFID tag, wherein the radio module comprises an integrated circuit, comprising RFID circuitry, an inductive element configured to enable inductive coupling of the RFID circuitry, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element; and arranging a section of a conductive wire such that the section of the conductive wire is supported by the package, wherein a first end of the conductive wire is wound around a supply reel of a wire reeling system and a second end of the conductive wire is wound around a take-up reel of the wire reeling system, the method further comprising: following the arranging of the section of the conductive wire, reeling, using the wire reeling system, the conductive wire from the supply reel to the take-up reel so as to move the radio module towards the take-up reel.

10. The method of claim 9, wherein arranging the section of the conductive wire comprises winding the conductive wire for exactly two turns on the surface of the package.

11. The method of claim 9, wherein arranging the section of the conductive wire comprises stitching the section of conductive wire through a plurality of holes.

12. The method of claim 11 , wherein the method comprises:- stitching by puncturing the package during the stitching for creating the plurality of holes, or- providing a plurality of pre-prepared holes on the package before the stitching.

13. The method according to any of claims 9 to 12, wherein the arranging of the section of the conductive wire comprises using an automated wire mounting system, and wherein the automated wire mounting system comprises: a movable guide comprising a through hole for guiding the conductive wire around the radio module, or one or more articulated robotic members, the articulated robotic members comprising a gripping mechanism for gripping the conductive wire and for moving the gripped conductive wire around the package of the radio module.

14. A radio frequency identification, RFID, tag comprising: a radio module comprising an integrated circuit comprising RFID circuitry, an inductive element configured to inductively couple the RFID circuitry to an antenna of the RFID tag, and a package configured to encapsulate, at least in part, the integrated circuit and the inductive element, a conductive wire, configured to act as the antenna of the RFID tag, comprising a section arranged substantially around the radio module, wherein the antenna exhibits a longitudinal direction, and the conductive wire is arranged in an asymmetrical manner to the radio module with respect to a plane that is perpendicular to the longitudinal direction of the antenna and is substantially aligned with the radio module.

15. The RFID tag of claim 14, wherein the section of the conductive wire arranged substantially around the radio module is supported by the package of the radio module.

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