SE544137C2

SE544137C2 - Package system with self-grounded rfid tag arrangement

Info

Publication number: SE544137C2
Application number: SE2050512A
Authority: SE
Inventors: Ilkka Yli-Peltola; Lauri Huhtasalo
Original assignee: Digital Tags Finland Oy
Priority date: 2020-05-04
Filing date: 2020-05-04
Publication date: 2022-01-11
Also published as: FI130849B1; FI20226065A1; WO2021224769A1; SE2050512A1

Abstract

A package system (1) and a method for producing such as system are disclosed. The package system comprises a container (2) for storing goods and made of a non-conductive material, and an RFID tag arrangement (3) integrated with the container. The RFID tag arrangement comprises a radiating layer (31) attached to an exterior side of the container and a ground layer (32) attached to an interior side of the container, the ground layer and the radiating layer being parallel to each other and at least partly overlapping when seen from a direction perpendicular to said layers. The ground layer (32) and the radiating layer (31) are thereby separated by the non-conductive material of the container. An RFID chip (34) is connected to the radiating layer (31). The antenna may function as a patch antenna or a PIFA antenna and provides excellent radiation properties even for containers containing metal covered goods, liquids, and the like.

Description

PACKAGE SYSTEM WITH SELF-GROUNDED RFID TAG ARRANGEMENF F°rmatted Technical field of the invention The present invention is related to a package system with a self-grounded radio frequency identification (RFID) tag arrangement. Theinvention further relates to a manufacturing method for producing such a package system.

BackgroundRFID tags are nowadays used more and more frequently, and for a wide variety of applications, such as in smart labels/tags. The RFID tag isconventionally arranged as a flat configured transponder, e.g. arranged undera conventional print-coded label, and includes a chip and an antenna. Thelabels/tags are often made of paper, fabric or plastics, and are normallyprepared with the RFID inlays laminated between a carrier and a label media,e.g. for use in specially designed printer units. Smart labels offer advantagesover conventional barcode labels, such as higher data capacity, possibility toread and/or write outside a direct line of sight, and the ability to read multiplelabels or tags at one time. lt is also known to incorporate RFID labels directly in a packagingmaterial, to form so-called intelligent packaging products.

Most commercially available RFID tags uses dipole, loop or slot typesantennas. Such antennas are advantageous, due to their small size, simplestructure and relatively low production costs.

However, a problem with most commercially available RFID tagantennas when arranged on a package is that the radiation properties may beseverely distorted by the content of the package. Packaging like corrugatedboard shipment boxes are often used to transport items which are notcompatible with conventional RFID tags. Such items may be metallic orpacked in metallic primary packaging, or may contain liquid. For example, thisrelates to cigarette packs with aluminum wrapper inside, various snacks packed into metallized film bags, metallized packages containing juice, and other beverages and foodstuff, and the like. However, there is still a need toidentify also such packages with RFID systems.

Typical low-cost RFID labels are not able to be interrogated well whenapplied directly or very close to metallic or liquid objects. Sometimes in theshipment box, there is a space of free air__at the top. Then a standard UHFRFID tag can be applied to such position in the package, where there is airbehind the corrugated board material. But very often, to save transport costs,the package is completely full with the items. ln this case, standard UHF RFIDtags will not work properly to identify the packages. Further, the placement ofthe RFID tag in relation to the goods in the packages are often difficult tocontrol properly, making it difficult to use standard RFID tags even when thereare empty spaces in the packages.

To this end, it has been known to use foam tags with PIFA antennas.The PIFA antennas are formed into a folded structure, and insulative materialsuch as plastic foam is inserted between the folded parts. The PIFA tags aretypically injection molded into a protective molded envelope. However, adrawback with such RFID tags is that they are very costly to produce. lnaddition, these RFID tags are relatively thick, typically with a thickness of 6-12mm, making them unsuitable for use for many packages, and also increasesthe risk that the tags fall of or become damaged during handling of thepackage. lt is also difficult to make such RFID tags recyclable, thereby addingto the overall handling costs. lt has also been known to use RFID tags which are arranged toprotrude out from the packages, so called flag tags. However, when shipmentboxes are palletized, there is normally no space for such protruding tags.Further, there is here an even greater risk that the tags become damagedduring handling, both during palletizing, and handling before and after that.

There is therefore still a need for an improved package system with anRFID tag arrangement which can be made more versatile, and which isinsensitive to the content of the package, which has good and improved RF performance, and/or which can be produced cost-effectively.

Summarylt is therefore an object of the present invention to provide a package system including an RFID tag arrangement and a manufacturing method forsuch a package, which a||eviates at least part of the above-discussedproblems, and at least partially address one or more of the above-mentionedneeds.

This object is obtained by means of a package system and amanufacturing method in accordance with the appended claims.

According to a first aspect of the invention there is provided a packagesystem oomprising: a container for storing goods and made of a non-conductive material; an RFID tag arrangement integrated with the container, wherein theRFID tag arrangement com prises a radiating layer attached to an exteriorside of the container, a ground layer attached to an interior side of thecontainer, the ground layer and the radiating layer being parallel to each otherand at least partly overlapping when seen from a direction perpendicular tosaid Iayers, the ground layer and the radiating layer thereby being separatedby the non-conductive material of the container, and an RFID chip connectedto the radiating layer.

The container may e.g. be arranged to contain goods which attenuatesor distorts electromagnetic wave signals at frequencies where the RFID tag isarranged to operate. The RFID tag may e.g. be configured for operation at afrequency within the range of 860-960 MHz. Such goods may e.g. be metallicobjects, or objects enclosed in metallic or partly metallic packages, such ascigarette packages, comprising aluminum wrappings. The goods may alsocontain liquid.

The RFID tag arrangement is preferably configured for operation at theUHF frequency band, and in particular at a frequency within the range of 860-960 MHz.

Since the RFID tag arrangement here comprises its own ground plane,which is arranged between the RFID antenna and the goods in the container,the properties of the RFID tag are essentially not affected by any attenuation or distortion from the goods, regardless of the content or packaging of the goods. The RFID tag is here totally insensitive to the contents ofthecontainer.

The RFID tag also has very good performance, and e.g. provide asgood reading performance as conventionally used RFID tags.

Further, since the antenna uses a part of the container as separationlayer between the radiation layer and the ground layer, the RFID tagarrangement is very thin, and also very cost-efficient to produce. The lowcosts are associated with the few parts needed to form the antenna, and thatalready existing material, i.e. the material of the container, is used also as apart of the antenna. ln addition, the antenna is easy to manufacture and tomount on the container. Compared to presently used PIFA RFID tags, the RFID tag of the present invention can be produced to a cost which is at least .\.\ t times lower, and possibly up to about æs--kïišvšè-t: .=_ lower.

Since the RFID tag of the present invention can be made very thin, andvery well integrated in the package, the risk of damages and the like to theRFID tag becomes very low. Hence, the package system becomes veryrobust, with very low risk of the RFID tag becoming inoperative duringhandling and use of the package. Thus, adequate RFID communication canbe ensured during the entire longevity of the container.

Since a very limited amount of material is used to form the RFID tag,and since environmentally friendly material may be used, the entire packagesystem can easily be made recyclable, without the need to detach the RFIDtag arrangement. ln one embodiment, the container comprises an opening, wherein theground layer and the radiating layer are arranged to abut the opening, andwherein the RFID tag arrangement further comprises a bridge connecting theground layer and the radiating layer over the opening. Thus, the radiatinglayer here continues into the ground layer, via the bridge, and when arranged on the container, the bridge extends over the length of the opening, with ii? i; plane generally perpendicular to the planes of the ground layer and theradiating layer. Hereby, the radiating layer and the ground layer of the RFIDtag arrangement preferably form a planar inverted-F antenna (PIFA). The radiating layer may have a resonant length of essentially a quarter of a wavelength at an operating frequency of the RFID tag arrangement. At e.g.900 MHz, the wavelength would be about 33 cm, and a quarter of thewavelength would be about 8 cm. Thus, the RFID tag with this antenna canbe made relatively compact also in the width and length direction.

With the PIFA structure, electromagnetic fields concentrate betweenthe radiator, i.e. the radiating layer, and antenna ground plane, i.e. the groundlayer, in a controlled manner. The antenna is tolerant and insensitive tomaterials behind the antenna ground plane. Also, metal contentwithin thecontainer would even be an advantage, since it may form part of, and extend,the antenna ground.

The antenna may be inserted into an opening of the container-,- andfolded over the wall at the sides of the opening. The opening may e.g. be aseparately made opening, made specifically for this purpose. However, it isalso feasible to use already existing opening, i.e. openings provided for otherreasons, such as opening provided at the top of the container, or handleopenings arranged at the sides of the container. ln an alternative embodiment, the RFID tag arrangement is free fromany galvanic connection between the radiating layer and the ground layer.Hereby, the radiating layer and the ground layer of the RFID tag arrangementpreferably form a patch antenna. Here, the radiating layer preferably has aresonant length of essentially half a wavelength at an operating frequency ofthe RFID tag arrangement. At e.g. 900 MHz, the wavelength would be about33 cm, and a half wavelength would be about 16 cm. Thus, the RFID tag withthis antenna is less compact than the first discussed embodiment, but is stillsufficiently oompact in the width and length direction to fit most types ofcontainers. ln this embodiment, the ground layer and the radiating layer may stillbe arranged adjacent to an opening of the package. The ground layer and theradiating layer may e.g. be provided on a substrate, which is adhered to thecontainer by folding it over the opening, in same way as for the antenna of thefirst embodiment. However, since there is no galvanic connection betweenthe ground layer and the radiating layer in this second embodiment, the layers may also be arranged at any place of the container, without the need for any openings or the like, as long as the relative positioning of the ground layerand radiation layer is maintained. ln both embodiments of the antenna, the antenna can be made verythin, thus hardly adding any noticeable thickness or weight to the container.

Preferably, the RFID tag arrangement are arranged at a side of thecontainer, but for certain applications it is also feasible to arrange the RFIDtags on the top or bottom of the container.

The radiating layer may have width and length dimensions which arethe same as, or smaller than, the width and length dimensions of the groundlayer. Thus, the dimensions of the radiating layer may be essentially the sameas the dimensions of the ground layer. Alternatively, the dimensions of theground layer may be somewhat greater than the dimensions of the radiatinglayer, or even significantly greater. Put differently, the radiating layer may bearranged totally within the bounds of the ground layer, when seen from adirection perpendicular to said layers.

The RFID tag arrangement may further comprise at least one feedingline, connecting a terminal of the RFID chip to a determined position of theradiating layer. The feeding line may e.g. connect the RFID chip terminal to aposition relatively centrally in the radiating layer, in the vicinity of one of theends of the radiating layer, or the like. ln an embodiment where the radiationlayer is galvanically connected to the ground layer, such as in the PIFAembodiment, the feeding line may connect the terminal of the chip to aposition of the radiation layer being distant from and essentially opposite tothe connection to the ground layer, and the other terminal of the chip may beconnected to the ground layer. ln an embodiment where the radiation layer isgalvanically separated from the ground layer, such as in the patch antennaembodiment, two feeding lines may be provided, connecting the terminals ofthe chip to two opposite sides of the radiation layer.

The RFID chip may e.g. be a high performance and low-cost IC chip,such as the commercially available NXP UCode 8.

The non-conductive material may be any dielectric material which isalso suitable for forming a container. ln an embodiment, the non-conductive material is at least one of cardboard, plastic and wood. Preferably, the non- conductive material is cardboard, and preferably at least one of paperboardand corrugated fiberboard. Cardboard here generally indicates a heavy- duty paper-based products having greater thickness and superior durability orother specific mechanical attributes to paper; such as foldability, rigidity andimpact resistance. Cardboard includes paperboard, which is thick sheets »ofpaper¿_»~based material, typically of a thickness exceeding 0.25 mm, andcorrugated fiberboard, which is a oombination of paperboards, such as acombination of two flat liners and one inner corrugated medium.

The container may have any shape and dimensions. However,preferably, the container is a packaging box, and preferably with a generallyrectangular cross-section and all sides flat, such as a folding carton, a bulkbox or a corrugated box. However, the cross-section need not be rectangular,but rounded or beveled edges may be provided, and also elongated, round oroval shapes are feasible. Polygonal shapes, such as hexagons and octagons,are also feasible. Further, at least some of the sides may be non-flat, such asbeing domed.

The non-conductive material of the container separating the radiatinglayer and the ground layer may have a thickness in the range of 1-10 mm,and preferably in the range of 2-7 mm, and most preferably in the range of 2-5 mm, such as about 3 mm. The thickness influences the amount ofelectromagnetic coupling between the radiating part and the ground layer,and consequently also the performance of the antenna.

The antenna formed by the radiation layer may have various shapesand dimensions, as is per se known in the art. For example, the radiationlayer may extend in a generally linear direction, or may extend in a non-linearway, and may have a uniform width, or a width varying over the length. Partsof the antenna may also be folded or curved, thereby extending in two ormore directions. ln one embodiment, the RFID tag arrangement comprises a dielectricsubstrate on which at least one of said radiating layer and said ground layerare provided, said substrate being connected to the interior and/or exterior side of the container by an adhesive. The dielectric substrate may be realized in various ways. ln one embodiment, the dielectric separation layer is made ofat least one of: paper, board, polymer film, textile and non-woven material.

The dielectric substrate may have a thickness in the range of 20-300pm, and preferably in the range 50-200 pm, and more preferably in the range50-150 pm, and most preferably in the range 70-130 pm, such as 100 pm.

Additionally, or alternatively, at least one of the radiating layer and theground layer may be printed directly on the interior and/or exterior surface ofthe container. ln such an embodiment, the printing can be made on differentsides of a substrate forming the container. Alternatively, the printing can bemade on a single side, and extending over a folding line into a flap, arrangedto be downfolded when the container is mounted.

At least one of the radiating layer and the ground layer may be formedwith an essentially solid conductive material extending over the outer boundsof the layer. ln such an embodiment, the radiating layer forms an outerperimeter, and is filled, or essentially, filled with conductive material inside thisperimeter. ln one embodiment, the radiating layer is formed by such a solidshape. ln one embodiment, the ground layer is formed by such a solid shape.ln one embodiment, both the radiating layer and the ground layer are formedby such a solid shape.

Additionally, or alternatively, at least one of the radiating layer and theground layer are formed with an solid conductive material extending along theperimeter of the outer bounds of the layer, but with a plurality of non-conductive areas in the interior of the layer. ln such embodiments, at leastone of the radiating layer and the ground layer may comprise a mesh formedby conductive strips, and with non-conductive areas between said strips.

The RFID tag arrangement may be either passive, i.e. powered by areader's electromagnetic field, or active, i.e. powered by an onboard battery.

The radiating layer and the ground layer may be made of any material,as long as the material is conductive. The radiating layer and the ground layermay be made by the same material, but may alternatively be made ofdifferent materials. For example, the layers may be formed by aluminum, butother metals, such as silver, and alloys may also be used. Forming of the layers on the substrate, be it directly on the container or on a separate substrate, can be made in various ways, as is per se known in the art, suchas by printing with conductive ink, such as silver ink, by first providing aconductive layer on the substrate and subsequently removing or forming thisconductive layer into the desired shape, e.g. by means of grinding, cutting,etching or the like.

According to another aspect of the invention, there is provided amethod for manufacturing a package, comprising: providing a container for storing goods and made of a non-conductivematerial; integrating an RFID tag arrangement with the container, by attaching aradiating layer of the RFID tag arrangement to an exterior side of thecontainer, and attaching a ground layer to an interior side of the container, theground layer and the radiating layer being parallel to each other and at leastpartly overlapping when seen from a direction perpendicular to said layers,the ground layer and the radiating layer thereby being separated by the non-conductive material of the container, and by connecting an RFID chip to theradiating layer. ln accordance with this aspect, similar features and advantages asdiscussed in the foregoing, in relation to the first aspect, may be obtained. lt will be appreciated that the above-mentioned detailed structures andadvantages of the first aspect of the present invention also apply to the furtheraspects of the present invention.

These and other aspects of the invention will be apparentfrom and elucidated with reference to the embodiments described hereinafter.

Brief description of the drawinas For exemplifying purposes, the invention will be described in closerdetail in the following with reference to embodiments thereof illustrated in theattached drawings, wherein: Fig. 1a and 1b are illustrations of a package system in acoordance withan embodiment of the invention, where Fig. 1 is a perspective side view of thepackage system, and Fig. 1b is a cross-sectional view of the package system of Fig. 1a; Fig. 2a-c are illustrations of an RFID tag arrangement for use in apackage system in accordance with an embodiment of the invention, whereinFig. 2a is a perspective view of the RFID tag arrangement, Fig. 2b is aperspective view illustrating the RFID tag arrangement when attached to acontainer, and Fig. 2c is a cross-sectional view of the RFID tag arrangementwhen attached to a container; Figs. 3a-b illustrate an RFID tag arrangement for use in a packagesystem in accordance with another embodiment of the present invention,wherein Fig. 3a is a top view of the RFID tag arrangement in a flat state, priorto folding, and Fig. 3b is perspective view of the RFID tag arrangement in afolded state; Fig. 4a-b illustrate an RFID tag arrangement for use in a packagesystem in accordance with yet another embodiment of the present invention,wherein Fig. 4a is a top view of the RFID tag arrangement in a flat state, priorto folding, and Fig. 4b is perspective view of the RFID tag arrangement in anattached, folded state; Figs. 5a-b illustrate an RFID tag arrangement for use in a packagesystem in accordance with yet another embodiment of the present invention,wherein Fig. 5a shows a perspective view of the RFID tag arrangement in anattached, folded state, without any container, and Fig. 5b shows the sameRFID tag arrangement as in Fig. 5a, attached to a oontainer wall; Fig. 6 is a cross-sectional illustration of a Iayered RFID tagarrangement structure, in accordance with an embodiment of the presentinvention; Figs. 7 and 8 are perspective views of alternative package systems, inaccordance with embodiments of the present invention; Fig. 9 is a diagram illustrating the reading range for a conventional RFID tag arrangement in a packaging system; Detailed description of preferred embodimentsln the following detailed description preferred embodiments of the invention will be described. However, it is to be understood that features of 11 the different embodiments are exchangeable between the embodiments andmay be combined in different ways, unless anything else is specificallyindicated. lt may also be noted that, for the sake of clarity, the dimensions ofcertain components, parts and elements illustrated in the drawings may differfrom the corresponding dimensions in real-life implementations of theinvention, such as the thickness of various layers, the relative dimensions ofthe different antenna parts, etc.

With reference to figs. 1a and 1b, an embodiment of a package system1 comprises a container 2 for storing goods and made of a non-conductivematerial. The container can oontain any types of goods and items, but isparticularly suited to contain goods which attenuates or distortselectromagnetic wave signals at frequencies where an RFID tag is arrangedto operate. The RFID tag may e.g. be configured for operation at a frequencywithin the range of 860-960 MHz. Such goods may e.g. be metallic objects, orobjects enclosed in metallic or partly metallic packages, such as cigarettepackages, comprising aluminum wrappings. The goods may also containliquid or foodstuff.

The non-conductive material may be any dielectric material which isalso suitable for forming a container, such as cardboard, plastic and/or wood.Preferably, the non-conductive material is cardboard, and preferably at leastone of paperboard and corrugated fiberboard.

The container may have any shape and dimensions. However,preferably, the container is a packaging box, and preferably with a generallyrectangular cross-section and all sides flat, as in the illustrative example ofFig. 1a and 1b, such as a folding carton, a bulk box or a corrugated box.However, the cross-section need not be rectangular, but rounded or bevelededges may be provided, and also elongated, round or oval shapes arefeasible. Polygonal shapes, such as hexagons and octagons, are alsofeasible. Further, at least some of the sides may be non-flat, such as beingdomed.

The container may have an opening 21 in a sidewall, e.g. for use as ahandle. The container is also preferably provided with an access opening 22 at the top, or on one side, for accessing the container during packing and 12 unpacking. The access opening 22 may be closed with a lid, or by one or twoflaps 23, 24, which may be foldable to close the access opening.

As best seen in Fig. 1b, the container, when packed, may be filled withgoods 4, such that hardly any free space remains in the container. The goodsmay be of a type that distorts radio frequency communication, such as beingof metal or metallized, containing liquid, and the like.

The container is also provided with an RFID tag arrangement 3,integrated with the package. Various embodiments of the RFID tagarrangement will be discussed in more detail in the following. ln a first embodiment of the RFID tag arrangement, as illustrated inFigs. 2a-c, the RFID tag comprises a radiating layer 31, attached to anexternal side of the container, and a ground layer 32 attached to an internalside of the container. A bridge 33 galvanically connects the radiating layerand the ground layer.

When arranged on the container, the radiating layer 31 and the groundlayer 32 are arranged so that the sides being connected to the bridge 32abuts an opening of the container, such as the handle opening 21, so that thebridge 33 extends through the length of the opening.

Thus, the radiating layer 31 and the ground layer are generally parallelto each other, and extend in a first direction, which is also parallel to the sideof the container containing the opening. The bridge forms a plane extendingin a direction which is generally perpendicular to the first direction. However,depending on the shape of the opening, the bridge may also be slightlyrounded, or beveled. The bridge is preferably arranged in contact with the' attached to this.

The radiating layer 31 and the ground layer 32 are further preferably sidewall of the arranged to at least partly overlap each other when seen from a directionperpendicular to these layers, i.e. when seen from the second direction. ln theillustrative example, there is essentially a oomplete overlap.The ground layer 31 and the radiating layer 32 are hereby separated by the non-conductive material of the container 2. Thus, no additionalinsulation between the two layers are needed, and the non-conductive material of the container serves the dual purposes of both forming the 13 container and providing insulation between the radiation layer and the groundlayer. ln the illustrative example, the radiating layer 31 generally has theshape of an elongate rectangle, having one of its short sides abutting theopening and being connected to the bridge 33. However, many other shapesare also feasible. The ground layer 32 here has shapes and dimensionsgenerally corresponding to those of the radiating layer 31. However, theground layer may also have different shapes and/or dimensions. Forexample, the ground layer can be at least slightly larger than the radiatinglayer, such as being longer and/or wider.

The bridge may generally have the same width as the radiating layerand/or the ground layer, thereby providing a continuation of the radiating layerinto the ground layer. However, the bridge may also have other shapes ordimensions, such as forming a narrow bridge between the radiating layer andthe ground layer.

An RFID chip 34 is further provided. One terminal of the RFID chip isconnected to the radiating layer 31, preferably through a feeding line 35, sothat the connection is made to a part at some distance from the bridge 33.The connection can e.g. be made at a position closer to the short sideopposite to the bridge than to the short side connected to the bridge. ln someembodiments, the connection can be made to a position in the vicinity of theend opposite to the bridge.

Another terminal of the RFID chip 34 may be connected to the groundlayer, preferably through a feeding line 36, so that the connection is made toa part at some distance from the bridge 33. The connection can e.g. be madeat a position closer to the short side opposite to the bridge than to the shortside connected to the bridge. ln some embodiments, the connection can bemade to a position in the vicinity of the end opposite to the bridge. ln this embodiment, the RFID chip is arranged between the radiatinglayer 31 and the ground layer 32, but may also be placed in other positions.

The anten na of this RFID tag arrangement generally functions as aPIFA antenna. 14 Another embodiment of an RFID tag arrangement is shown in Figs. 3a-b. This RFID tag arrangement is similar to the one discussed in relation toFigs. 2a-c, and is attached to the container in the same way. Thus, apart fromthe details specified in the following, the RFID tag arrangement of thisembodiment is constituted in the same way as the one previously discussed. ln this embodiment, the RFID chip 34 is arranged on the radiating layer31, and e.g. relatively centrally on this layer. However, it may also bearranged more or less displaced towards one or two of the sides.

Suitable dimensions of the radiation layer and the ground layer aredependent on various factors, such as the operating frequency, the dielectricconstant and thickness of the container material separating the radiating layerfrom the ground layer, etc. ln some embodiments, the overall length of theradiation layer and the ground layer may be in the range of 20-200 mm, suchas 50-150 mm, such as 80-120 mm, and preferably in the range of 90-110mm, and more preferably in the range of 95-105 mm, such as 98 mm. Thewidth of the radiation layer and the ground layer may be in the range of 10-100 mm, such as 15-75 mm, such as 20-60 mm, and preferably in the rangeof 30-50 mm, and more preferably in the range of 35-45 mm, such as 40 mm.Such dimensions make the RFID tag arrangement suitable for use at UHFfrequencies.

The RFID chip is arranged in a cut-out portion, which forms a non-conductive area 37 within the radiating layer. Two feeding lines 35', 36'extend through the non-conductive area 37, to the terminals of the chip 34. lnthis embodiment, a first of the feeding lines 35' extends away from the bridge33, and a second of the feeding lines 36' extends towards the bridge 33. Thefirst feeding line 35' connects to a part of the radiating layer being at adistance from the bridge, and at, or in the vicinity of, the end opposite to thebridge. The second feeding line 36' oonnects to a part of the radiating layercloser to the bridge, and at, or in the vicinity of the end connecting to thebridge.

The anten na of this RFID tag arrangement also generally functions as a PIFA antenna. ln yet another embodiment of the RFID tag arrangement, as illustratedin Figs. 4a-b, the RFID tag also comprises a radiating layer 31, attached to anexternal side of the container, and a ground layer 32 attached to an internalside of the container. However, in this embodiment there is no bridgeconnecting the radiating layer and the ground layer, and the layers aregalvanically separated.

When arranged on the container, the radiating layer 31 and the groundlayer 32 may even in this embodiment be arranged so that one side of eachlayer buts an opening of the container, such as the handle opening 21.However, since there is no bridge formed between the layers, the layers mayhere also be arranged at some distance from the opening, or even at places of the container not having any opening. g, in this embodiment, the radiating layer 31 and the groundlayer are generally parallel to each other, and extend in a first direction, whichis also parallel to the side of the container containing the opening. Theradiating layer 31 and the ground layer 32 are further preferably arranged toat least partly overlap each other when seen from a direction perpendicular tothese layers, i.e. when seen from a direction perpendicular to the firstdirection. ln the illustrative example, there is essentially a complete overlap.

Similar to the first discussed embodiment, the ground layer 31 and theradiating layer 32 are here separated by the non-conductive material of thecontainer 2. ln the illustrative example, the radiating layer 31 generally has theshape of an elongate rectangle, having one of its short sides abutting theopening and being connected to the bridge 33. However, many other shapesare also feasible. The ground layer 32 here has shapes and dimensionsgenerally corresponding to those of the radiating layer 31. However, theground layer may also have different shapes and/or dimensions. Forexample, the ground layer can be at least slightly larger than the radiatinglayer, such as being longer and/or wider.

Suitable dimensions of the radiation layer and the ground layer arealso here dependent on various factors, such as the operating frequency, the dielectric constant and thickness of the container material separating the 16 radiating layerfrom the ground layer, etc. ln some embodiments, the overalllength of the radiation layer and the ground layer, when arranged sequentiallyafter each other, as seen in Fig. 4a, may be in the range of 100-300 mm,such as 150-250 mm, such as 170-220 mm, and preferably in the range of180-210 mm, and more preferably in the range of 190-200 mm, such as 193mm. The width of the radiation layer and the ground layer may be in the rangeof 10-100 mm, such as 15-75 mm, such as 20-60 mm, and preferably in therange of 30-50 mm, and more preferably in the range of 35-45 mm, such as40 mm. Such dimensions make the RFID tag arrangement suitable for use atUHF frequencies.

An RFID chip 34 is provided in a similar way as in the secondembodiment discussed above. The RFID chip is arranged in a cut-out portion,which forms a non-conductive area 37 within the radiating layer 31. Twofeeding lines 35', 36' extend through the non-conductive area 37, to theterminals of the chip 34. ln this embodiment, the feed lines 35', 36' extend inopposite direction, and generally in the length direction of the radiating layer.The first feeding line 35' connects to a part of the radiating layer being at oneend, whereas the second feeding line 36' connects to a part of the radiatinglayer at another end.

The anten na of this RFID tag arrangement generally functions as apatch antenna. ln the so far discussed embodiments, the radiation layer and theground layer are formed as relatively solid areas. However, it is also feasibleto form, partly or wholly, one or both of these layers by thin strips ofconducting material, arranged to form a mesh. Such an embodiment isillustrated in Figs. 5a-b. Here, the RFID tag arrangement is similar to the onediscussed in relation to Figs. 3a-b. The difference compared to this previouslydiscussed embodiments is that both the radiation layer 31 and the groundlayer 32 are formed by thin strips, extending around the perimeters of theradiation layer and the ground layer, and with a mesh of thin strips arrangedto cross each other within the perimeters, to form a conducting mesh. lt hasbeen found that such a mesh serves the same function as a solid area, and the performance of the antenna in the RFID tag arrangement of Figs. 5a-b is 17 essentially the same as that of the antenna in the RFID tag arrangement ofFigs. 3a-b.

With reference to Fig. 6, in all the above-discussed embodiments of theRFID tag arrangement the RFID tag arrangement may comprise a dielectricsubstrate 52 on which at least one of the radiating layer and the ground layer,and preferably both, are provided, as a metal layer 51. Hereby, the RFID tagarrangement forms a label, which can be manufactured separately, and laterbe attached to the container, by inserting it into the opening and attaching iton both sides. To this end, the substrate can be provided with an adhesive53, to be connected to the interior and/or exterior side of the container. Thedielectric substrate may be realized in various ways. ln one embodiment, thedielectric separation layer is made of at least one of: paper, board, polymerfilm, textile and non-woven material.

With reference to Fig. 7, such an embodiment is illustrated where theRFID tag arrangement is arranged on one side, extending into a flap 25, overa folding line 26, so that when the flap is folded down when mounting thecontainer 2, the part of the RFID tag arrangement extending into the flapbecomes located on the inside of the container, whereas the other partremains on the outside. ln the previously discussed embodiments, the RFID tag arrangement isarranged at a side of the container, but for certain applications it is alsofeasible to arrange the RFID tags on the top or bottom of the container. Withreference to Fig. 8, such an alternative embodiment for placement of the RFID tag arrangement on the container is illustrated. Here, the RFID tag 18 arrangement 3 is arranged on one of the flaps 23 forming the closure for theaccess opening 22 of the container 2.

The radiating layer and the ground layer may be made of any materialas long as the material is conductive. The radiating layer and the ground layermay be made by the same material, but may alternatively be made ofdifferent materials. For example, the layers may be formed by aluminum, butother metals, such as silver, and alloys may also be used. For example, it isfeasible to use an alloy having a relatively low melting temperature, such asan alloy comprising tin and bismuth. Forming of the layers on the substrate,be it directly on the container or on a separate substrate, can be made invarious ways, as is per se known in the art, such as by printing withconductive ink, such as silver ink, by first providing a conductive layer on thesubstrate and subsequently removing or forming this conductive layer into thedesired shape, e.g. by means of grinding, cutting, etching or the like. ln manufacturing of the package system, there is provided a containerof a non-conductive material, and the RFID tag arrangement is integrated withthe container, by attaching a radiating layer of the RFID tag arrangement toan exterior side of the container, and attaching a ground layer to an interiorside of the container. As discussed in the foregoing, the container may beproduced and mounted first, and the RFID tag arrangement being attached tothe container when it is finished. Alternatively, the RFID tag arrangement maybe attached to the container when it is not fully mounted, or even prior tomounting, such as by providing the RFID tag arrangement to the substrateforming the container even prior to mounting, or even prior to forming theblank.

To evaluate the new package system, a number of experimental testsand simulations have been performed. ln the simulation tests, RFID tag arrangements were attached tocardboard shipment boxes which included items packed in metallizedpackaging material. The cardboard box had the dimensions 200 x 200 x 100mm. The cardboard had a thickness of 3 mm, a dielectric constant of 2.0, and a loss tangent of 0.02. 19 As a reference, a high performance, state of the art, RFID tag wasused. This RFID tag was a Stora Enso Bumper standard tag, which iscommercially available.

The reading range was measured, and the result is shown in Fig. 9. Ascan be seen, the reading range is severely distorted by the metallic content ofthe container, and in the frequency range between 0.8-1.0 GHz, i.e. in theUHF range, the reading range is only close to 1 m, and at best close to 2 m.This is far from sufficient for most applications. ln another experimental simulation, the same cardboard box was used with an antenna in accordance with the embodiment discussed in relation to Figs. 2a-c. The result is illustrated in Fig. 10. Here, a essä; reading range is achieved. Within the entire measured frequency range, this antenna performs better than the reference. ln particular in therange of 0.89-095 0.92 GHz, the reading range is above 10 m. the reading range is above 4 m, and as best, at ln another experimental simulation, the same cardboard box was usedwith antennas in accordance with the embodiments discussed in relation toFigs. 3a-b (PIFA), Figs. 4a-b (Patch) and Figs. 5a-b (PIFA Mesh). The resultis illustrated in Fig. 11. As can be seen, all of the antennas have muchimproved reading ranges compared to the reference. Within the entiremeasured frequency range, these antennas perform better than thereference. ln particular, the Patch antenna has a reading range exceeding 4m at a frequency range of 0.86-1.0 GHz, and a maximum reading range ofmore than 15 m, the PIFA antenna has a reading range exceeding 4 m at afrequency range of 0.85-0.95 GHz, and a maximum reading range of close to11 m, and the PIFA Mesh antenna has a reading range exceeding 4 m at afrequency range of 0.83-9.00 GHz, and a maximum reading range exceeding10 m.

Thus, all of the measured embodiments of the RFID tag arrangementshave a far better performance in this context than the reference. The offset infrequency tuning between the different embodiments can be easilycompensated in antenna design. The Patch tag shows better a performance than the PIFA tags, which is probably due to improved directivity/gain.

The person skilled in the art realizes that the present invention is notlimited to the above-described embodiments. For example, the generalantenna design may be varied in many ways, as is per se well-known in theart. For example, the radiating layer may be formed as a solid part, as ameshed type par, or as a combination of these. Further, both the radiatinglayer and the ground layer may be shaped differently than in the above- discussed embodiments, and the feeding, så g, may also have othershapes. The RFID tag arrangement may further be adapted for differentoperational frequencies.

Further, the RFID chip may be arranged on different places in relationto the antenna, such as centrally on the radiating layer, towards one of theedges of the radiating layer, close to a bridge connecting the radiating layer tothe ground layer, outside the radiating layer, such as on one side of theradiating layer, or between the radiating layer and the ground layer, or evenon the ground layer. The feeding line may be arranged adjacent to one side ofthe radiating layer, or within the radiating layer, in a cut-out portion of thesame. An end of the feeding line may be connected to a central part of theradiating layer, or to a part in the vicinity of one of the edges of the radiatinglayer, or to an edge close to the ground layer.

Such and other obvious modifications must be considered to be withinthe soope of the present invention, as it is defined by the appended claims. ltshould be noted that the above-described embodiments illustrate rather thanlimit the invention, and that those skilled in the art will be able to design manyalternative embodiments without departing from the scope of the appendedclaims. ln the claims, any reference signs placed between parentheses shallnot be construed as limiting to the claim. The word “comprising“ does notexclude the presence of other elements or steps than those listed in theclaim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.

Claims

1. A package system (1) comprising: a container (2) for storing goods and made of a non-conductivematerial; an RFID tag arrangement (3) integrated with the container, wherein theRFID tag arrangement comprises a radiating layer (31) attached to an exteriorside of the container, a ground layer (32) attached to an interior side of thecontainer, the ground layer and the radiating layer being parallel to each otherand at least partly overlapping when seen from a direction perpendicular tosaid layers, the ground layer (32) and the radiating layer (31) thereby beingseparated by the non-conductive material of the container, and an RFID chip(34) connected to the radiating layer (31 ).

2. The package system of claim 1, wherein the container (2)comprises an opening (21), and wherein the ground layer (32) and theradiating layer (31) are arranged to abut the opening (21), and wherein theRFID tag arrangement (3) further comprises a bridge (33) connecting theground layer (32) and the radiating layer (31) over the opening.

3. The package system of claim 2, wherein the radiating layer (31)and the ground layer (32) of the RFID tag arrangement (3) form a planarinverted-F antenna.

4. The package system of claim 2 or 3, wherein the radiating layer(31) has a resonant length of essentially a quarter of a wavelength at anoperating frequency of the RFID tag arrangement (3).

5. The package system of claim 1, wherein the RFID tagarrangement (3) is free from any galvanic connection between the radiatinglayer (31) and the ground layer (32).

6. The package system of claim 5, wherein the radiating layer (31)and the ground layer (32) of the RFID tag arrangement (3) form a patchantenna.

7. The package system of claim 5 or 6, wherein the radiating layer(31) has a resonant length of essentially half a wavelength at an operatingfrequency of the RFID tag arrangement (3).

8. The package system of any one of the preceding claims,wherein the radiating layer (31) has width and length dimensions which arethe same as, or smaller than, the width and length dimensions of the groundlayer (32).

9. The package system of any one of the preceding claims,wherein the radiating layer (31) is arranged totally within the bounds of theground layer (32), when seen from a direction perpendicular to said layers. 10.wherein the RFID tag arrangement (3) further comprises at least one feedingline (35, 35', 36, 36'), connecting a terminal of the RFID chip (34) to adetermined position of the radiating layer (31 ). 11.wherein the non-conductive material is at least one of cardboard, plastic and

10. The package system of any one of the preceding claims,

11. The package system of any one of the preceding claims, wood.12.wherein the non-conductive material is cardboard, and preferably at least one

12. The package system of any one of the preceding claims, of paperboard and corrugated fiberboard.

13. The package system of any one of the preceding claims,wherein the container (2) is a packaging box.

14. The package system of any one of the preceding claims, wherein the non-conductive material of the container (2) separating theradiating layer (31) and the ground layer (32) has a thickness in the range of1-10 mm, and preferably in the range of 2-7 mm, and most preferably in therange of 2-5 mm.

15.wherein the RFID tag arrangement (3) comprises a dielectric substrate (52) The package system of any one of the preceding claims, on which at least one of said radiating layer (31) and said ground layer (32)are provided, said substrate being connected to the interior and/or exteriorside of the container by an adhesive.

16.wherein at least one of the radiating layer (31) and the ground layer (32) are The package system of any one of the preceding claims, printed directly on the interior and/or exterior surface of the container (2).

17.wherein at least one of said radiating layer (31) and said ground layer (32) are The package system of any one of the preceding claims, formed with an essentially solid conductive material extending over the outerbounds of the layer.

18.wherein at least one of said radiating layer (31) and said ground layer 32) are The package system of any one of the preceding claims, formed with an solid conductive material extending along the perimeter of theouter bounds of the layer, but with a plurality of non-conductive areas (37) inthe interior of the layer.

19.wherein the at least one of said radiating layer (31) and said ground layer (32) The package system of any one of the preceding claims, comprises a mesh formed by conductive strips, and with non-conductiveareas (37) between said strips.

20. The package system of any one of the preceding claims,wherein the RFID tag arrangement (3) is configured for operation at afrequency within the range of 860-960 MHz.

21. A method for manufacturing a package, comprising: providing a container (2) for storing goods and made of a non-conductive material; integrating an RFID tag arrangement (3) with the container (2), byattaching a radiating layer (31) of the RFID tag arrangement (3) to an exteriorside of the container, and attaching a ground layer (32) to an interior side ofthe container, the ground layer (32) and the radiating layer (31) being parallelto each other and at least partly overlapping when seen from a directionperpendicular to said layers, the ground layer (32) and the radiating layer (31)thereby being separated by the non-conductive material of the container (2),and by connecting an RFID chip (34) to the radiating layer.