WO2021224769A1

WO2021224769A1 - Package system with self-grounded rfid tag arrangement

Info

Publication number: WO2021224769A1
Application number: PCT/IB2021/053698
Authority: WO
Inventors: Lauri Huhtasalo; Ilkka YLI-PELTOLA
Original assignee: Digital Tags Finland Oy
Current assignee: Digital Tags Finland Oy
Priority date: 2020-05-04
Filing date: 2021-05-04
Publication date: 2021-11-11
Anticipated expiration: 2022-11-04
Also published as: SE544137C2; SE2050512A1; FI130849B1; FI20226065A1

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 ARRANGEMENT

The present invention is related to a package system with a self- grounded radio frequency identification (RFID) tag arrangement. The invention further relates to a manufacturing method for producing such a package system.

Backaround

RFID tags are nowadays used more and more frequently, and for a wide variety of applications, such as in smart labels/tags. The RFID tag is conventionally arranged as a flat configured transponder, e.g. arranged under a conventional print-coded label, and includes a chip and an antenna. The labels/tags are often made of paper, fabric or plastics, and are normally prepared with the RFID inlays laminated between a carrier and a label media, e.g. for use in specially designed printer units. Smart labels offer advantages over conventional barcode labels, such as higher data capacity, possibility to read and/or write outside a direct line of sight, and the ability to read multiple labels or tags at one time.

It is also known to incorporate RFID labels directly in a packaging material, to form so-called intelligent packaging products.

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

However, a problem with most commercially available RFID tag antennas when arranged on a package is that the radiation properties may be severely distorted by the content of the package. Packaging like corrugated board shipment boxes are often used to transport items which are not compatible with conventional RFID tags. Such items may be metallic or packed in metallic primary packaging, or may contain liquid. For example, this relates 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 to identify also such packages with RFID systems.

Typical low-cost RFID labels are not able to be interrogated well when applied directly or very close to metallic or liquid objects. Sometimes in the shipment box, there is a space of free air at the top. Then a standard UHF RFID tag can be applied to such position in the package, where there is air behind the corrugated board material. But very often, to save transport costs, the package is completely full of the items. In this case, standard UHF RFID tags will not work properly to identity the packages. Further, the placement of the RFID tag in relation to the goods in the packages are often difficult to control properly, making it difficult to use standard RFID tags even when there are empty spaces in the packages.

To this end, it has been known to use foam tags with FIFA antennas. The FIFA antennas are formed into a folded structure, and insulative material such as plastic foam is inserted between the folded parts. The FIFA tags are typically injection molded into a protective molded envelope. However, a drawback with such RFID tags is that they are very costly to produce. In addition, these RFID tags are relatively thick, typically with a thickness of 6-12 mm, making them unsuitable for use for many packages, and also increases the risk that the tags fall of or become damaged during handling of the package. It is also difficult to make such RFID tags recyclable, thereby adding to the overall handling costs.

It has also been known to use RFID tags which are arranged to protrude out from the packages, so called flag tags. However, when shipment boxes are palletized, there is normally no space for such protruding tags. Further, there is here an even greater risk that the tags become damaged during handling, both during palletizing, and handling before and after that.

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

It is therefore an object of the present invention to provide a package system including an RFID tag arrangement and a manufacturing method for such a package, which alleviates at least part of the above-discussed problems, and at least partially address one or more of the above-mentioned needs.

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

According to a first aspect of the invention there is provided a package system comprising: a container for storing goods and made of a non-conductive material; an RFID tag arrangement integrated with the container, wherein the RFID tag arrangement comprises a radiating layer attached to an exterior side of the container, a ground layer 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 and the radiating layer thereby being separated by the non-conductive material of the container, and an RFID chip connected to the radiating layer.

The container may e.g. be arranged to contain goods which attenuates or distorts electromagnetic wave signals at frequencies where the RFID tag is arranged to operate. The RFID tag may e.g. be configured for operation at a frequency within the range of 860-960 MHz. Such goods may e.g. be metallic objects, or objects enclosed in metallic or partly metallic packages, such as cigarette packages, comprising aluminum wrappings. The goods may also contain liquid.

The RFID tag arrangement is preferably configured for operation at the UHF 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 of the container.

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

Further, since the antenna uses a part of the container as separation layer between the radiation layer and the ground layer, the RFID tag arrangement is very thin, and also very cost-efficient to produce. The low costs are associated with the few parts needed to form the antenna, and that already existing material, i.e. the material of the container, is used also as a part of the antenna. In addition, the antenna is easy to manufacture and to mount on the container. Compared to presently used FIFA RFID tags, the RFID tag of the present invention can be produced to a cost which is at least 10 times lower, and possibly up to about 100 times lower.

Since the RFID tag of the present invention can be made very thin, and very well integrated in the package, the risk of damages and the like to the RFID tag becomes very low. Hence, the package system becomes very robust, with very low risk of the RFID tag becoming inoperative during handling and use of the package. Thus, adequate RFID communication can be 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 package system can easily be made recyclable, without the need to detach the RFID tag arrangement.

In one embodiment, the container comprises an opening, wherein the ground layer and the radiating layer are arranged to abut the opening, and wherein the RFID tag arrangement further comprises a bridge connecting the ground layer and the radiating layer over the opening. Thus, the radiating layer 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 its plane generally perpendicular to the planes of the ground layer and the radiating layer. Hereby, the radiating layer and the ground layer of the RFID tag arrangement preferably form a planar inverted-F antenna (FIFA). 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 the wavelength would be about 8 cm. Thus, the RFID tag with this antenna can be made relatively compact also in the width and length direction.

With the FIFA structure, electromagnetic fields concentrate between the radiator, i.e. the radiating layer, and antenna ground plane, i.e. the ground layer, in a controlled manner. The antenna is tolerant and insensitive to materials behind the antenna ground plane. Also, metal content within the container 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 and folded over the wall at the sides of the opening. The opening may e.g. be a separately made opening, made specifically for this purpose. However, it is also feasible to use already existing opening, i.e. openings provided for other reasons, such as opening provided at the top of the container, or handle openings arranged at the sides of the container.

In an alternative embodiment, the RFID tag arrangement is free from any galvanic connection between the radiating layer and the ground layer. Hereby, the radiating layer and the ground layer of the RFID tag arrangement preferably form a patch antenna. Here, the radiating layer preferably has a resonant length of essentially half 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 half wavelength would be about 16 cm. Thus, the RFID tag with this antenna is less compact than the first discussed embodiment but is still sufficiently compact in the width and length direction to fit most types of containers.

In this embodiment, the ground layer and the radiating layer may still be arranged adjacent to an opening of the package. The ground layer and the radiating layer may e.g. be provided on a substrate, which is adhered to the container by folding it over the opening, in same way as for the antenna of the first embodiment. However, since there is no galvanic connection between the 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 layer and radiation layer is maintained.

In both embodiments of the antenna, the antenna can be made very thin, thus hardly adding any noticeable thickness or weight to the container.

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

The radiating layer may have width and length dimensions which are the same as, or smaller than, the width and length dimensions of the ground layer. Thus, the dimensions of the radiating layer may be essentially the same as the dimensions of the ground layer. Alternatively, the dimensions of the ground layer may be somewhat greater than the dimensions of the radiating layer, or even significantly greater. Put differently, the radiating layer may be arranged totally within the bounds of the ground layer, when seen from a direction perpendicular to said layers.

The RFID tag arrangement may further comprise at least one feeding line, connecting a terminal of the RFID chip to a determined position of the radiating layer. The feeding line may e.g. connect the RFID chip terminal to a position relatively centrally in the radiating layer, in the vicinity of one of the ends of the radiating layer, or the like. In an embodiment where the radiation layer is galvanically connected to the ground layer, such as in the PIFA embodiment, the feeding line may connect the terminal of the chip to a position of the radiation layer being distant from and essentially opposite to the connection to the ground layer, and the other terminal of the chip may be connected to the ground layer. In an embodiment where the radiation layer is galvanically separated from the ground layer, such as in the patch antenna embodiment, two feeding lines may be provided, connecting the terminals of the 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 is also suitable for forming a container. In 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 paperboard and corrugated fiberboard. Cardboard here generally indicates a heavy- duty paper-based products having greater thickness and superior durability or other specific mechanical attributes to paper; such as foldability, rigidity and impact resistance. Cardboard includes paperboard, which is thick sheets of paper-based material, typically of a thickness exceeding 0.25 mm, and corrugated fiberboard, which is a combination of paperboards, such as a combination 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 generally rectangular cross-section and all sides flat, such as a folding carton, a bulk box or a corrugated box. However, the cross-section need not be rectangular, but rounded or beveled edges may be provided, and also elongated, round or oval 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 as being domed.

The non-conductive material of the container separating the radiating layer 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 of electromagnetic 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 shapes and dimensions, as is per se known in the art. For example, the radiation layer may extend in a generally linear direction, or may extend in a non-linear way, and may have a uniform width, or a width varying over the length. Parts of the antenna may also be folded or curved, thereby extending in two or more directions.

In one embodiment, the RFID tag arrangement comprises a dielectric substrate on which at least one of said radiating layer and said ground layer are 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. In one embodiment, the dielectric separation layer is made of at least one of: paper, board, polymer film, textile and non-woven material.

The dielectric substrate may have a thickness in the range of 20-300 pm, and preferably in the range 50-200 pm, and more preferably in the range 50-150 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 the ground layer may be printed directly on the interior and/or exterior surface of the container. In such an embodiment, the printing can be made on different sides of a substrate forming the container. Alternatively, the printing can be made on a single side, and extending over a folding line into a flap, arranged to be downfolded when the container is mounted.

At least one of the radiating layer and the ground layer may be formed with an essentially solid conductive material extending over the outer bounds of the layer. In such an embodiment, the radiating layer forms an outer perimeter, and is filled, or essentially, filled with conductive material inside this perimeter. In one embodiment, the radiating layer is formed by such a solid shape. In one embodiment, the ground layer is formed by such a solid shape. In one embodiment, both the radiating layer and the ground layer are formed by such a solid shape.

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

The RFID tag arrangement may be either passive, i.e. powered by a reader’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, if the material is conductive. The radiating layer and the ground layer may be made by the same material but may alternatively be made of different materials. For example, the layers may be formed by aluminum, but other 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, such as by printing with conductive ink, such as silver ink, by first providing a conductive layer on the substrate and subsequently removing or forming this conductive 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 a method for manufacturing a package, comprising: providing a container for storing goods and made of a non-conductive material; integrating an RFID tag arrangement with the container, by attaching a radiating layer of the RFID tag arrangement to an exterior side of the container, and attaching a ground layer 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 and the radiating layer thereby being separated by the non- conductive material of the container, and by connecting an RFID chip to the radiating layer.

In accordance with this aspect, similar features and advantages as discussed in the foregoing, in relation to the first aspect, may be obtained.

It will be appreciated that the above-mentioned detailed structures and advantages of the first aspect of the present invention also apply to the further aspects of the present invention.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. Brief description of the drawings

For exemplifying purposes, the invention will be described in closer detail in the following with reference to embodiments thereof illustrated in the attached drawings, wherein:

Fig. 1 a and 1 b are illustrations of a package system in accordance with an embodiment of the invention, where Fig. 1 is a perspective side view of the package 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 a package system in accordance with an embodiment of the invention, wherein Fig. 2a is a perspective view of the RFID tag arrangement, Fig. 2b is a perspective view illustrating the RFID tag arrangement when attached to a container, and Fig. 2c is a cross-sectional view of the RFID tag arrangement when attached to a container;

Figs. 3a-b illustrate an RFID tag arrangement for use in a package system 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, prior to folding, and Fig. 3b is perspective view of the RFID tag arrangement in a folded state;

Fig. 4a-b illustrate an RFID tag arrangement for use in a package system 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, prior to folding, and Fig. 4b is perspective view of the RFID tag arrangement in an attached, folded state;

Figs. 5a-b illustrate an RFID tag arrangement for use in a package system in accordance with yet another embodiment of the present invention, wherein Fig. 5a shows a perspective view of the RFID tag arrangement in an attached, folded state, without any container, and Fig. 5b shows the same RFID tag arrangement as in Fig. 5a, attached to a container wall;

Fig. 6 is a cross-sectional illustration of a layered RFID tag arrangement structure, in accordance with an embodiment of the present invention;

Figs. 7 and 8 are perspective views of alternative package systems, in accordance 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; and

Figs. 10 and 11 are diagrams illustrating the reading range for the RFID tag arrangements of Figs. 2a-c, 3a-b, 4a-b and 5a-b.

Detailed description of preferred embodiments In the following detailed description preferred embodiments of the invention will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. It may also be noted that, for the sake of clarity, the dimensions of certain components, parts and elements illustrated in the drawings may differ from the corresponding dimensions in real-life implementations of the invention, such as the thickness of various layers, the relative dimensions of the different antenna parts, etc.

With reference to figs. 1a and 1b, an embodiment of a package system 1 comprises a container 2 for storing goods and made of a non-conductive material. The container can contain any types of goods and items but is particularly suited to contain goods which attenuates or distorts electromagnetic wave signals at frequencies where an RFID tag is arranged to operate. The RFID tag may e.g. be configured for operation at a frequency within the range of 860-960 MHz. Such goods may e.g. be metallic objects, or objects enclosed in metallic or partly metallic packages, such as cigarette packages, comprising aluminum wrappings. The goods may also contain liquid or foodstuff.

The non-conductive material may be any dielectric material which is also suitable for forming a container, such as cardboard, plastic and/or wood. Preferably, the non-conductive material is cardboard, and preferably at least one 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 generally rectangular cross-section and all sides flat, as in the illustrative example of Fig. 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 beveled edges may be provided, and also elongated, round or oval 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 as being domed. The container may have an opening 21 in a sidewall, e.g. for use as a handle. 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 unpacking. The access opening 22 may be closed with a lid, or by one or two flaps 23, 24, which may be foldable to close the access opening.

As best seen in Fig. 1b, the container, when packed, may be filled with goods 4, such that hardly any free space remains in the container. The goods may be of a type that distorts radio frequency communication, such as being of 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 tag arrangement will be discussed in more detail in the following.

In a first embodiment of the RFID tag arrangement, as illustrated in Figs. 2a-c, the RFID tag comprises a radiating layer 31 , attached to an external side of the container, and a ground layer 32 attached to an internal side of the container. A bridge 33 galvanically connects the radiating layer and the ground layer.

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

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

The radiating layer 31 and the ground layer 32 are further preferably arranged to at least partly overlap each other when seen from a direction perpendicular to these layers, i.e. when seen from the second direction. In the illustrative example, there is essentially a complete overlap. The ground layer 31 and the radiating layer 32 are hereby separated by the non-conductive material of the container 2. Thus, no additional insulation between the two layers are needed, and the non-conductive material of the container serves the dual purposes of both forming the container and providing insulation between the radiation layer and the ground layer.

In the illustrative example, the radiating layer 31 generally has the shape of an elongate rectangle, having one of its short sides abutting the opening and being connected to the bridge 33. However, many other shapes are also feasible. The ground layer 32 here has shapes and dimensions generally corresponding to those of the radiating layer 31. However, the ground layer may also have different shapes and/or dimensions. For example, the ground layer can be at least slightly larger than the radiating layer, such as being longer and/or wider.

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

An RFID chip 34 is further provided. One terminal of the RFID chip is connected to the radiating layer 31 , preferably through a feeding line 35, so that 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 side opposite to the bridge than to the short side connected to the bridge. In some embodiments, the connection can be made to a position in the vicinity of the end opposite to the bridge.

Another terminal of the RFID chip 34 may be connected to the ground layer, preferably through a feeding line 36, so that 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 side opposite to the bridge than to the short side connected to the bridge. In some embodiments, the connection can be made to a position in the vicinity of the end opposite to the bridge. In this embodiment, the RFID chip is arranged between the radiating layer 31 and the ground layer 32, but may also be placed in other positions.

The antenna of this RFID tag arrangement generally functions as a FIFA antenna.

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 to Figs. 2a-c and is attached to the container in the same way. Thus, apart from the details specified in the following, the RFID tag arrangement of this embodiment is constituted in the same way as the one previously discussed.

In this embodiment, the RFID chip 34 is arranged on the radiating layer 31 , and e.g. relatively centrally on this layer. However, it may also be arranged more or less displaced towards one or two of the sides.

Suitable dimensions of the radiation layer and the ground layer are dependent on various factors, such as the operating frequency, the dielectric constant and thickness of the container material separating the radiating layer from the ground layer, etc. In some embodiments, the overall length of the radiation layer and the ground layer may be in the range of 20-200 mm, such as 50-150 mm, such as 80-120 mm, and preferably in the range of 90-110 mm, and more preferably in the range of 95-105 mm, such as 98 mm. The width 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 range of 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 UHF frequencies.

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. In this embodiment, a first of the feeding lines 35’ extends away from the bridge 33, and a second of the feeding lines 36’ extends towards the bridge 33. The first feeding line 35’ connects to a part of the radiating layer being at a distance from the bridge, and at, or in the vicinity of, the end opposite to the bridge. The second feeding line 36’ connects to a part of the radiating layer closer to the bridge, and at, or in the vicinity of the end connecting to the bridge.

The antenna of this RFID tag arrangement also generally functions as a FIFA antenna.

In yet another embodiment of the RFID tag arrangement, as illustrated in Figs. 4a-b, the RFID tag also comprises a radiating layer 31, attached to an external side of the container, and a ground layer 32 attached to an internal side of the container. However, in this embodiment there is no bridge connecting the radiating layer and the ground layer, and the layers are galvanically separated.

When arranged on the container, the radiating layer 31 and the ground layer 32 may even in this embodiment be arranged so that one side of each layer buts an opening of the container, such as the handle opening 21. However, since there is no bridge formed between the layers, the layers may here also be arranged at some distance from the opening, or even at places of the container not having any opening.

Also, in this embodiment, the radiating layer 31 and the ground layer are generally parallel to each other, and extend in a first direction, which is also parallel to the side of the container containing the opening. The radiating layer 31 and the ground layer 32 are further preferably arranged to at least partly overlap each other when seen from a direction perpendicular to these layers, i.e. when seen from a direction perpendicular to the first direction. In the illustrative example, there is essentially a complete overlap.

Similar to the first discussed embodiment, the ground layer 31 and the radiating layer 32 are here separated by the non-conductive material of the container 2.

Suitable dimensions of the radiation layer and the ground layer are also here dependent on various factors, such as the operating frequency, the dielectric constant and thickness of the container material separating the radiating layer from the ground layer, etc. In some embodiments, the overall length of the radiation layer and the ground layer, when arranged sequentially after 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 of 180-210 mm, and more preferably in the range of 190-200 mm, such as 193 mm. The width 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 range of 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 UHF frequencies.

An RFID chip 34 is provided in a similar way as in the second embodiment discussed above. The RFID chip is arranged in a cut-out portion, which forms a non-conductive area 37 within the radiating layer 31. Two feeding lines 35’, 36’ extend through the non-conductive area 37, to the terminals of the chip 34. In this embodiment, the feed lines 35', 36' extend in opposite 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 one end, whereas the second feeding line 36’ connects to a part of the radiating layer at another end.

The antenna of this RFID tag arrangement generally functions as a patch antenna.

In the so far discussed embodiments, the radiation layer and the ground layer are formed as relatively solid areas. However, it is also feasible to form, partly or wholly, one or both of these layers by thin strips of conducting material, arranged to form a mesh. Such an embodiment is illustrated in Figs. 5a-b. Here, the RFID tag arrangement is similar to the one discussed in relation to Figs. 3a-b. The difference compared to this previously discussed embodiments is that both the radiation layer 31 and the ground layer 32 are formed by thin strips, extending around the perimeters of the radiation layer and the ground layer, and with a mesh of thin strips arranged to cross each other within the perimeters, to form a conducting mesh. It has been 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 essentially the same as that of the antenna in the RFID tag arrangement of Figs. 3a-b.

With reference to Fig. 6, in all the above-discussed embodiments of the RFID tag arrangement the RFID tag arrangement may comprise a dielectric substrate 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 tag arrangement forms a label, which can be manufactured separately, and later be attached to the container, by inserting it into the opening and attaching it on both sides. To this end, the substrate can be provided with an adhesive 53, to be connected to the interior and/or exterior side of the container. The dielectric substrate may be realized in various ways. In one embodiment, the dielectric separation layer is made of at least one of: paper, board, polymer film, textile and non-woven material.

With reference to Fig. 7, such an embodiment is illustrated where the RFID tag arrangement is arranged on one side, extending into a flap 25, over a folding line 26, so that when the flap is folded down when mounting the container 2, the part of the RFID tag arrangement extending into the flap becomes located on the inside of the container, whereas the other part remains on the outside. In the previously discussed embodiments, the RFID tag arrangement is arranged at a side of the container, but for certain applications it is also feasible to arrange the RFID tags on the top or bottom of the container. With reference to Fig. 8, such an alternative embodiment for placement of the RFID tag arrangement on the container is illustrated. Here, the RFID tag arrangement 3 is arranged on one of the flaps 23 forming the closure for the access opening 22 of the container 2.

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 layer may be made by the same material but may alternatively be made of different materials. For example, the layers may be formed by aluminum, but other metals, such as silver, and alloys may also be used. For example, it is feasible to use an alloy having a relatively low melting temperature, such as an 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 in various ways, as is per se known in the art, such as by printing with conductive ink, such as silver ink, by first providing a conductive layer on the substrate and subsequently removing or forming this conductive layer into the desired shape, e.g. by means of grinding, cutting, etching or the like.

In manufacturing of the package system, there is provided a container of a non-conductive material, and the RFID tag arrangement is integrated with the container, by attaching a radiating layer of the RFID tag arrangement to an exterior side of the container, and attaching a ground layer to an interior side of the container. As discussed in the foregoing, the container may be produced and mounted first, and the RFID tag arrangement being attached to the container when it is finished. Alternatively, the RFID tag arrangement may be attached to the container when it is not fully mounted, or even prior to mounting, such as by providing the RFID tag arrangement to the substrate forming the container even prior to mounting, or even prior to forming the blank.

To evaluate the new package system, a number of experimental tests and simulations have been performed. In the simulation tests, RFID tag arrangements were attached to cardboard shipment boxes which included items packed in metallized packaging material. The cardboard box had the dimensions 200 x 200 x 100 mm. The cardboard had a thickness of 3 mm, a dielectric constant of 2.0, and a loss tangent of 0.02.

As a reference, a high performance, state of the art, RFID tag was used. This RFID tag was a Stora Enso Bumper standard tag, which is commercially available.

The reading range was measured, and the result is shown in Fig. 9. As can be seen, the reading range is severely distorted by the metallic content of the container, and in the frequency range between 0.8-1.0 GHz, i.e. in the UHF 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.

In 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 much-improved reading range is achieved. Within the entire measured frequency range, this antenna performs better than the reference. In particular in the range of 0.89-095 GHz, the reading range is above 4 m, and as best, at 0.92 GHz, the reading range is above 10 m.

In another experimental simulation, the same cardboard box was used with antennas in accordance with the embodiments discussed in relation to Figs. 3a-b (FIFA), Figs. 4a-b (Patch) and Figs. 5a-b (FIFA Mesh). The result is illustrated in Fig. 11. As can be seen, all the antennas have much improved reading ranges compared to the reference. Within the entire measured frequency range, these antennas perform better than the reference. In particular, the Patch antenna has a reading range exceeding 4 m at a frequency range of 0.86-1.0 GHz, and a maximum reading range of more than 15 m, the FIFA antenna has a reading range exceeding 4 m at a frequency range of 0.85-0.95 GHz, and a maximum reading range of close to 11 m, and the FIFA Mesh antenna has a reading range exceeding 4 m at a frequency range of 0.83-9.00 GHz, and a maximum reading range exceeding 10 m. Thus, all the measured embodiments of the RFID tag arrangements have a far better performance in this context than the reference. The offset in frequency tuning between the different embodiments can be easily compensated in antenna design. The Patch tag shows better a performance than the FIFA tags, which is probably due to improved directivity/gain.

The person skilled in the art realizes that the present invention is not limited to the above-described embodiments. For example, the general antenna design may be varied in many ways, as is per se well-known in the art. For example, the radiating layer may be formed as a solid part, as a meshed type par, or as a combination of these. Further, both the radiating layer and the ground layer may be shaped differently than in the above- discussed embodiments, and the feeding, etc., may also have other shapes. The RFID tag arrangement may further be adapted for different operational frequencies.

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

Such and other obvious modifications must be considered to be within the scope of the present invention, as it is defined by the appended claims. It should be noted that the above-described embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting to the claim. The word “comprising” does not exclude the presence of other elements or steps than those listed in the claim. 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-conductive material; an RFID tag arrangement (3) integrated with the container, wherein the RFID tag arrangement comprises a radiating layer (31) attached to an exterior side of the container, 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) thereby being separated 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 the radiating layer (31) are arranged to abut the opening (21), and wherein the RFID tag arrangement (3) further comprises a bridge (33) connecting the ground 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 planar inverted-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 an operating frequency of the RFID tag arrangement (3).

5. The package system of claim 1 , wherein the RFID tag arrangement (3) is free from any galvanic connection between the radiating layer (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 patch antenna.

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 operating frequency 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 are the same as, or smaller than, the width and length dimensions of the ground layer (32).

9. The package system of any one of the preceding claims, wherein the radiating layer (31) is arranged totally within the bounds of the ground layer (32), when seen from a direction perpendicular to said layers.

10. The package system of any one of the preceding claims, wherein the RFID tag arrangement (3) further comprises at least one feeding line (35, 35’, 36, 36’), connecting a terminal of the RFID chip (34) to a determined position of the radiating layer (31).

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

12. The package system of any one of the preceding claims, wherein the non-conductive material is cardboard, and preferably at least one 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 the radiating layer (31 ) and the ground layer (32) has 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.

15. The package system of any one of the preceding claims, wherein the RFID tag arrangement (3) comprises a dielectric substrate (52) 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 exterior side of the container by an adhesive.

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

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

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

19. The package system of any one of the preceding claims, wherein the at least one of said radiating layer (31) and said ground layer (32) comprises a mesh formed by conductive strips, and with non-conductive areas (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 a frequency 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), by attaching a radiating layer (31) of the RFID tag arrangement (3) to an exterior side of the container, and attaching a ground layer (32) to an interior side of the container, the ground layer (32) and the radiating layer (31 ) 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 ) thereby being separated by the non-conductive material of the container (2), and by connecting an RFID chip (34) to the radiating layer.