Control of RFID devices for increasing the reliability and effectiveness of RFID electronic article surveillance systems

Abstract

An RFID (radio frequency identification) device for improving the performance of an electronic article surveillance system is provided. The RFID device can be modified in any of a number of ways to reduce its peak sensitivity and increase its bandwidth, thereby stabilizing its read range. The performance of the RFID device will depend on the properties of the article with which it is associated, so that the properties of the article to which the RFID device is to be associated can be taken into account in the design of the RFID device to balance the performance of RFID devices associated with different articles at operating frequencies. By reducing the peak sensitivity and increasing the bandwidth of the RFID device in an electronic article surveillance system, the size of the transition zone between two read zones of the system can be reduced.

Description

[0001] Cross-references to related patent applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 970,913, filed on February 6, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present subject matter relates to radio frequency identification ("RFID") devices. More particularly, the present subject matter relates to controlling the read range of RFID devices to ensure the reliability and effectiveness of electronic article surveillance ("EAS") systems that use RFID devices. Background Art

[0004] In retail stores, it is important to accurately count products on display and / or in storage. In addition, it is important to have effective anti-theft systems in place. RFID tags and labels (collectively referred to herein as "RFID devices") have been employed to perform both of these functions.

[0005] The EAS system using RFID technology has two main reading zones 10, 20 (as shown in FIG. 1), each of which includes an associated RFID reader. The first reading zone 10 is the store area where products are presented to consumers (which may be referred to herein as the "inventory area"), while the second reading zone 20 is the store exit area (which may be referred to herein as the "detection zone") where any RFID device that has not been properly deactivated can be detected to trigger some type of alarm indicating that someone is trying to steal the product. When the customer correctly purchases the product, the cashier removes or deactivates the RFID device associated with the product. If the RFID device is not removed or deactivated, the RFID reader will read the device and cause an alarm or other warning to be triggered in the detection zone 20.

[0006] Although the above-described system is relatively common, there are certain disadvantages. When using RFID devices / systems for EAS systems, a common problem is that the read range of the RFID device may be large enough in some cases that an RFID device in the inventory area 10 can be read in the detection area 20, or vice versa. In order to reduce this risk, a transition zone 30 is often provided between the inventory area 10 and the detection area 20 to physically separate the two reading areas. However, because different RFID devices have greater sensitivity at the operating frequency and / or different items have different effects on the performance of the associated RFID device, it is necessary to make the transition zone 30 relatively large, resulting in a large portion of unused space in the retail store for displaying inventory (i.e., a reduced inventory area). Therefore, it would be advantageous to provide an RFID device that is configured in a manner that allows the size of the transition zone 30 to be reduced. Summary of the invention

[0007] The subject matter of the present invention has several aspects that can be implemented individually or together in the devices, systems and methods described and claimed below. These aspects can be used alone or in combination with other aspects of the subject matter described herein, and the common description of these aspects is not intended to exclude the use of these aspects alone or to claim these aspects alone or in different combinations that can be illustrated in the attached invention claims.

[0008] In one aspect, a method of manufacturing an RFID device for an RFID-enabled electronic article surveillance system (hereinafter referred to as an "EAS system") is disclosed. In some embodiments, the manufacturing method includes providing an RFID device having a relatively low radio frequency (RF) conductivity. The method of manufacturing the RFID device includes providing an RFID chip and an antenna and coupling the RFID chip to the antenna. In some embodiments, the antenna of the RFID device is configured with a relatively low RF conductivity to reduce the peak sensitivity of the RFID device and increase the bandwidth of the RFID device.

[0009] In yet another aspect, an RFID-enabled EAS system includes at least one RFID device having an antenna. The EAS system further includes a first read zone and a second read zone, wherein a relatively smaller transition zone is positioned between the first read zone and the second read zone. The transition zone is defined as being smaller than the first read zone and the second read zone by reducing the RF conductivity of the antenna of the at least one RFID device to reduce the peak sensitivity of the at least one RFID device and increase the bandwidth of the at least one RFID device. The reduction in peak sensitivity of the at least one RFID device ensures that the RFID device is not read / detected in the first read zone when it is physically present in the second read zone, and is not read / detected in the second read zone when it is physically present in the first read zone. The reduction in peak sensitivity and the increase in bandwidth of the at least one RFID device ensure that the at least one RFID device has optimal performance within the first read zone and the second read zone of the EAS system, while also ensuring that the RFID device is not accidentally read in the first read zone or the second read zone. Therefore, the conductivity of each RFID antenna is selected in a manner that reduces the peak sensitivity without compromising the performance of the antenna in the first read zone and the second read zone. The reduction in peak sensitivity of the RFID device also directly affects the size of the transition zone of the EAS system. Specifically, since the reduction in the peak sensitivity of the at least one RFID device ensures that the at least one RFID device is not accidentally read, this naturally leads to a reduction in the size of the transition zone of the EAS system. This optimized performance of the at least one RFID device of the EAS system improves the overall reliability and effectiveness of the EAS system while providing the additional advantage of a reduced size of the transition zone in the EAS system.

[0010] In another aspect, a method for maximizing the performance of an RFIF-enabled EAS system is disclosed, the system comprising a plurality of RFID devices. This method involves manufacturing RFID devices having different configurations for marking different items configured to be monitored by the same EAS system. For example, a first RFID device is manufactured to include a first RFID chip and a first antenna. The first antenna is coupled to the first RFID chip to define a first RFID device configured to be associated with a first item. Further, a second RFID device having a second RFID chip and a second antenna is provided, wherein the second RFID chip is coupled to the second RFID antenna. The second RFID device is configured to be associated with a second item. The two items are configured to affect the performance of the associated RFID device in different ways, wherein the two antennas are configured differently based at least in part on the properties of the first item and the second item to have similar read ranges at a predetermined frequency. In one embodiment, the second antenna is configured to have a larger size than the first antenna, and the second antenna is formed of a second material having a lower conductivity than the first material forming the first antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is an illustrative representation of a conventional electronic article surveillance system using RFID devices;

[0012] FIG. 2A is a graph showing the relationship between frequency and read range for an RFID device having a conventional antenna;

[0013] Figure 2B is a graph showing a relationship between frequency and read range of an RFID device having an antenna with lower conductivity according to an aspect of the present invention;

[0014] Figure 3 is a graph showing the relationship between frequency and read range for an RFID device having an antenna with different conductivity levels;

[0015] Figure 4 is a top plan view of an exemplary embodiment of a reduced conductivity antenna according to an aspect of the present invention;

[0016] Figure 5 is a front elevation view of an exemplary embodiment of a reduced conductivity RFID device according to an aspect of the present invention; and

[0017] Figure 6 is a top plan view of another exemplary embodiment of a reduced conductivity RFID device according to an aspect of the present invention. DETAILED DESCRIPTION

[0018] As required, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention, and the present invention can be implemented in various forms. Therefore, the specific details disclosed herein should not be interpreted as limiting, but only as the basis for the scope of the invention and as a representative basis for teaching those skilled in the art to use the present invention in different ways in almost any appropriate manner.

[0019] The inventory area 10 of an EAS system typically includes a variety of items tagged with a variety of RFID devices, each of which is configured in a different manner. Due to the differently configured items (which have different effects on the performance of the associated RFID devices) and the different configurations of the RFID devices themselves, some RFID devices within the EAS system will have a particularly large sensitivity at the operating frequency of the RFID reader of the EAS system. This high sensitivity causes such RFID devices to have a large read range, which can increase the chance that such RFID devices will be read by an RFID reader in a read zone where the RFID device is not present (i.e., a false alarm). Therefore, according to one aspect of the present invention, the configuration of the RFID device can be modified from a conventional design to reduce its read range.

[0020] There are several factors that can affect the performance characteristics of an RFID device, such that various modifications can be made to the RFID device (alone or in combination) to change its performance and read range. In the most basic case, an RFID device includes an RFID chip coupled to an antenna, where the RFID chip contains various information (e.g., a unique identifier) ​​and the antenna is configured to receive signals or energy from an RFID reader and return signals to the RFID reader. The size and material composition of the antenna will affect its conductivity, which affects the read range and performance of the associated RFID device. In general, larger antennas (i.e., antennas with a relatively large footprint and / or thickness) will tend to have greater conductivity, and therefore read range, than smaller antennas formed from the same material. Similarly, at a given antenna size, an antenna formed from a material with a relatively large conductivity will have a greater read range than an antenna formed from a material with a smaller conductivity.

[0021] Figure 2A and Figure 2B shows how changes in the conductivity of the antenna can affect its read range for different product types. Figure 2B In the dashed line (at 40 in FIG. 2A and Figure 2B 2A at 40') represents an RFID device attached to a denim product, while the solid line (in FIG. 2A at 50 and Figure 2B2A ) represents an RFID device attached to card stock, which has dielectric properties that are very different from denim. The operating frequency of the RFID reader of the EAS system is represented by line 60. The antenna of the RFID device in FIG. 2A is provided according to conventional design and thus has a relatively high conductivity. This may include the antenna of such RFID device being constructed of a highly conductive material (e.g., aluminum foil) and / or a material that is provided at a thickness of approximately 10 um (micrometers). In contrast, Figure 2B A modified antenna of an RFID device (which may have the same footprint as the antenna represented in FIG. 2A ) is provided in accordance with the present invention and has lower conductivity, which may be achieved by employing an antenna material having a relatively lower conductivity (e.g., conductive ink, which has a lower conductivity compared to aluminum foil) and / or a material set in a smaller thickness (e.g., a thickness in the range of approximately 0.1 um to 10 um).

[0022] As can be seen by comparing Figure 2A and Figure 2B As can be seen, the antenna with higher RF conductivity of FIG. 2A has a higher Figure 2B The antenna of the present invention has a greater peak sensitivity and has a greater sensitivity and a higher read range at the operating frequency 60. By reducing the read range at the operating frequency, the antenna according to the present invention is less likely to generate a false alarm. In addition, the shorter read range of the antenna according to the present invention allows the size of the transition zone 30 of the EAS system to be reduced, which can allow for a larger inventory zone 10.

[0023] Additionally, it will be seen that the conventional antenna of FIG. 2A has a relatively narrow bandwidth in which the sensitivity (and read range) of the antenna drops off sharply from the peak sensitivity. As a result of this narrow bandwidth, it is more likely that there will be relatively large differences between the sensitivity and read range of the two antennas associated with different items at different frequencies. For example, this sensitivity and read range difference at operating frequency 60 is represented at "A" in FIG. 2A. The lower conductivity antenna according to the present invention has a larger bandwidth in which the sensitivity and read range of the antenna decreases gradually away from the peak sensitivity. By increasing the bandwidth (and reducing the variability of sensitivity and read range), it is more likely that the sensitivity and read range of the antennas associated with different items will be similar at different frequencies (including at operating frequency 60), such as Figure 2B By making the performance of the antenna more stable (including reducing the sensitivity range at the operating frequency 60), there is greater flexibility in the placement of items in the inventory area 10 because there is less need to specifically position certain items farther from the detection zone 20 to avoid false alarms. For example, denim tagged with an RFID device having a thicker antenna than a cotton shirt can be placed farther away in the first read zone based at least in part on the properties of the denim.

[0024] Figure 2B Antennas with reduced RF conductivity compared to antennas of conventional RFID devices are demonstrated, resulting in reduced peak sensitivity and increased bandwidth. Figure 2B The antenna represented in may be considered to have a "medium" or "intermediate" conductivity, which may be further reduced by employing aspects of the present invention. Figure 3 2A, and a dashed line 80 represents an RFID device with a "medium" antenna conductivity. Figure 2B ), and dotted line 90 represents an RFID device with low antenna conductivity. Figure 3 As shown, reducing antenna RF conductivity can be associated with both reduced read range and increased bandwidth, with an antenna having sufficiently "low" conductivity producing a substantially uniform read range over a very wide frequency range.

[0025] In some embodiments, configuring the antenna with a relatively lower RF conductivity results in a reduction in peak sensitivity greater than or equal to 1 dB, 1.5 dB, 2.0 db, 2.5 db, 3.0 db, 3.5 db, 4.0 db, 4.5 db, 5.0 db, or more.

[0026] In another embodiment, configuring the antenna with a relatively lower RF conductivity results in an increase in bandwidth greater than or equal to 5%, 6%, 7%, 8%, 9%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15% or more.

[0027] In yet another embodiment, configuring the antenna with a relatively lower RF conductivity results in a reduction in peak sensitivity as described above and an associated increase in bandwidth as described above.

[0028] Thus, it should be appreciated that techniques according to the present invention may be employed to stabilize the performance of an RFID device of an EAS system. For example, techniques according to the present invention may be employed to make the read ranges of two RFID devices the same or at least substantially the same at the operating frequency of the EAS system, even if the two RFID devices have antennas configured in very different ways (e.g., one having a much larger aspect ratio than the other) and are associated with very different items. The specific techniques employed and the specific configuration of the antennas of the RFID devices according to the present invention may depend on a variety of factors. These factors include (but are not limited to) the operating frequency of the RFID reader of the EAS system, the critical read range, the item to which the RFID device is to be associated, the manner in which the RFID device is to be paired with its associated item, the location of the RFID device on the associated item, any desired structural features of the RFID device (e.g., the material composition and / or dimensions of the antenna), and combinations thereof. Different antenna configurations may be tested (e.g., by electromagnetic simulation) to determine whether a particular configuration produces desired performance characteristics.

[0029] As described above, using conductive ink and / or reducing the thickness of the antenna are possible methods for reducing the conductivity of the antenna. When using conductive ink, the conductivity of an antenna of a particular size can be changed by adjusting the amount of conductive material in the ink (e.g., by adjusting the ratio of conductive material to non-conductive material in the ink). Figure 3 The relationship demonstrated is that as the ratio of conductive material to non-conductive material decreases (ie, as less conductive material is included in the conductive ink), the conductivity of the antenna will decrease.

[0030] In one embodiment, the relative conductivity of the conductive ink is more than 5%, 6%, 7%, 8%, 9%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5% or 15% lower than the conductivity of the foil material used for the antenna.

[0031] In another embodiment, for equal thickness of foil material, the relative conductivity of the conductive ink is more than 5%, 6%, 7%, 8%, 9%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5% or 15% lower than the conductivity of the foil material.

[0032] Regarding the thickness of the antenna, for a given material type (e.g., aluminum foil or conductive ink), the thickness of the antenna can be reduced to achieve the desired conductivity and device performance. In one embodiment, the thickness of the antenna is in the range of 0.1um to 10um to reduce the peak sensitivity of the RFID device by 3dB and correspondingly increase the bandwidth of the RFID device by 10%. At the operating frequency, the thickness of the antenna can also be equal to or less than one skin depth of the material forming the antenna.

[0033] It should be understood that changing the material composition and / or thickness of an antenna is not the only way to change its conductivity. For example, material may be omitted or removed from the interior of the antenna, such as Figure 4 As shown. Figure 4 In the embodiment of the present invention, the antenna 100 is provided with a plurality of openings or holes 110 defined within its perimeter 120. As compared to an antenna formed of the same material and having the same size and perimeter, the holes 110 effectively introduce resistance into the antenna 100, thereby Figure 4 The antenna 100 will have a lower conductivity. It should be understood that the holes 110 can be formed according to any suitable method (e.g., by printing conductive ink in a specific pattern, or by forming a conventional antenna and then removing material in selected locations to define the holes), and any number, size, location and configuration can be used without departing from the scope of the present invention. Generally, as the size and / or number of holes increase, the conductivity of the antenna and the read range of the RFID device decreases.

[0034] Figure 5 Another possible approach for controlling the bandwidth and performance of RFID devices is presented. Figure 5 In the RFID device 130 of the present invention, the RFID chip 140 and the antenna 150 are associated with one side of a non-conductive substrate 160 (e.g., formed of paper or plastic material). A control layer 170 is associated with the opposite side of the substrate 160, wherein the control layer 170 is formed of a conductive ink or a thin vapor deposited metal or other radio frequency absorbing material. The control layer 170 can be applied by any known means in the art, including but not limited to lamination to the back of the substrate 160 and / or printing by a thermal printer or inkjet printer. The control layer 170 can extend across the entirety of the associated surface of the substrate 160 or cover only a portion thereof.

[0035] According to one aspect of the invention, control layer 170 will absorb some of the RF energy that antenna 150 would otherwise receive, thereby effectively reducing the read range of antenna 150. Similar to antennas, the configuration of control layer 170 (including its size, thickness, and material composition) can be varied to adjust its conductivity, wherein an increase in the conductivity of control layer 170 effectively reduces the conductivity of the associated antenna 150 (e.g., according to Figure 3The use of control layer 170 can be advantageous if the read range and bandwidth of the antenna are to be modified, but there are limits to the extent to which the antenna itself can be modified.

[0036] Figure 6 Another exemplary RFID device 180 is shown in which a secondary structure can be employed to modify the performance of an associated antenna. Figure 6 In the embodiment of the present invention, the RFID device 180 includes an RFID chip 190 and an antenna 200. Figure 5 However, the RFID chip 190 is not physically connected to the antenna 200 (e.g., using a pad according to conventional design) (e.g., Figure 5 200 ), but rather the RFID chip 190 is connected to the conductive loop 210 to define a reactive strip 220 that is physically separated from the antenna 200 (but still coupled to the antenna). According to one aspect of the present invention, similar to Figure 5 If the control layer 170 is not provided, the conductive loop 210 will absorb some of the RF energy that the antenna 200 would otherwise receive, thereby effectively reducing the read range of the antenna 200. As described above with respect to the antenna or control layer, the configuration of the conductive loop 210 (including its size, thickness, and material composition) can be varied to adjust its conductivity, wherein an increase in the conductivity of the conductive loop 210 effectively reduces the conductivity of the associated antenna 200 (e.g., according to Figure 3 200 ), thereby reducing the sensitivity of the associated antenna 200. In some embodiments, the conductive loop 210 is made of a conductive material different from the conductive material used for the antenna 200. For example, if the antenna 200 is made of copper, the conductive loop can be made of aluminum. In another embodiment, the conductive loop is formed of a conductive ink that has a lower conductivity than the conductive foil material used for the antenna. Therefore, the conductive loop 210 can be configured to have a greater resistance than the antenna.

[0037] It should be understood that the above embodiments illustrate some applications of the principles of the subject matter of the present invention. A large number of modifications may be made by those skilled in the art without departing from the spirit and scope of the subject matter claimed, including those feature combinations disclosed or claimed separately herein. For these reasons, the scope of the present invention is not limited to the above description, but is as set forth in the following invention claims, and it should be understood that the invention claims may be directed to its features, including the feature combinations disclosed or claimed separately herein.

Claims

1. A method of manufacturing a radio frequency identification device for use in an radio frequency identification enabled electronic article surveillance system, the method comprising: Provide RFID chips; Provide antennas; as well as coupling the RFID chip to the antenna, wherein the antenna is configured with a relatively low RF conductivity to reduce a peak sensitivity of the RFID device and increase an associated bandwidth of the RFID device; wherein the RFID chip is connected to a conductive loop to define a reactive strip physically separated from the antenna; wherein the conductive loop is configured to have a greater resistance than the antenna; The conductive loop is formed of a material different from that of the antenna.

2. The method according to claim 1, wherein: Configuring the antenna to have a relatively low RF conductivity results in a reduction in the peak sensitivity of greater than or equal to 1 dB.

3. The method according to claim 1, wherein: Configuring the antenna with a relatively low RF conductivity results in an increase in the bandwidth of more than 10%.

4. The method according to claim 1, wherein: Configuring the antenna with a relatively low radio frequency conductivity results in a reduction in the peak sensitivity of greater than 1 dB and an associated increase in the bandwidth of greater than 10%.

5. The method according to any one of claims 1 to 4, wherein: Providing the antenna includes forming the antenna with a low conductivity material, the low conductivity material including a conductive ink having a lower conductivity than a conductive foil material.

6. The method according to claim 5, wherein: The conductivity of the conductive ink is more than 10% lower than the conductivity of the foil material.

7. The method according to claim 6, wherein: When the foil material and the conductive ink have equal thickness, the conductivity of the conductive ink is more than 10% lower than the conductivity of the foil material.

8. The method according to claim 1, wherein: The providing of the antenna includes: providing the antenna with a relatively small thickness to reduce the peak sensitivity of the RFID device and increase the bandwidth of the RFID device.

9. The method according to claim 8, wherein: The thickness of the antenna is in the range of 0.1 um to 10 um to reduce the peak sensitivity of the RFID device by 3 dB and correspondingly increase the bandwidth of the RFID device by 10%.

10. The method according to claim 8, wherein: The thickness of the antenna is equal to or lower than a skin depth of a material forming the antenna.

11. The method according to claim 1, wherein: Providing the antenna includes forming the antenna using a combination of conductive material and non-conductive material.

12. The method according to claim 1, wherein: Providing the antenna includes forming one or more holes in the antenna.

13. The method according to any one of claims 1 to 12, further comprising: A control layer separate from the RFID chip and the antenna is incorporated into the RFID device, wherein the control layer is at least partially formed of a material configured to absorb radio frequency energy.

14. The method according to claim 1, wherein: The conductive loop is formed from a conductive ink having a lower conductivity than a conductive foil material used for the antenna.

15. The method according to claim 14, wherein: The conductivity of the conductive ink is more than 10% lower than the conductivity of the foil material.

16. The method according to claim 15, wherein: When the foil material and the conductive ink have equal thickness, the conductivity of the conductive ink is more than 10% lower than the conductivity of the foil material.

17. A method of maximizing the performance of a radio frequency identification enabled electronic article surveillance system, the method comprising: tagging a first article to be monitored by the electronic article surveillance system with a first RFID device having a first antenna coupled to a first RFID chip; as well as a second article to be monitored by the electronic article surveillance system is tagged with a second RFID device having a second antenna coupled to a second RFID chip, wherein: The first item and the second item are configured to affect the performance of an associated RFID device in different ways, and the first antenna and the second antenna being configured differently based at least in part on properties of the first article and the second article to have similar read ranges at a predetermined frequency within a first read zone and a second read zone of the electronic article surveillance system; The second antenna has a larger size than the first antenna, and the second antenna is formed of a second material having lower conductivity than the first material forming the first antenna.

18. A radio frequency identification enabled electronic article surveillance system comprising: at least one radio frequency identification device, the at least one radio frequency identification device comprising an antenna and a radio frequency identification chip coupled to the antenna; a first reading area; a second reading area; as well as a transition zone, the transition zone being positioned between the first reading zone and the second reading zone, wherein the antenna of the at least one RFID device is configured to have a reduced RF conductivity to reduce a peak sensitivity of the at least one RFID device and to increase a bandwidth of the at least one RFID device, thereby allowing the at least one RFID device to be read only in the first read zone when present in the first read zone and to be read only in the second read zone when present in the second read zone; wherein the at least one RFID device comprises an RFID chip connected to a conductive loop to define a reactive strip physically separated from the antenna; wherein the conductive loop is configured to have a greater resistance than the antenna; The conductive loop is formed of a material different from that of the antenna.

19. The RFID-enabled electronic article surveillance system of claim 18, wherein: Configuring the antenna to have a relatively low RF conductivity results in a reduction in the peak sensitivity of greater than or equal to 1 dB.

20. The RFID-enabled electronic article surveillance system of claim 18, wherein: Configuring the antenna with a relatively low RF conductivity results in an increase in the bandwidth of more than 10%.

21. The RFID-enabled electronic article surveillance system of claim 18, wherein: Configuring the antenna with a relatively low radio frequency conductivity results in a reduction in the peak sensitivity of greater than 1 dB and an associated increase in the bandwidth of greater than 10%.

22. The RFID-enabled electronic article surveillance system of any one of claims 18 to 21, wherein: The antenna is formed from a conductive ink having a lower conductivity than a conductive foil material.

23. The RFID-enabled electronic article surveillance system of claim 22, wherein: The conductivity of the conductive ink is more than 10% lower than the conductivity of the foil material.

24. The RFID enabled electronic article surveillance system of claim 23, wherein the conductivity of the conductive ink is more than 10% lower than the conductivity of the foil material when the foil material and the conductive ink are of equal thickness.

25. The RFID-enabled electronic article surveillance system of claim 18, wherein: Providing the antenna includes providing the antenna with a relatively small thickness to reduce the peak sensitivity of the RFID device and increase the bandwidth of the RFID device.

26. The RFID-enabled electronic article surveillance system of claim 25, wherein: The thickness of the antenna is in the range of 0.1 um to 10 um to reduce the peak sensitivity of the RFID device by 3 dB and correspondingly increase the bandwidth of the at least one RFID device by 10%.

27. The RFID-enabled electronic article surveillance system of claim 25, wherein: The thickness of the antenna is equal to or lower than a skin depth of a material forming the antenna.

28. The RFID enabled electronic article surveillance system of any one of claims 18 to 27, wherein: The antenna is formed of a combination of conductive and non-conductive materials.

29. The RFID-enabled electronic article surveillance system of claim 18, wherein: At least one aperture is defined in the antenna.

30. The RFID enabled electronic article surveillance system of any one of claims 18 to 29, wherein: The at least one RFID device includes a control layer spaced apart from the RFID chip and the antenna, and the control layer is at least partially formed of a material configured to absorb RF energy.

31. The RFID-enabled electronic article surveillance system of claim 18, wherein: The conductive loop is formed from a conductive ink having a lower conductivity than the conductive foil material.

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