Antenna and radio frequency identification (RFID) label with inductive loop

Abstract

An antenna and a radio frequency identification (RFID) label is described. The antenna includes one or more loops. Each loop has one or more crossing points where portions of the antenna are in contact with each other. The antenna has an insulated coating to prevent physical contact of conductive material of the antenna at the crossing point. The RFID label includes an RFID transponder and the antenna coupled to the RFID transponder. The RFID transponder includes an integrated circuit and an inductive loop electronically coupled to the integrated circuit. The inductive loop has at least one meander-shaped portion.

Description

ANTENNA AND RADIO FREQUENCY IDENTIFICATION (RFID) LABEL WITH INDUCTIVE LOOPCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 606890 entitled “Radio Frequency Identification (RFID) Label with Meandered Inductive Loop” filed December 6, 2023, and U.S. Provisional Application No. 63 / 722,745 entitled “Antenna and Radio Frequency Identification (RFID) Label” filed November 20, 2024, both of which are expressly incorporated by reference herein in their entirety.BACKGROUND

[0002] The present disclosure relates generally to radio frequency identification (RFID) tags or labels. More particularly to a RFID labels with an inductive loop and / or an antenna.

[0003] In recent years, RFID technology has gained significant traction across various industries, revolutionizing inventory management, supply chain logistics, asset tracking, etc. Currently, application of RFID labels in textiles (for example, clothing items) is rapidly increasing.SUMMARY

[0004] The following presents a simplified summary of one or more implementations of the present disclosure in order to provide a basic understanding of such implementations. This summary is not an extensive overview of all contemplated implementations and is intended to neither identify key or critical elements of all implementations nor delineate the scope of any or all implementations. Its sole purpose is to present some concepts of one or more implementations of the present disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0005] One implementation of the present disclosure relates to a radio frequency identification (RFID) label. The RFID label includes an RFID transponder and an antenna coupled to the RFID transponder. The RFID transponder includes an integrated circuit and an inductive loopelectronically coupled to the integrated circuit. The inductive loop has at least one meander- shaped portion.

[0006] In some implementations, the inductive loop matches an impedance of the integrated circuit.

[0007] In some implementations, the integrated circuit has capacitive impedance, and the inductive loop matches the capacitive impedance.

[0008] In some implementations, the inductive loop includes a first arm segment and a second arm segment. At least one of the first arm segment and the second arm segment includes the at least one meander-shaped portion.

[0009] In some implementations, the at least one meander-shaped portion includes one or more turns.

[0010] In some implementations, a trace length of the inductive loop, a count of turns, a height of each turn, a bend angle of each turn, a depth of each turn, and a radius of curvature of each turn are set to match an impedance of the integrated circuit.

[0011] In some implementations, a trace width of the inductive loop is set to make the RFID label withstand one or more wash cycles.

[0012] In some implementations, the inductive loop is formed from a combination of a plurality of conductive materials.

[0013] In some implementations, the RFID label further includes a backing layer such that the RFID transponder and the antenna are provided on the backing layer.

[0014] Another implementation of the present disclosure relates to a radio frequency identification (RFID) transponder. The RFID transponder includes an integrated circuit and an inductive loop electronically coupled to the integrated circuit to match an impedance of integrated circuit. The inductive loop has at least one meander-shaped portion.

[0015] In some implementations, the RFID transponder further includes an encapsulation member to encapsulate the integrated circuit and the inductive loop.

[0016] Another implementation of the present disclosure relates to an antenna. The antenna includes one or more loops. Each loop has one or more crossing points where portions of the antenna are in contact with each other. The antenna has an insulated coating to prevent physical contact of conductive material of the antenna at the crossing point.

[0017] In some implementations, the portions of the antenna in contact with each other at the crossing point correspond to same loop.

[0018] In some implementations, the portions of the antenna in contact with each other at the crossing point correspond to different loops.

[0019] In some implementations, the antenna is a dipole antenna having a first section and a second section.

[0020] In some implementations, the first section and the second section are connected via at least one curve segment.

[0021] In some implementations, the first section and the second section are connected via at least one straight segment.

[0022] In some implementations, the loops are helical or spiral.

[0023] Another implementation of the present disclosure relates to a radio frequency identification (RFID) label. The RFID label includes an integrated circuit and an antenna including one or more loops. Each loop has one or more crossing points where portions of the antenna are in contact with each other. The antenna has an insulated coating to prevent physical contact of conductive material of the antenna at the crossing point.

[0024] In some implementations, the portions of the antenna in contact with each other at the crossing point correspond to same loop.

[0025] In some implementations, the portions of the antenna in contact with each other at the crossing point correspond to different loops.

[0026] In some implementations, the RFID label includes an inductive loop to couple the antenna to the integrated circuit.

[0027] In some implementations, the inductive loop has at least one meander-shaped portion.

[0028] Additional advantages and novel features relating to implementations of the present disclosure will be set forth in part in the description that follows, and in part will become more apparent to those skilled in the art upon examination of the following or upon learning by practice thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various objects, aspects, features, and advantages of the disclosure will become more apparent and better understood by referring to the detailed description taken in conjunction with the accompanying drawings, in which like reference characters identify corresponding elements throughout. The drawing figures are not necessarily drawn to scale, and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness.

[0030] FIG. 1 is a diagram of a radio frequency identification (RFID) label, in accordance with some implementations of the present disclosure.

[0031] FIGS. 2A and 2B are diagrams of RFID transponders that can be used in the RFID label of FIG. 1, in accordance with some implementations of the present disclosure.

[0032] FIG. 3 is a diagram that illustrates a fabric item with the RFID label of FIG. 1, in accordance with some implementations of the present disclosure.

[0033] FIGs. 4-7 illustrate schematic views of an antenna, according to some implementations of the present disclosure.

[0034] FIGs. 8-12 illustrate schematic views of an RFID label, according to some implementations of the present disclosure.

[0035] FIG. 13 is an example of inventory management or security system according to some implementations of the present disclosure.

[0036] FIG. 14 is an example of an integrated circuit or microcontroller according to some implementations of the current disclosure.DETAILED DESCRIPTIONTerminology

[0037] Reference throughout this specification to one aspect, an aspect, one example or an example means that a particular feature, structure or characteristic described in connection with the disclosure, or examples may be a feature included in at least example of the present disclosure . Thus, appearances of the phrases in one aspect, in an aspect, one example or an example in various places throughout this specification are not necessarily all referring to the same example. Furthermore, the particular features, structures or characteristics may be combined in any suitable combinations and / or sub combinations in one or more implementations or examples.

[0038] The term exemplary used in this disclosure means serving as an example, instance, or illustration, and should not necessarily be construed as preferred or advantageous over other examples presented in this disclosure.

[0039] Throughout the disclosure, the terms substantially or approximately may be used as a modifier for a geometric relationship between elements or for the shape of an element or component. While the terms substantially or approximately are not limited to a specific variation and may cover any variation that is understood by one of ordinary skill in the art to be an acceptable level of variation, some examples are provided as follows. In one example, the term substantially or approximately may include a variation of less than 10% of the dimension of the object or component. In another example, the term substantially or approximately may include a variationof less than 5% of the object or component. If the term substantially or approximately is used to define the angular relationship of one element to another element, one non-limiting example of the term substantially or approximately may include a variation of 5 degrees or less. These examples are not intended to be limiting and may be increased or decreased based on the understanding of acceptable limits to one of skill in the relevant art.

[0040] For purposes of the disclosure, directional terms are expressed generally with relation to a standard frame of reference when the aspects or articles described herein are in an in-use orientation. In some examples, the directional terms are expressed generally with relation to a lefthand coordinate system.

[0041] Terms such as a, an, and the, are not intended to refer to only a singular entity, but also include the general class of which a specific example may be used for illustration. The terms a, an, and the, may be used interchangeably with the term at least one. The phrases at least one of and comprises at least one of followed by a list refers to any one of the items in the list and any combination of two or more items in the list. All numerical ranges are inclusive of their endpoints and non-integer values between the endpoints unless otherwise stated.

[0042] The terms first, second, third, and fourth, among other numeric values, may be used in this disclosure. It will be understood that, unless otherwise noted, those terms are used in their relative sense only. In particular, certain components may be present in interchangeable and / or identical multiples (e.g., pairs). For these components, the designation of first, second, third, and / or fourth may be applied to the components merely as a matter of convenience in the description.Overview

[0043] The following presents a simplified overview of one or more aspects in order to provide a basic understanding of such aspects. This overview is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. The sole of purpose of this overview is to present someconcepts of one or more aspects in a simplified form as a prelude to the mode detailed description that is presented later.

[0044] Present disclosure discloses washable RFID label that can withstand the rigors of washing and laundering activities. The RFID label includes an RFID transponder and an antenna coupled to the RFID transponder. The RFID transponder includes an RFID chip (e.g., an integrated circuit) electronically coupled to an inductive loop for impedance matching. The inductive loop incorporates a meander shape design to provide a thick trace path that can withstand industrial washing without getting damaged (i.e. has improved strength and damage resistance). In other words, the washable RFID label exhibits durability and resilience against repeated wash cycles, without compromising its functionality.

[0045] The present disclosure further discloses an antenna having one or more loops. Each loop may have one or more crossing points, where portion of the antenna contact each other. The antenna has insulation coating to prevent physical contact of conductive material of the antenna at the crossing point(s). Due to loops, the antenna has larger overall length or effective length, however, the antenna has smaller footprint, which may improve the size and other properties (e.g., improved flexibility and ability to integrate into fabric or other flexible or low profile RFID tags).

[0046] Before turning to the Figures, it should be understood that the disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.

[0047] FIG. 1 is a diagram of an RFID label 100, in accordance with some implementations of the present disclosure. The RFID label 100 may include an RFID transponder 102A and an antenna 104. The RFID transponder 102A and the antenna 104 may be provided on (e.g., attached to) a backing layer 106. In some implementations, there may be an adhesive layer provided between the backing layer 106, the RFID transponder 102A, and the antenna 104 to affix the RFID transponder 102A and the antenna 104 on the backing layer 106. The RFID label 100 can be an active RFID label or a passive RFID label, without deviating from the scope of the disclosure.

[0048] The backing layer 106 may be a fabric material including a natural fiber and / or a synthetic fiber. Examples of the fiber materials may include, but are not limited to, polyester, nylon, silk, cotton, wool, linen, hemp, rayon, acrylic, polyurethane (e.g., spandex, elastane), polymer fabric, or any other washable fabric material.

[0049] The antenna 104 may be coupled to the RFID transponder 102A. In some implementations, the antenna 104 may be designed as a mechanically shortened dipole. For example, the antenna 104 may be formed from an originally continuous electrical conductor which is separated at two locations 108, 110, thus forming a dipole. Suitably, the antenna 104 can be made from any of a variety of electrically conductive materials and / or components having a wide variety of lengths, sizes, shapes, patterns, etc. In some implementations, the antenna 104 may be provided with a meandering inductance. The terms “meander” or “meandering” herein refer to a back and forth pattern with curved bends / turns, e.g., a series of interconnected curves. In other implementations, the antenna 104 may have any other suitable shape or pattern without deviating from the scope of the disclosure. Further, the antenna 104 may be sufficiently durable to withstand repeated washing and / or other laundry processes without experiencing damage that may hinder operability of the RFID and / or performance degradation. For example, the diameter or trace width of the antenna may be increased to improve durability and / or flexibility of the antenna.

[0050] In some implementations, the RFID transponder 102A may be provided at the center 112 of the antenna 104 such that portions of the antenna 104 on either side of the RFID transponder 102 A are symmetric with respect to each other. For example, the RFID transponder 102A may be provided inside one of the turns of the antenna 104 that is at the center 112. In some other aspects of the disclosure, the RFID transponder 102A can be provided at any other suitable location of the antenna 104 without deviating from the scope of the disclosure.

[0051] The RFID transponder 102 A may include an integrated circuit 114A (for example, an electronic chip or an electronic chip module) and an inductive loop 116A electronically coupled to the integrated circuit 114A. In some implementations, the inductive loop 116A may be directly connected to the integrated circuit 114A. However, in some other implementations, the inductiveloop 116A may be coupled to the integrated circuit 114A via intermediate connection leads, for example, conductive leads or pads electrically coupled to contact pads of the integrated circuit 114 A to couple the integrated circuit 114A to the inductive loop 116A. The integrated circuit 114A may include selected electronics (e.g., a memory, a processor, etc., examples of which are provided below) and other suitable components for its functioning. In some implementations, the integrated circuit 114A may function to store and / or process information.

[0052] The inductive loop 116A may be a continuous electronic trace coupled to the integrated circuit 114A at its ends. The inductive loop 116A may be designed to match an impedance of the integrated circuit 114A. For example, when the integrated circuit 114A exhibits capacitive impedance, the inductive loop 116A is designed so as to match and compensate the capacitive impedance of the integrated circuit 114A.

[0053] The dimensions of the inducive loop (e.g., a trace width and length) may be adjusted to match and compensate impedance of the integrated circuit 114A (e.g., to create enough inductance when subject to a field to complex-conjugate impedance match the electronic chip or electronic chip module 114A). Impedance matching may be implemented to maximize the power transfer and minimize reflections from the load. The term “impedance matching” as noted above is not necessarily limited to complex conjugate impedances and may be used more generally to mean “choosing impedances that work well together.” For example, interpretation may encompass impedance bridging, where the load impedance may be much larger than the source impedance. Bridging connections may be used to maximize the voltage transfer, rather than the power transfer. The concepts described herein are further intended to encompass other impedance selection schemes that may be applied when energy is transferred between a source and a load.

[0054] The inductive loop 116A may be inductively coupled to the antenna 104, thereby, communicatively coupling the integrated circuit 114A to the antenna 104. When operating in receiving mode, the antenna 104 receives an incoming signal from an external device (for example, and RFID reader) and provides the signal to the inductive loop 116A. The inductive loop 116A then provides the received signal to the integrated circuit 114A for processing. When operating intransmitting mode, the integrated circuit 114A generates and provides a transmission signal to the inductive loop 116A, which then provides the transmission signal to the antenna 104 for further transmission (e.g., broadcast) to an external device.

[0055] In some implementations, the RFID label 100 may be attached to a washable fabric material. Thus, when the fabric material undergoes washing, the RFID label 100 may be washed along with it. In contrast to certain conventional RFID labels in which inductive loop may be damaged upon washing and / or other agitation and compromises the functionality of the RFID label, the inductive loop 116A of the RFID label 100 has increased width of the inductive loop and or increased dimensions while remaining flexible so that the RFID label 100 can withstand one or more washing cycles without compromising its functionality.

[0056] In some aspects of the disclosure, the inductive loop 116A may include at least one meander-shaped portion. For example, as shown in FIG. 1, the inductive loop 116A includes a first arm segment 118A and a second arm segment 118B opposite to the first arm segment 118A. A first meander-shaped portion 120 is provided on the first arm segment 118A and a second meandershaped portion 122 is provided on the second arm segment 118B. The first meander-shaped portion 120 and the second meander-shaped portion 122 may be symmetrical to each other. While in FIG. 1 both first and second arm segments 118 A, 118B are shown to include a meander-shaped portion, the scope of the disclosure is not limited to it. In some other implementations, a meander-shaped portion may only be provided in the first arm segment 118A or the second arm segment 118B. In some other aspects, a meander-shaped portion provided in the first arm segment 118A may not be symmetric with a meander-shaped portion provided in the second arm segment 118B. In some other implementations, the first arm segment 118A and / or the second arm segment 118B may include more than one meander-shaped portions without deviating from the scope of the disclosure. Each meander-shaped portion 120, 122 may include one or more turns, e.g., curved bends. Though in FIG. 1 all turns in the meander-shaped portions 120, 122 are shown to be of the same size and dimensions, the scope of the disclosure is not limited to it. In some other implementations, different turns in the meander-shaped portions 120, 122 can have different geometric characteristics as per requirement.

[0057] Inclusion of one or more meander-shaped portions (e.g., the first and second meandershaped portions 120, 122) in the inductive loop 116A allows a trace width 124 or width of the inductive loop 116A to be set in a range that makes the RFID label 100 withstand one or more wash cycles (e.g., when an article to which the RFID label 100 is attached is washed). In other words, meandering shape in the inductive loop 116A allows the use of a thick trace path which does not crack or get damaged during washing activities, thus making the RFID label 100 survive industrial washing without compromising its functionality. In one example, the trace width 124 of the inductive loop 116A may be greater than 0.6 millimeters (mm). In another example, the trace width 124 of the inductive loop 116A may be set in the range of 0.6 mm to 2 mm. In another example, the trace width 124 of the inductive loop 116A may be greater than 2mm. Additionally, by including one or more meander-shaped portions (e.g., the first and second meander-shaped portions 120, 122) in the inductive loop 116A, length of the trace can be increased without increasing a vertical length 126 of the inductive loop 116A. In some aspects of the disclosure, the trace width 124 in the one or more meander- shaped portions (e.g., the first and second meandershaped portions 120, 122) may be different from trace width in non-meandered portions of the inductive loop 116A. However, in other aspects, the trace width 124 in the one or more meandershaped portions (e.g., the first and second meander-shaped portions 120, 122) may be same as the trace width in the non-meandered portions of the inductive loop 116A.

[0058] Further, various parameters of one or more meander-shaped portions (e.g., the first and second meander-shaped portions 120, 122) in the inductive loop 116A may be set to efficiently match the impedance of the integrated circuit 114A. Examples of the parameters may include a count of turns, a radius of curvature of each turn (turn radius), a height of each turn, distance in consecutive turns, a bend angle of each turn, a depth of each turn, trace length of the inductive loop 116A, or the like. Height of each turn may be defined as a separation between starting and ending points of one turn. Distance in consecutive turns may be defined as a separation between a starting point of one turn and a starting point of the next turn. Depth 128 of a turn may be defined as a distance from top to bottom of the turn. Trace length may be defined as overall length covered by electronic trace of the inductive loop 116A. These parameters collectively define geometriccharacteristics of the inductive loop 116A, influencing its performance in terms of frequency response, impedance matching, radiation pattern, etc., thus allowing maximum power transfer to the integrated circuit 114A during read- write process. As a result, the inductive loop 116A efficiently compensates for the impedance of the integrated circuit 114A, while enduring a washing process or other mechanical agitation.

[0059] In some implementations, the inductive loop 116A is formed from a combination of a plurality of conductive materials, for example, aluminum, aluminum alloys, copper, copper alloys, or the like. In some other implementations, the inductive loop 116A can be formed from a single conductive material without deviating from the scope of the disclosure.

[0060] Additionally, or alternatively, the RFID transponder 102A may include an encapsulation member 130 that encapsulates the integrated circuit 114A and the inductive loop 116A. The encapsulation member 130 may further enhance the protection of the RFID transponder 102 A from washing and / or other laundry processes.

[0061] In some aspects of the disclosure, the RFID transponder 102A and the antenna 104 may be provided on a non-folded portion (defined by axes 132A and 132B) of the backing layer 106. In some other implementations, some portion of the antenna 104 can also be provided on folded portions of the backing layer 106. Folded portions of the backing layer 106 are defined as an area between axes 134A and 132A and another area between axes 134B and 132B. The axis 134A and 134B demarcate a cutting axis along which the backing layer 106 is cut to obtain an individual RFID label 100 from a reel. For example, an array of RFID labels 100 may be provided to customers in a fan-fold or a roll arrangement by folding or rolling the array appropriately and each RFID label 100 is defined between corresponding axes 134A and 134B.

[0062] In some other aspects of the disclosure, the RFID transponder 102A may be replaced by an ultra-high frequency identification UHFID transponder or any other suitable wireless transponder including the meandered inductive loop 116A, without deviating from the scope of the disclosure.

[0063] The RFID label 100 can be used in various applications such as inventory management, supply chain logistics, asset tracking, security management, etc. More particularly, the RFID label 100 can be attached to any fabric item for inventory management, supply chain logistics, asset tracking, security management, etc. In some aspects of the disclosure, the RFID transponder 102A can wirelessly communicate with an RFID reader. The RFID reader can retrieve information stored in the RFID transponder 102A and further provide the obtained information to a computer database. The obtained information can further be verified / analyzed based on the computer database. Thus, the RFID label 100 can be applied for (i) inventory management and loss prevention with ease of e-commerce deliveries and (ii) self-checkout and mobile checkout. Some examples of inventory management and loss prevention are described in additional detail below with respect to FIG. 13.

[0064] In some aspects of the disclosure, the RFID label 100 can also provide a privacy mode and authentication functionality. For example, by retrieving the product information stored in the RFID transponder 102A, a customer can find out when and where the fabric item was produced and / or purchased. In the privacy mode, the RFID transponder 102A may only be read from a short distance (e.g., a few centimeters of tens of centimeters) by an RFID reader or may only be read by a person who knows a password.

[0065] Additionally, the RFID label 100 can be used in smart textiles and connected clothing applications. For example, the RFID label 100 can be attached to a washable smart t-shirt for communicating sensor signals (health parameters, workout analysis, etc.) generated by various sensors on the t-shirt to an RFID reader in a mobile device of a user.

[0066] FIGS. 2A and 2B are diagrams of RFID transponders 102B and 102C that can be used in the RFID label 100 of FIG. 1, in accordance with some implementations of the present disclosure. The RFID transponder 102B includes an integrated circuit 114B and a meandered inductive loop 116B, and the RFID transponder 102C includes an integrated circuit 114C and a meandered inductive loop 116C. In FIGS. 1, 2A, and 2B, common parts have been given like reference numerals, and a description thereof has been omitted unless there is a particular need. It isunderstood that description of common parts described in foregoing paragraphs applies to parts of FIGS. 2 A and 2B unless it is specifically described.

[0067] Referring now to FIGS. 2 A and 2B, the inductive loops 116B and 116C may be functionally similar to the inductive loop 116A but differ in geometric characteristics (e.g., the count of turns, the turn radius, the height of each turn, the distance in consecutive turns, the bend angle of each turn, the depth of each turn, the trace length, or the like). Different geometric characteristics may be incorporated in the inductive loops 116B and 116C to match impedances of different integrated circuits 114B and 114C, respectively. Further, as can be seen, the inductive loop 116A has lesser area inside the inductive loop 116A as compared to the inductive loops 116B and 116C, allowing the inductive loop 116A to have longer trace length than the inductive loops 116B and 116C.

[0068] Inductive loops 116A, 116B, 116C are shown for purpose and do not limit the scope of the disclosure. In other implementations, inductive loops can incorporate different geometric characteristics and different meander-shaped portions to meet impedance or other requirements.

[0069] FIG. 3 is a diagram that illustrates a fabric item 300 provisioned with RFID label 100, in accordance with some aspects of the present disclosure. The RFID label 100 may be sewn or otherwise affixed to the fabric item 300 using any suitable affixing means, e.g., an adhesive.

[0070] In some implementations, RFID transponder 102A, 102B, or 102C may be integrated into a product label, for example, a brand label serving as the backing layer 106. The brand label may be formed from a fabric material with a conductive wire (e.g., the antenna 104) stitched into or attached onto a backside or a frontside of the brand label. For example, the fabric material may include a natural fiber and / or a synthetic fiber, including fiber materials such as but not limited to polyester, nylon, silk, cotton, wool, linen, hemp, rayon, acrylic, and / or polyurethane (e.g., spandex, elastane). The RFID label 100 attached to the fabric item 300 is durable to withstand repeated washing and / or other laundry processes without experience significant damage and / or performance degradation. The RFID label 100 can be attached to the fabric item 300 in any suitable orientation and at any suitable location not limiting to the one shown in FIG. 3.

[0071] For simplicity and / or clarity herein FIG. 3 illustrates only one fabric item 300 provisioned with an RFID label 100. However, it is to be understood that in an actual implementation, an enterprise desiring to track, secure, and / or inventory its stock of fabric items (for example, an amusement park tracking costumes, a hotel tracking its bed linens, an organization tracking uniforms, etc.) may attach RFID labels 100 to the fabric items (such as the fabric item 300). Each RFID label 100 is suitably programmed or otherwise provisioned with a unique identifier that is communicated to an RFID reader when the RFID label 100 is queried, read, or otherwise. Accordingly, each fabric item 300 can be tracked and / or inventoried by the associated unique identifier obtained from the attached RFID label 100.

[0072] The present disclosure further discloses an antenna having one or more loops. Each loop may have one or more crossing points where portions of the antenna are in contact with each other. The antenna may be made of one or more conductive materials. Some examples of conductive materials include but are not limited to copper, copper alloys, steel, steel alloys, aluminum, aluminum alloys and the like. An insulation coating or layer may be provided on the conductive material to avoid physical contact of the conductive material at the crossing point(s). Some examples of insulating materials include but are not limited to nylon, polyurethane, fluorinated ethylene propylene, silicone, thermoplastic rubber, fiberglass, polyethylene, fluoropolymers, neoprene, polypropylene, styrene-butadiene, polyimides, polyester, polyvinylidene fluoride or polyvinylidene difluoride, ethylene-chlorotrifluoroethylene, polytetrafluoroethylene, rubbers, perfluoroalkoxy alkane, and / or polyvinyl chloride or the like. Due to the loop configuration, the antenna occupies less space and has higher effective length as compared to conventional antennas.

[0073] The loops create vectorial electrical currents, wherein horizontal components of the current participate in the radiation phenomenon and vertical components cancel each other out. Because of the loops, current in the antenna has a plurality of horizontal components to boost the radiation while keeping shorter footprint for the antenna.

[0074] Number of loops and size of the loops may vary as per the application requirement. For example, the effective length of the antenna refers to the length of the antenna that is activelycontributing to signal reception and transmission. In some examples, the effective length may be selected as equal to or around half the wavelength of the operating frequency of the RFID components and the number of loops may be selected based on packaging considerations. For example, when integrating the antenna into a clothing tag, the number of loops may be selected based on the width and / or length of the tag and the required effective length of the antenna. In one non-limiting example, the antenna may have an effective length of approximately 6.5 inches (in) or approximately half the wavelength of the 860-960MHz band used for UHF RFID systems. By creating self-crossing loops in the wire, the length of the antenna or area that includes the antenna may be decreased from an effective length of approximately 6.5 in to 0.5 - 2.5 inches, for example. The antenna can be used in any suitable application. In one example, the antenna is implemented in a RFID label. The antenna may be a dipole antenna having a first section and a second section. In one implementation, the first section and the second section may be coupled via one or more curve segments. In another example, the first section and the second section may be coupled via one or more straight segments. The antenna may include an excitation point, wherein the excitation point may be provided on the curved segment or the straight segment between the first section and the second section of the dipole antenna.

[0075] In some implementations, the antenna may be a monopole antenna. In one example, the monopole antenna may have one section and other section may be replaced with the ground.

[0076] The loops of the antenna may have any suitable shape. In one implementation the antenna may have helical loops extending along a backing layer onto which the antenna is provided. The loop may have an elliptical, a circular, or any other suitable profile. In other implementations, the loops may be spiral in nature. It is to be noted that the present disclosure is not limited to aforementioned shapes of the loop, and the loop can have any suitable shape, configuration, turns, and orientation in other implementations of the present disclosure.

[0077] In some implementations, the antenna may have one or more curved segments for connecting adjacent loops. For example, adjacent loops may be in contact via a curved segment. In some other implementations, the antenna may have one or more straight segments betweenadjacent loops. In some other implementations, the antenna may have straight and curved segments or any other suitable shaped segments between adjacent loops.

[0078] Referring to FIG. 4, an antenna 400 is shown, according to some implementations of the present disclosure. The antenna 400 may include one or more loops 410a-410f, wherein each loop 410a-410f may have one or more crossing points 420a-420f. Portions of the antenna 400 contact each other at the crossing point 420a-420f. As shown in FIG. 4, the portions of the antenna 400 contacting at the crossing point are part of the same loop. For example, in the loop 410a, a first portion 430 of the antenna 400 contacts with a second portion 440 of the antenna 400. In other words, the antenna 400 self-crosses at one point for each loop.

[0079] The antenna 400 may be made of conductive material. An insulation coating or insulation layer may be provided on the conductive material to prevent physical contact of the conductive material in the portions of the antenna 400 at the crossing points 420a-420f. The insulated coating or layer may be provided along overall length of the antenna 400.

[0080] In some implementations, the antenna 400 may be a dipole antenna having a first section 450 and a second section 460. An excitation point 480 may be provided on a straight segment 470 between the first section 450 and the second section 460. Number of the loops in the first section 450 and the second section 460 may be same. In some implementations, the antenna 400 may be a monopole antenna, wherein the first section 450 or the second section 460 may be replaced with the ground.

[0081] Referring to FIG. 5, the excitation points 480 may be provided on a curved segment 500 between the first section 450 and the second section 460.

[0082] Referring to FIG. 6, another implementation of the antenna 400 is shown. The antenna 400 shown in FIG. 6 may have one or more loops that are crossing adjacent loops. For example, the loop 410a and 410b may have one or more crossing points 510, 520 where portions of the antenna 400 contact each other, wherein these portions correspond to different loops 410a, 410b, which may be interchangeably referred to a first loop and second loop, respectively. In other words,the antenna 400 self-crosses at more than one point for each loop. The excitation point 480 may be provided on the straight segment 470 between the first section 450 and the second section 460.

[0083] As discussed in foregoing paragraphs, number of the loops of the antenna 400 may vary. Fig. 7 shows the antenna 400 having dense loops 530. Further, the excitation point 480 may be provided on the curved segment 500 between the first section and the second section.

[0084] The antenna 400 shown in FIGs. 4-7 has the loops having helical shape. The loops extend along a plane of a backing layer onto which the antenna 400 may be provided. Further, each loop of the antenna 400 may have an elliptical, circular, or any suitable profile in other implementations.

[0085] Referring to FIG. 8, an RFID label 600 is shown to include the antenna 400, an integrated circuit 610, and an inductive loop 620. The inductive loop 620 attached the integrated circuit 610 and the antenna 400 via coupling. The inducive loop 620 may share features with or may be analogous with any one or combination of the inductive loops 116A, 116B, and / or 116C described above. As shown in FIG. 8, the antenna 400 is electronically coupled to the inductive loop 620 along an edge 630 of the inductive loop 620. The antenna 400 may share features with or may be analogous with the antenna(s) 104 described above. The size, shape, separation, and number of wire loops along with the shape of the inductive loop may be optimized to achieve the best performance of the system which is the lowest value for power on tag forward (PoTF) at a desired frequency or frequency range.

[0086] Configuration of the inductive loop 620 may be adjusted as necessary. The inductive loop 620 is configured to create an inductive load matching with the capacitive load of the integrated circuit 610 or a chip. For example, geometric characteristics (e.g., the count of turns, the turn radius, the height of each turn, the distance in consecutive turns, the bend angle of each turn, the depth of each turn, the trace length, or the like) may be adjusted to match the impedance of the integrated circuit 610. For Example, the different geometric characteristics may be incorporated in the inductive loops 116B and 116C to match impedances of different integrated circuits 114B and 114C, respectively. Due to the inductive loop 620, the antenna 400 behaves as a dipole antenna with inductive impedance.

[0087] In other implementations, the RFID label 600 may include the antenna having configuration like the antenna 400 shown in FIGs. 6-7. The antenna 400 may have the loops, wherein the antenna 400 self-crosses at only one point per loop. In other implementations, the antenna 400 of the label 600 may have one or more crossing loops, wherein the antenna 400 selfcrosses at more than one point per loop.

[0088] Referring to FIG. 9, width of the inductive loop 620 may be shorter than width of the antenna 400. The inductive loop 620 is electronically coupled to the antenna 400 at multiple locations. Trace width of the inductive loop 620 is determined such that the label 600 can survive one or more industrial wash cycles. The label 600 shown in FIG. 9 is robust to vertical and horizontal location of the inductive loop 620 inside the antenna 400, thereby making the label 600 suitable for mass production. The integrated circuit 610 is placed such that sufficient space is available for the Marker, Optical Sensor, and fiducials.

[0089] Referring to FIG. 10, the inductive loop 620 may have at least one meander-shaped portion 640. The meander-shaped portion 640 makes the overall length of the inductive loop 620 longer. Length of the inductive loop 620 can be altered to create the desired inductive value without increasing the overall area of the inductive loop 620.

[0090] In some implementations, the inductive loop 620 may have configuration similar to the inductive loops 116A, 116B, 116C shown in FIGs. 1-3 and described in foregoing paragraphs of the present disclosure. However, it is to be noted that the inductive loop 620 may have any other suitable configuration.

[0091] Referring to FIG. 11, another configuration of the inductive loop 620 with at least one meander-shaped portion 640 is shown. In this implementation, a width of the inductive loop 620 is shorter than width of the antenna 400.

[0092] Referring to FIG. 12, another implementation of the label 600 is shown. The label 600 includes the antenna 400, wherein the antenna 400 includes one or more loops 650 having spiral shape. The loops 650 may be concentric loops. It is to be noted that number of spirals of the antenna400 can vary to achieve desired performance. The inductive loop 620 may have at least one meander-shaped portion 640. However, any other suitable inductive loop (for example, the inductive loops described in foregoing paragraphs) may be implemented in the label 600 shown in FIG. 12.

[0093] A trace length of the inductive loop 620, a count of turns, a height of each turn, a bend angle of each turn, a depth of each turn, and a radius of curvature of each turn are set to match an impedance of the integrated circuit 610.

[0094] FIG. 13 shows one example of an inventory management or security system 990 usable with aspects of the disclosure. A RFID interface 900 may be configured to read and / or write to an RFID 968 of an article 960 and / or provide an electromagnetic interrogation pulse. The RFID 968 may be analogous with or identical to the RFID label 100 described above, and may include any one or combination of the integrated circuit 114A, 114B, 114C, and / or 610, described above, the inductive loops 116A, 116B, 116C, and / or 620 and / or the antenna 400 described above. For example, the security or inventory management system 990 may track an article 960 stored at a location, and may include one or more security sensors 972 near a monitoring point 974 that detects when the article 960 having the RFID security tag 968 attached thereto is taken past the security sensor 972 and outside of the location 970 through the monitoring point 974. For instance, the security system 980 may be an electronic article surveillance system. The security sensor 972 may include one or more antenna configured to transmit a signal and / or an electromagnetic interrogation pulse to the security tag 960 or in an area of the entry / exit point 974 and to listen for a response signal from the security tag 960, wherein the response signal or a lack of such response signal indicates the security tag 960 is deactivated, such as when the article 968 to which the security tag 960 is attached has been paid for in a transaction 976 with a transaction terminal 978. For instance, the transaction terminal 978 is connected to a RFID reader and / or writer 900 and may be connected to a transaction system 980, such as via a wired and / or wireless communication network 982, and may include a point of sale terminal 984, which includes a local or remote computer connected to the transaction system 980 via the communication network 982 and / or a mobile communication device 986, such as a cell phone or tablet, connected to the transactionsystem 980 via the communication network 982, or any other type of computer device. In some cases, the transaction system 980 may be a payment system, such as but not limited to an automated clearing house system.

[0095] It is noted that the aforementioned example is not limited. The RFID tag system described above may include any one or combination of the concepts described above for inventory tracking (e.g., during the production, shipping, and / or any other known movements of products or goods through the manufacturing or supply chain).

[0096] As noted above, the RFID tag system may include an integrated circuit (e.g., 114 A, 114b, 114C and / or 610). The integrated circuit my include a microcontroller, which may include any one or combination of the features described below with respect to FIG. 14. FIG. 14 shows an example microcontroller 1100 shown in representative block diagram form. In FIG. 13, the controller 1100 includes a CPU 1102, clock 1104, RAM 1108, ROM 1110, a timer 1112, a BUS controller 1114, an interface 1116, and an analog-to-digital converter (ADC) 1118 interconnected via a BUS 1106. The CPU 1102 may be implemented as one or more single core or multi-core processors, and receive signals from an interrupt controller 1120 and a clock 1104. The clock 1104 may set the operating frequency of the entire microcontroller 1100 and may include one or more crystal oscillators having predetermined frequencies. Alternatively, the clock 1104 may receive an external clock signal. The interrupt controller 1120 may also send interrupt signals to the CPU, to suspend CPU operations. The interrupt controller 1120 may transmit an interrupt signal to the CPU when an event requires immediate CPU attention.

[0097] The RAM 1108 may include one or more Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data-Rate Random Access Memory (DDR SDRAM), or other suitable volatile memory. The Read-only Memory (ROM) 1010 may include one or more Programmable Readonly Memory (PROM), Erasable Programmable Read-only Memory (EPROM), Electronically Erasable Programmable Read-only memory (EEPROM), flash memory, or other types of nonvolatile memory.

[0098] The timer 1112 may keep time and / or calculate the amount of time between events occurring within the controller 1100, count the number of events, and / or generate baud rate for communication transfer. The BUS controller 1114 may prioritize BUS usage within the controller 1100. The ADC 1118 may allow the controller 1100 to send out pulses to signal other devices.

[0099] The interface 1016 may comprise an input / output device that allows the controller 1100 to exchange information with the antenna for example.

[0100] It is noted that the aforementioned example microcontroller is provided as an example, components may be added or omitted as required. Further, the integrated circuits described throughout may include features from or may comprise any known controller or microcontroller.

[0101] The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The implementations of the present disclosure can be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Implementations within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

[0102] Additional aspects of the disclosure are described in the clauses that follow. 1

[0103] Clause 1. A radio frequency identification (RFID) label, comprising: an RFID transponder with an integrated circuit; an inductive loop electronically coupled to the integrated circuit, and: an antenna comprising one or more loops, each loop having one or more crossing points where portions of the antenna are in contact with each other, and the antenna having an insulated coating to prevent physical contact of conductive material of the antenna at the one or more crossing points.

[0104] Clause 2. The RFID label of clause 1, wherein the portions of the antenna in contact with each other at the one or more crossing points correspond to same loop of the one or more loops.

[0105] Clause 3. The RFID label of any of the preceding clauses, wherein the one or more loops comprise a first loop and a second loop, wherein the portions of the antenna in contact with each other at the one or more crossing points correspond with the first loop and the second loop.

[0106] Clause 4. The RFID label of any of the preceding clauses, wherein the antenna is a dipole antenna having a first section and a second section.

[0107] Clause 5. The RFID label of any of the preceding clauses, wherein the first section and the second section are connected via at least one curve segment.

[0108] Clause 6. The RFID label of any of the preceding clauses, wherein the first section and the second section are connected via at least one straight segment.

[0109] Clause 7. The RFID label of any of the preceding clauses, wherein the one or more loops are helical.

[0110] Clause 8. The RFID label of any of the preceding clauses, wherein the one or more loops are spiral.

[0111] Clause 9. The RFID label of any of the preceding clauses, wherein the inductive loop couples the antenna to the integrated circuit.

[0112] Clause 10. The RFID label of any of the preceding clauses, wherein the inductive loop has at least one meander-shaped portion.

[0113] Clause 11. A radio frequency identification (RFID) label, comprising: an RFID transponder comprising: an integrated circuit; an inductive loop electronically coupled to the integrated circuit, the inductive loop having at least one meander-shaped portion; and an antenna coupled to the RFID transponder.

[0114] Clause 12. The RFID label of clause 11, wherein the inductive loop is configured to match an impedance of the integrated circuit.

[0115] Clause 13. The RFID label of any of the preceding clauses, wherein the integrated circuit has capacitive impedance, and the inductive loop is configured to match the capacitive impedance.

[0116] Clause 14. The RFID label of any of the preceding clauses, wherein the inductive loop comprises a first arm segment and a second arm segment, and wherein at least one of the first arm segment and the second arm segment includes the at least one meander-shaped portion.

[0117] Clause 15. The RFID label of any of the preceding clauses, wherein the at least one meander-shaped portion includes one or more turns.

[0118] Clause 16. The RFID label of any of the preceding clauses, wherein a trace length of the inductive loop, a count of turns, a height of each turn, a bend angle of each turn, a depth of each turn, and a radius of curvature of each turn are set to match an impedance of the integrated circuit.

[0119] Clause 17. The RFID label of any of the preceding clauses, wherein a trace width of the inductive loop is set to make the RFID label withstand one or more wash cycles.

[0120] Clause 18. The RFID label of any of the preceding clauses, wherein the inductive loop is formed from a combination of a plurality of conductive materials.

[0121] Clause 19. The RFID label of any of the preceding clauses, further comprising a backing layer such that the RFID transponder and the antenna are provided on the backing layer.

[0122] Clause 20. A radio frequency identification (RFID) transponder, comprising: an integrated circuit; an inductive loop electronically coupled to the integrated circuit to match an impedance of the integrated circuit, the inductive loop having at least one meander-shaped portion; and an encapsulation portion encapsulating the integrated circuit and the inductive loop.

[0123] The construction and arrangement of the systems and methods as shown in the various implementations are illustrative only. Although only a few implementations have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements can be reversed or otherwise varied, and the nature or number of discrete elements or positions can be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps can be varied or re-sequenced according to alternative implementations. Other substitutions, modifications, changes, and omissions can be made in the design, operating conditions and arrangement of the implementations without departing from the scope of the present disclosure.

[0124] Although the figures show a specific order of method steps, the order of the steps may differ from what is depicted. Also, two or more steps can be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish the various connection steps, processing steps, comparison steps and decision steps.

Claims

CLAIMS1. A radio frequency identification (RFID) label, comprising: an RFID transponder with an integrated circuit; an inductive loop electronically coupled to the integrated circuit, and: an antenna comprising one or more loops, each loop having one or more crossing points where portions of the antenna are in contact with each other, and the antenna having an insulated coating to prevent physical contact of conductive material of the antenna at the one or more crossing points.

2. The RFID label of claim 1, wherein the portions of the antenna in contact with each other at the one or more crossing points correspond to same loop of the one or more loops.

3. The RFID label of claim 1, wherein the one or more loops comprise a first loop and a second loop, wherein the portions of the antenna in contact with each other at the one or more crossing points correspond with the first loop and the second loop.

4. The RFID label of claim 1, wherein the antenna is a dipole antenna having a first section and a second section.

5. The RFID label of claim 4, wherein the first section and the second section are connected via at least one curve segment.

6. The RFID label of claim 4, wherein the first section and the second section are connected via at least one straight segment.

7. The RFID label of claim 1, wherein the one or more loops are helical.

8. The RFID label of claim 1, wherein the one or more loops are spiral.

9. The RFID label of claim 1, wherein the inductive loop couples the antenna to the integrated circuit.

10. The RFID label of claim 9, wherein the inductive loop has at least one meander- shaped portion.

11. A radio frequency identification (RFID) label, comprising:an RFID transponder comprising: an integrated circuit; an inductive loop electronically coupled to the integrated circuit, the inductive loop having at least one meander-shaped portion; and an antenna coupled to the RFID transponder.

12. The RFID label of claim 11, wherein the inductive loop is configured to match an impedance of the integrated circuit.

13. The RFID label of claim 12, wherein the integrated circuit has capacitive impedance, and the inductive loop is configured to match the capacitive impedance.

14. The RFID label of claim 11, wherein the inductive loop comprises a first arm segment and a second arm segment, and wherein at least one of the first arm segment and the second arm segment includes the at least one meander-shaped portion.

15. The RFID label of claim 11, wherein the at least one meander-shaped portion includes one or more turns.

16. The RFID label of claim 15, wherein a trace length of the inductive loop, a count of turns, a height of each turn, a bend angle of each turn, a depth of each turn, and a radius of curvature of each turn are set to match an impedance of the integrated circuit.

17. The RFID label of claim 11, wherein a trace width of the inductive loop is set to make the RFID label withstand one or more wash cycles.

18. The RFID label of claim 11, wherein the inductive loop is formed from a combination of a plurality of conductive materials.

19. The RFID label of claim 11 , further comprising a backing layer such that the RFID transponder and the antenna are provided on the backing layer.

0. A radio frequency identification (RFID) transponder, comprising: an integrated circuit; an inductive loop electronically coupled to the integrated circuit to match an impedance of the integrated circuit, the inductive loop having at least one meandershaped portion; and an encapsulation portion encapsulating the integrated circuit and the inductive loop.

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