Booster antenna arrangement for an RFID chip arrangement and RFID system with such a booster antenna arrangement

Abstract

The present disclosure relates in various aspects to a booster antenna arrangement for an RFID chip arrangement and to an RFID system including such a booster antenna arrangement. In illustrative embodiments a booster antenna arrangement for an RFID chip arrangement is provided, the booster antenna arrangement comprising a first antenna arrangement configured for communication with an RFID reader and a second antenna arrangement configured for communication with at least one RFID tag. The second antenna arrangement comprises two or more second antenna coils which are electrically interconnected, each of the two or more second antenna coils being configured for emitting electromagnetic radiation to and receiving electromagnetic radiation from a dedicated one of the at least one RFID tag.

Description

[0001] Booster Antenna Arrangement for an RFID Chip Arrangement and RFID system with such a Booster Antenna Arrangement

[0002] Field of the Disclosure

[0003] The present disclosure relates in various aspects to a booster antenna arrangement for an RFID chip arrangement and to an RFID system including such a booster antenna arrangement.

[0004] Technological Background

[0005] Radio Frequency Identification (RFID) technology, particularly in the high-frequency (HF) range at 13.56 MHz, is widely used in applications such as contactless payment systems, public transportation cards, access control, and inventory tracking. Its key advantage lies in its ability to enable wireless data exchange between a reader and a transponder without requiring direct contact or a clear line of sight. However, as RFID technology continues to evolve, the demand for smaller and more compact RFID transponders has introduced significant technical challenges that impact their readability, energy efficiency, and signal reliability when used with standard readers.

[0006] Miniaturized HF RFID transponders face fundamental physical and electromagnetic constraints that limit their ability to efficiently harvest energy, establish reliable inductive coupling, and maintain sufficient signal strength for communication. The primary issue stems from their small antenna size, which directly affects their ability to capture and utilize energy from the reader’s electromagnetic field. Additionally, their shortened read range and increased sensitivity to positioning and orientation make them difficult to use in real-world scenarios where precise alignment is not always possible. Understanding these challenges is critical to improving RFID performance and ensuring its continued applicability in increasingly compact applications.

[0007] In general, HF RFID systems operate using near-field inductive coupling, a method in which a reader generates an alternating magnetic field to power and communicate with a transponder. This process occurs in three main stages. First, the RFID reader emits an alternating current through a loop antenna, creating an oscillating magnetic field around it. When a nearby transponder, also equipped with a coil antenna, enters this field, the changing magnetic flux induces an electromotive force (EMF) in its antenna coil, generating an electric current. This induced current serves as the primary power source for passive HF RFID transponders, which lack internal batteries. Once powered, the transponder modulates its response by varying its electrical impedance, altering the load on the reader’s field in a process known as load modulation. The reader detects these variations and decodes the transponder’s unique identifier and data, completing the communication process. The efficiency of this energy transfer and data exchange depends on the

[0008] 25.3.2025strength of the reader’s magnetic field, the size and geometry of both antennas, and the distance between them.

[0009] For optimal energy transfer, HF RFID transponders rely on a precise resonance at 13.56 MHz. As transponders become smaller, maintaining this resonance becomes challenging due to variations in inductance and capacitance, leading to frequency detuning and inconsistent read performance. Typically, HF RFID is limited to short-range applications, with effective read distances ranging from a few centimeters to about one meter, however, strongly depending on the transponder’s size and environmental conditions. Given this operational framework, the size of the transponder’s antenna plays a crucial role in determining its performance. Smaller transponders inherently face lower power harvesting efficiency, leading to shortened read ranges and increased reading failures in standard HF RFID systems.

[0010] The transponder’s antenna serves a dual purpose, as it must capture energy from the reader’s electromagnetic field and transmit data back through load modulation. When the transponder is miniaturized, several key challenges arise. A small transponder has a shorter antenna coil with fewer turns, reducing its inductance and ability to absorb energy from the reader’s field. As a result, the transponder may fail to accumulate enough energy to activate and respond reliably. Additionally, the smaller surface area and thinner conductive materials in small transponders contribute to higher Ohmic resistance, leading to energy dissipation as heat rather than efficient power transfer. This results in weaker backscattered signals, making it difficult for the reader to detect and decode the transponder’s response.

[0011] The effectiveness of HF RFID technology depends on the strength of the inductive coupling between the reader and transponder. Small transponders inherently exhibit poor coupling efficiency, leading to shorter read distances and higher sensitivity to misalignment. The efficiency of power transfer in HF RFID depends on mutual inductance, which is proportional to the size and orientation of both antennas. As transponders become smaller, their mutual inductance with the reader decreases, significantly reducing the amount of power that can be transferred. Furthermore, the reader’s electromagnetic field follows the inverse square law, meaning its strength drops exponentially with distance. Since small transponders already struggle to harvest power, this rapid field decay further restricts their operational range, often limiting them to just a few millimeters to a few centimeters. Larger transponders typically allow some flexibility in positioning relative to the reader’s antenna. However, small transponders require highly precise alignment to function properly. Even slight misalignment can result in a complete loss of signal, making their use impractical in dynamic environments where objects move or rotate unpredictably.

[0012] 25.3.2025The miniaturization of HF RFID transponders introduces significant technical challenges that stem from fundamental electromagnetic and physical constraints. Their smaller antenna size, limited power harvesting capacity, weak inductive coupling, and reduced read range make them inherently less efficient than their larger counterparts. In real-world applications, these challenges lead to higher read failure rates, increased sensitivity to positioning, and restricted usability in environments where precise alignment is not guaranteed. Understanding these limitations is essential for optimizing HF RFID performance and developing new approaches to improve the readability of small transponders. As the demand for compact and embedded RFID solutions continues to grow, overcoming these challenges is crucial for ensuring the reliability and effectiveness of HF RFID technology across a wide range of applications.

[0013] It is an object of the present application to provide a way of enhancing functionality of (HF) RFID readers, such as in scenarios where small and / or embedded tags are used and / or direct coupling with a reader’s field is insufficient for reliable operation.

[0014] Summary of the Disclosure

[0015] The issues and problems described in the context of the technological background of the present disclosure are at least partially resolved by a booster antenna for an RFID chip arrangement in accordance with claim 1 and an RFID system for reading an RFID chip arrangement in accordance with claim 19. Further advantageous embodiments are defined in the dependent claims 2 to 18 and 20 to 22.

[0016] In a first aspect, a booster antenna arrangement for an RFID chip arrangement is provided. In the illustrative embodiments herein, the booster antenna arrangement comprises a first antenna arrangement configured for communication with an RFID reader and a second antenna arrangement configured for communication with at least one RFID tag. The second antenna arrangement comprises two or more second antenna coils which are electrically interconnected, each of the two or more second antenna coils being configured for emitting electromagnetic radiation to and receiving electromagnetic radiation from a dedicated one of the at least one RFID tag. For example, the second antenna arrangement may comprise two second antenna coils or three second antenna coils or four second antenna coils or five second antenna coils or six second antenna coils or seven second antenna coils. However, the number of second antenna coils may not be considered as particularly limited and more than seven second antenna coils may be considered, such as more than ten antenna coils. In general, a number of N second antenna coils may be provided, with N representing an integer number greater than one. Accordingly, the reading range of one or more small tags, such as HF transponders, while presenting at the same time the possibility of reading and / or recognizing several small RFID tags, such as HF transponders, by a single reader.

[0017] 25.3.2025Such a booster antenna arrangement may allow for providing a passive booster antenna as a specialized component designed to enhance the reading range of HF RFID systems by improving the inductive coupling between an RFID reader and a small or weak target RFID tag to be read by the RFID reader. Unlike active solutions that require additional power sources or amplification, a passive booster antenna operates purely through electromagnetic field interactions, making it an efficient and cost-effective method for extending the operational range of HF RFID readers. In illustrative embodiments of the first aspect, the first antenna arrangement and / or the second antenna arrangement may comprise one or more booster antennas each of which consisting of a loop or coil of conductive material, typically copper or aluminum, that is tuned to resonate at the same frequency as the HF RFID system, e.g., at 13.56 MHz. For examples, the loop or coil may have multiple turns formed in accordance with wire embedding technology or by etching or printing the loop or coil. The geometry and size of the booster antenna may be designed to maximize its interaction with the reader’s magnetic field. In some special illustrative examples, the booster antenna may be integrated into a printed circuit board (PCB) or constructed using thin conductive traces on flexible substrates, allowing it to be embedded in various environments. In some special illustrative examples, the booster antenna may take the form of a planar coil similar to an RFID reader’s antenna but larger and more efficiently coupled to the reader’s field, optionally further including additional coupling elements, such as capacitive matching circuits and / or ferrite core elements etc., to further optimize the resonance and energy transfer efficiency. In some illustrative examples, the first antenna arrangement and the second antenna arrangement may be arranged out of plane such that the second antenna arrangement may define a plane which is not coincident or identical with a plane defined by the first antenna arrangement. In other words, the first and second antenna arrangements may be located offset with respect to each other in a substrate or a card body along a width dimension of the substrate or card body, where the width dimension may be a smallest geometrical dimension of dimension of the substrate or card body measured in a Cartesian coordinate system of the substrate or card body. The width dimension may be perpendicular to a plane defined by a turn of the first antenna arrangement and / or a turn of the second antenna arrangement.

[0018] However, an HF RFID system is not particularly limiting and the booster antenna arrangement may be designed to resonate at any operating frequency of the RFID system, such as at an LF (Low Frequency) in a range from about 125 to about 134 kHz or at UHF (Ultra High Frequency in a range from about 860 to about 960 MHz instead. Accordingly, whenever reference is made to HF RFID herein, it is only be understood as an illustration and no limitation is intended, the RFID frequency alternatively being of the LF or UHF range.

[0019] 25.3.2025The booster antenna arrangement of the first aspect is designed to interact with both of an RFID reader and at least one RFID tag by acting as an intermediary that modifies and enhances the RFID reader’s electromagnetic field. During operation of the booster antenna arrangement, i.e., when the booster antenna arrangement is exposed to an HF RFID reader emitting an alternating magnetic field, the booster antenna arrangement captures and redistributes this energy by creating a secondary magnetic field that extends the effective range of the reader’s signal. This redistribution occurs due to the inductive coupling between the reader’s antenna and the booster antenna, which in turn induces a stronger and more uniform field in the space where a target RFID tag is located. As a result, the target RFID tag, which may have a very small antenna or be positioned in a suboptimal location relative to the reader, experiences an increased level of electromagnetic energy. This enhanced energy transfer allows the tag to harvest sufficient power to activate its internal circuitry, improving the likelihood of successful data transmission back to the reader.

[0020] Additionally, the booster antenna arrangement may allow improving signal consistency by reducing field variations that can occur due to interference from surrounding materials or environmental factors. Since HF RFID operates in the near-field region, the efficiency of energy transfer is highly dependent on the alignment and distance between reader and tag. The booster antenna arrangement of the first aspect helps mitigate issues related to misalignment by effectively expanding the region in which a tag can receive adequate power. This is particularly beneficial for applications where tags may not always be perfectly positioned relative to a reader’s antenna, such as in retail packaging, access control systems, or industrial asset tracking.

[0021] The first antenna arrangement may be configured for having a coupling factor of near to 1 to a reader antenna, e.g., having a geometry and / or size comparable to at least one of geometry and size of a reader antenna. Herein, “near” and “comparable” may be understood as indicating a deviation of at most 30%, preferably at most 20% or at most 15% or at most 10% or at most 5%. The second antenna arrangement may be small relative to the first antenna arrangement in that a maximum dimension of the two or more second antenna coils (that is a maximum dimension of the dimensions the two or more second antenna coils) is smaller than a smallest dimension of the first antenna arrangement. Herein, dimensions of the first and second antenna arrangements may be considered as dimensions measured along two perpendicular directions in a plane defined by a virtual plane spanned or approximated such that the antenna arrangement is at least partially routed in the virtual plane to a best degree of approximation. The dimensions may be related to a dedicated coordinate system associated with at least one or each of the first antenna arrangement and the two or more second antenna coils. For example, a ratio of the maximum dimension to the

[0022] 25.3.2025smallest dimension may be at least 1.5 or at least 2 or at least 3 or at least 4 or at least 8 or at least 10. In some special illustrative examples, the ratio may be in a range from about 2 to about 10, such as in a range from about 2 to about 8 or from a about 2 to about 5 or in a range from about 2 to about 4. In general, any intersection of two or more of these closed intervals and / or semi-closed intervals may be considered. The term “about” with respect to turns means that at least one turn is not a complete turn, such as at least one of an initial turn and a final turn of a coil. Herein, a dimension of a coil indicates a measured distance between two points of a coil along a certain direction, the two points of the coil having a maximum separation (e.g., at outermost turn of coil).

[0023] The booster antenna arrangement of the first aspect provides for second antenna arrangements with multiple second antenna coils at a secondary side of the booster antenna arrangement for communicating with a target RFID tag. Accordingly, a magnetic coupling to a target RFID tag may be increased, thereby increasing the chances of better aligning an RFID reader with the RFID tag. Furthermore, enhancing inductive coupling allows for a more efficient energy transfer to the RFID tag. In this way, an extended read range is achieved, where the electromagnetic field of generated by an RFID reader to which the booster antenna arrangement is exposed, is distributed more effectively, allowing a target tag to receive more power from an RFID reader, which is especially useful in scenarios where tag orientation may vary.

[0024] Furthermore, the booster antenna arrangement of the first aspect provide enhanced coverage for misaligned tags because, if a target RFID tag is not perfectly positioned, at least one coil is more likely to maintain a strong coupling with the tag which may be particularly beneficial in dynamic environments where tag positions are unpredictable. This design also offers better tolerance to orientation variations.

[0025] Moreover, the booster antenna arrangement of the first aspect facilitates multi-tag communication. In some illustrative embodiments of the first aspect, the two or more second antenna coils may be electrically connected in series. That is, the antenna coils of the booster antenna arrangement that couple to a target RFID tag (rather than those coupling to an RFID reader, i.e., coils of the first antenna arrangement) allow enhancing power transfer, signal stability, and system efficiency. Since each coil in a series configuration contributes to the total voltage, any target RFID tag coupled to the second antenna arrangement may receive a stronger signal which is beneficial in passive RFID systems where target tags rely solely on energy from a reader's signal. Furthermore, impedance matching between the booster antenna arrangement and a target RFID tag may be improved by tuning the inductance of the series-connected coils, the system can achieve a better impedance match, leading to more efficient power transfer because a well-matched impedance

[0026] 25.3.2025minimizes energy losses and ensures that the tag receives the maximum possible power. The two or more antenna coils in series connection maintain a consistent current flow across all coils, thereby stabilizing the electromagnetic field distribution and increasing reliability in applications where RFID tags might be positioned at varying distances or orientations relative to the booster antenna arrangement. Also, a stable field distribution reduces signal fluctuations, ensuring that target tags can be read more consistently. Another advantage is extended effective read range for RFID tags resulting from an increased induced voltage and optimized impedance matching, allowing target tags to operate at greater distances from a reader.

[0027] In some other illustrative embodiments of the first aspect, the two or more second antenna coils may be electrically connected in series to the first antenna arrangement. Accordingly, power transfer, signal stability, and system efficiency may be enhanced since each coil in a series configuration contributes to the total voltage, any second antenna coil of the second antenna arrangement may receive a stronger signal from the first antenna arrangement. Furthermore, impedance matching between the booster antenna arrangement and a target RFID tag may be improved by tuning the inductance of the series-connected coils. The two or more antenna coils in series connection maintain a consistent current flow across all coils, thereby stabilizing the electromagnetic field distribution in each of the first and second antenna arrangements.

[0028] In some other illustrative embodiments, the first antenna arrangement may comprise two first antenna coils. This dual primary coil structure of the booster antenna arrangement with two first antenna coils provides a more stable and consistent signal, reducing variations in tag readability due to environmental changes, material interference, or tag orientation. This is especially beneficial in applications such as smart shelves, access control, and inventory tracking, where reliable RFID communication is critical. For example, the first antenna arrangement may at most or only comprise two first antenna coils configured for coupling to an RFID reader. Such a booster antenna arrangement with multiple coils coupling to an RFID reader enhances signal reception and improves read range by efficiently capturing and redistributing energy. This setup minimizes dead zones, ensuring reliable communication with RFID tags even in varying orientations or positions. With multiple coils, the system becomes less sensitive to reader misalignment, allowing for flexible placement while maintaining strong performance. The design also supports better energy distribution, ensuring tags receive consistent power across different locations. Additionally, multiple coils can accommodate varying reader frequencies or polarization orientations, increasing compatibility with different RFID systems. Improved efficiency and reduced energy loss contribute to more reliable operation, even in challenging conditions such as interference-prone or metallic environments. The system's adaptability allows it to be used in various applications, including asset

[0029] 25.3.2025tracking, access control, and industrial automation. Ultimately, using multiple reader-coupling coils in the booster antenna arrangement allows robust, scalable, and effective RFID systems. Upon splitting the first antenna arrangement into multiple first antenna coils, a number of winding turns in each first antenna coil may be in a range from about 1 to about 5 turns, further contributing to scalable RFID systems.

[0030] In some illustrative examples of the above embodiments, the two or more second antenna coils may be connected electrically in series between the first antenna coils. In this booster antenna arrangement with two first antenna coils configured for coupling to an RFID reader and multiple second antenna coils configured for coupling to an RFID tag, where the second antenna coils are connected in series between the two first antenna coils, several advantages in RFID systems are achieved because this configuration optimize energy transfer, enhances read range, and ensures reliable tag communication. The two first antenna coils effectively capture energy from the RFID reader, creating a strong electromagnetic field. This energy is then efficiently transferred to the series-connected second antenna coils, which distribute it to the RFID tags. By placing the second coils in series between the first coils, the induced voltage is increased, allowing passive RFID tags to receive a stronger signal. Another benefit is extended read range and improved tag activation. The combination of two primary coils ensures that energy capture from the reader is maximized, while the series connection of the secondary coils provides a higher induced voltage across the RFID tags. This setup allows for reliable reading of tags at greater distances, making it particularly useful in applications where tags are not always positioned optimally.

[0031] In some other illustrative embodiments of the first aspect, the two or more second antenna coils may be of substantially identical shape and / or size. Accordingly, such a booster antenna arrangement with multiple identical antenna coils exclusively coupling to RFID tags ensures uniform energy distribution, leading to consistent tag readability and reducing performance variations. This setup improves multi-tag readability by creating a stable electromagnetic field, making it ideal for applications like smart shelves and asset tracking. The identical coil design simplifies impedance matching and tuning, enhancing power transfer efficiency while minimizing energy loss. Additionally, using identical coils reduces manufacturing complexity and cost, allowing for mass production and easier system integration. The design also increases robustness against environmental variations, ensuring stable performance despite temperature changes or interference. By eliminating dead zones, this configuration guarantees uniform tag activation across the entire read area. Its modular scalability allows for easy expansion by adding more identical coils without requiring sys-

[0032] 25.3.2025tem redesign. Overall, this design optimizes RFID system efficiency, reliability, and cost-effectiveness, making it suitable for various applications requiring consistent and high-performance tag reading.

[0033] In some other illustrative embodiments, the first antenna arrangement may comprise two wiring portions which determine capacity and inductance of the first antenna arrangement. That is, an outer wiring portion of the first antenna arrangement may be identified with an antenna wiring portion of the first antenna arrangement having open ends of the antenna wiring, thereby the outer wiring portion determining a capacity of the first antenna arrangement. The outer wiring portion has at least two wiring track line portions routed to extend along each other for generating a contribution to the capacitance of the first antenna arrangement such that the capacitance of the first antenna arrangement is substantially determined by the capacitance of the outer wiring portion, wherein substantially determined indicates that the capacitance of the outer wiring portion is at least 70% or at least 80% or at least 90% or at least 95% of the capacitance of the first antenna arrangement. Furthermore, an inductance of the outer wiring portion may be substantially small when compared to the inductance of the first antenna arrangement, such as smaller than 20% or smaller than 10% or smaller than 5 % of the inductance of the first antenna arrangement. The first antenna arrangement further comprises an inner wiring portion which is at least partially encircled by the outer wiring portion, the inner wiring portion determining an inductance of the first antenna arrangement. The inner wiring portion has a contribution to the inductance of the first antenna arrangement such that the inductance of the first antenna arrangement is substantially determined by the inductance of the outer wiring portion, wherein substantially determined indicates that the inductance of the outer wiring portion is at least 70% or at least 80% or at least 90% or at least 95% of the inductance of the first antenna arrangement. Furthermore, a capacity of the inner wiring portion may be substantially small when compared to the capacity of the first antenna arrangement, such as smaller than 20% or smaller than 10% or smaller than 5 % of the capacity of the first antenna arrangement. In some illustrative examples herein, each of the wiring portions may have about 1 to 20 turns. Additionally or alternatively, the two or more second antenna coils may be connected electrically in series between the wiring portions of the first antenna arrangement. In some other illustrative embodiments of the first aspect, the first and second antenna arrangements may be formed of windings wound with identical winding orientation. Accordingly, such a booster antenna arrangement with multiple antenna coils wound in the same orientation ensures consistent electromagnetic field alignment, enhancing energy transfer to RFID tags. This uniform winding prevents destructive interference and improves power transfer efficiency, allowing passive

[0034] 25.3.2025RFID tags to receive stronger signals and increasing read range. The simplified tuning and impedance matching make system design more predictable and easier to optimize. With all coils generating reinforcing magnetic fields, signal distortion and interference are minimized, leading to more reliable tag activation across different positions. This setup also enhances multi-tag readability, ensuring multiple RFID tags can be detected simultaneously with minimal errors. By reducing eddy currents and parasitic losses, performance remains stable even in challenging environments with metal surfaces. Additionally, the uniform coil orientation makes the booster antenna scalable and adaptable, allowing easy expansion without complex adjustments. Overall, this configuration results in a more efficient, reliable, and high-performance RFID system suitable for applications requiring strong and consistent tag detection.

[0035] In some other illustrative embodiments of the first aspect, the first and second antenna arrangements may be formed of a single continuous antenna wire. Accordingly, such a booster antenna arrangement having first and second antenna arrangements which are both together formed from a single continuous wire improves energy efficiency by minimizing electrical resistance and reducing power loss. Since there are no connection points or solder joints, it offers greater reliability by eliminating potential failure points and making the antenna more durable. The simplified manufacturing and assembly process lowers costs and reduces complexity, ensuring consistent performance. With an uninterrupted current flow, the antenna generates a stable and uniform electromagnetic field, improving RFID tag readability. The absence of breaks also reduces parasitic effects like unwanted inductive coupling and signal distortions, enhancing overall system efficiency. This design is particularly beneficial in environments with metallic surfaces or interference, where signal clarity is crucial. Additionally, the flexibility and scalability of a single-wire antenna make it easy to adapt to different RFID applications without complex modifications. Its robust construction ensures long-term performance with minimal maintenance. Overall, using a single continuous wire results in higher efficiency, reliability, and adaptability, making it a superior choice for RFID booster antennas.

[0036] In some other illustrative embodiments of the first aspect, the first antenna arrangement may have two open ends. Accordingly, such a booster antenna arrangement with an open-ended first antenna arrangement that is configured for coupling to an RFID reader enhances energy transfer efficiency by minimizing direct current losses and improving inductive coupling. The open ends help optimize impedance matching, ensuring efficient power transfer and reducing energy losses. This configuration also reduces interference and signal reflections, leading to a more stable and well-defined electromagnetic field that enhances RFID tag readability. Herein, the open ends may

[0037] 25.3.2025serve as a capacitance for substantially determining the capacitance of the first antenna arrangement. In some very special illustrative examples with the first antenna arrangement comprising two or more first antenna coils, the antenna coil having two open ends may be regarded as a capacitance determining wire portion routed in a winded wiring track arrangement of plural wire track line portions routed in an intertwined manner, such as a doubly or multifold intertwined spirally shaped routing. Additionally, the flexible design allows the first antenna arrangement to be shaped and positioned for maximum coupling with an RFID reader, making it adaptable to various applications. The open-ended first antenna can also act as a resonant energy collector, passively amplifying the RFID reader’s signal and extending the effective read range for passive RFID tags. This design is particularly useful in space-constrained environments or systems where reader positioning varies. By improving energy efficiency, reducing interference, and extending read range, this configuration makes RFID communication more reliable and effective. For example, the first antenna arrangement may comprise two first antenna coils such that one of the two first antenna coils has a single one of the open ends, while the other one of the two first antenna coils has the other one of the open ends.

[0038] In some other illustrative embodiments of the first aspect, the first and second antenna arrangements may be routed in at least one surface of a card body of a smart card or in at least one surface of a substrate or in at least one surface of a carrier. Accordingly, such a booster antenna arrangement with the first and second antenna arrangements routed within a card body enhances energy transfer efficiency while maintaining a compact and durable design.

[0039] In some other illustrative embodiments of the first aspect, the second antenna arrangement may be partially or completely encircled by the first antenna arrangement. Accordingly, such a booster antenna arrangement with the second antenna arrangement being completely encircled by the first antenna arrangement enhances energy transfer efficiency by maximizing inductive coupling between an RFID reader and an RFID tag. The encircling design creates a stronger and more uniform electromagnetic field, ensuring stable and predictable tag activation. It also helps shield the RFID system from external interference, reducing noise and improving overall performance in environments with high electromagnetic activity. By optimizing impedance matching and minimizing energy losses, the system ensures that the RFID tag consistently receives sufficient power for operation. This configuration also eliminates dead zones and signal variations, improving readability regardless of slight tag position changes. The compact and integrated design is especially beneficial for applications like smart cards, secure access systems, and contactless identification. Additionally, the first antenna arrangement acts as a passive amplifier, extending the RFID tag's read range without requiring extra power. Overall, this design enhances efficiency, reliability, and

[0040] 25.3.2025performance, making it ideal for robust RFID applications requiring consistent and high-quality signal transmission.

[0041] In some other illustrative embodiments of the first aspect, the first antenna arrangement may have one or more windings with a total of less than 50 turns, such as less than 20 turns. For example, the first antenna arrangement may be formed of at least one winding with about 5 to 10 turns each or in total. Accordingly, a scalable booster antenna arrangement may be provided.

[0042] In some other illustrative embodiments of the first aspect, each of the two or more second antenna coils may have a maximum dimension of at most about 15 mm, preferably at most about 10 mm, more preferably at most about 5 mm. Accordingly, such a booster antenna arrangement allows ensuring that energy is efficiently concentrated within a localized area, improving power transfer to small RFID tags that might otherwise struggle to receive sufficient energy from a reader.

[0043] In some other illustrative embodiments of the first aspect, each of the two or more second antenna coils may be configured to emit and receive electromagnetic radiation at a resonance frequency in a range from about 13 to 17 MHz. Accordingly, the booster antenna arrangement may be compatible with HF readers and HF tags.

[0044] In some other illustrative embodiments of the first aspect, the two or more second antenna coils may be separated from each other by at least a maximum dimension of each of the two more second antenna coils. Accordingly, such a booster antenna arrangement with multiple second antenna coils separated by at least their maximum dimension improves electromagnetic field distribution by reducing interference and mutual coupling effects, ensuring efficient energy transfer. This configuration enhances multi-tag readability, allowing multiple RFID tags to be detected reliably without overlapping signals or interference. The spatial separation of the coils improves energy efficiency, preventing excessive inductive coupling and ensuring consistent tag activation. Additionally, the broader coverage area allows for reliable reading of RFID tags placed at different positions, making it ideal for applications like smart shelves and inventory tracking. The design also minimizes dead zones, ensuring that RFID tags positioned between the coils receive sufficient energy for activation. With better scalability, additional second antenna coils can be integrated without negatively affecting system performance. This layout also makes the system more robust against environmental changes and tag misalignment, maintaining consistent read performance. By optimizing energy distribution and improving tag detection accuracy, this configuration enhances RFID system efficiency and reliability for a variety of applications.

[0045] In some other illustrative embodiments of the first aspect, each of the two or more second antenna coils may be separated by at least a maximum dimension of each of the two more second antenna

[0046] 25.3.2025coils from the first antenna arrangement. Accordingly, such a booster antenna arrangement with a first antenna arrangement coupling to an RFID reader and a second antenna arrangement coupling to an RFID tag, where the second antenna coils are separated from the first by at least their maximum dimension, enhances energy transfer efficiency and reduces interference. By increasing the distance between the two arrangements, direct coupling interference is minimized, ensuring a more controlled and efficient power transfer to RFID tags. This separation also improves electromagnetic field distribution, preventing signal distortions and optimizing RFID tag readability. Additionally, impedance matching and resonance tuning are enhanced, reducing power losses and extending the system's effective read range. The design supports multi-tag readability, preventing overlapping electromagnetic fields that could lead to detection errors. Scalability and flexibility are improved, allowing for adjustments or expansions without significantly affecting performance. The minimized dead zones ensure that RFID tags positioned at varying distances still receive a stable and sufficient signal. Furthermore, this separation enhances environmental robustness, making the system more resilient to interference, changes in reader positioning, and surrounding materials. Overall, this configuration improves reliability, efficiency, and adaptability, making it highly effective for advanced RFID applications.

[0047] In a second aspect, an RFID system for reading an RFID chip arrangement is provided. In the illustrative embodiments of the second aspect, the RFID system comprises an RFID reader having a reading antenna arrangement and the booster antenna arrangement of the first aspect. The reading antenna arrangement is configured for communication with the first antenna arrangement. The RFID system of the second aspect provides for a booster antenna arrangement having multiple second antenna coils at a secondary side of the booster antenna arrangement for establishing communication between the RFID reader and a target RFID tag. Accordingly, a magnetic coupling to a target RFID tag may be increased, thereby increasing the chances of better aligning an RFID reader with the RFID tag. Furthermore, enhancing inductive coupling allows for a more efficient energy transfer to the RFID tag. In this way, an extended read range is achieved, where the electromagnetic field of generated by an RFID reader to which the booster antenna arrangement is exposed, is distributed more effectively, allowing a target tag to receive more power from an RFID reader, which is especially useful in scenarios where tag orientation may vary. Furthermore, the booster antenna arrangement of the first aspect provide enhanced coverage for misaligned tags because, if a target RFID tag is not perfectly positioned, at least one coil is more likely to maintain a strong coupling with the tag which may be particularly beneficial in dynamic environments where tag positions are unpredictable. This design also offers better tolerance to orientation variations. Moreover, the booster antenna arrangement of the first aspect facilitates multi-tag communication.

[0048] 25.3.2025In some illustrative embodiments of the second aspect, the booster antenna arrangement may be spatially displaceable relative to the RFID reader with a separation of at least 20 mm. For example, the spatial separation may be in a range from about 20 mm to about 40 mm, such as in a range from about 30 mm to about 40 mm. Accordingly, the booster antenna arrangement allows an increased reading range.

[0049] In some other illustrative embodiments of the second aspect, the RFID system may further comprise at least one RFID chip arrangement with at least one RFID chip. Accordingly, at least one target RFID tag may be provided by means of the at least one RFID chip arrangement.

[0050] In some other illustrative embodiments of the second aspect, the booster antenna arrangement may be integrated with the RFID chip arrangement into a common product body, wherein each of the at least one RFID antenna chip arrangement is arrangeable in alignment with respect to a dedicated one of the two or more second antenna coils. In integrating the booster antenna arrangement into a product body together with RFID chips, where the RFID chips may be arranged close to it, enhances energy transfer efficiency, ensuring RFID chips receive a stronger and more consistent signal. This leads to improved read range and reliability, allowing tags to be detected even at varying angles or distances from the RFID reader. The flexibility of tag placement optimizes performance by reducing signal loss and interference, making it ideal for space-constrained product designs. Additionally, multi-tag readability is enhanced, as the booster antenna distributes energy evenly, preventing signal overlap or dead zones. This setup also increases product durability, as embedding the booster antenna within the product body protects the RFID system from external wear and mechanical damage. The integration simplifies interaction with existing RFID infrastructure, ensuring compatibility with standard RFID readers without additional modifications. By amplifying and redistributing the reader's signal, the booster antenna makes RFID-enabled products more efficient and scalable. Overall, this design improves RFID system performance, reliability, and practicality, making it ideal for applications such as smart packaging, asset tracking, and inventory management.

[0051] In some other illustrative embodiments of the second aspect, the booster antenna arrangement and the RFID chip arrangement may be integrated in different and separable body elements, wherein each of the at least one RFID antenna chip arrangement is arrangeable in alignment with respect to a dedicated one of the two or more second antenna coils. Separating the booster antenna arrangement and RFID chips into different bodies, while allowing them to be arranged close to each other, provides greater flexibility and adaptability in RFID system design. This setup enhances energy transfer efficiency, as RFID chips can be positioned near the booster antenna for

[0052] 25.3.2025optimal inductive coupling while maintaining independent placement. Multi-tag readability is improved, enabling multiple RFID chips to be activated efficiently with a single booster antenna, reducing signal congestion and interference. The system becomes more scalable, allowing for easy expansion by adding more RFID chips without major modifications. Additionally, this separation enhances environmental adaptability, enabling optimal positioning of components to minimize interference from metal surfaces or electronic noise. Durability and maintenance are improved, as damaged RFID chips or booster antennas can be replaced individually without disrupting the entire system. This setup is particularly beneficial in industrial applications, logistics, and inventory tracking, where physical constraints impact RFID performance. By increasing modular adaptability, efficiency, and reliability, this design makes RFID systems more cost-effective and versatile for various applications.

[0053] In a third aspect of the present disclosure, a card having a card body is provided. In the illustrative embodiments of the third aspect, the card further comprises the booster antenna arrangement of the first aspect. The booster antenna arrangement is formed in and / or on the card body. For example, the booster antenna arrangement may be formed at least partially on at least one main surface of the card body (that is, on one of two opposite surfaces of the card body with maximum surface area). Additionally or alternatively, the booster antenna arrangement may be integrated at least partially into the card body. In some illustrative examples, the card body may be the card body of a smart card.

[0054] The person skilled in the art will understand from the present application that overall effectiveness of the booster antenna arrangement may depend on its design parameters, including coil diameter, number of turns, and the quality of the conductive material used. The integration of such a booster antenna arrangement into an RFID system provides a simple yet powerful way to enhance the functionality of HF RFID readers, especially in scenarios where small and / or embedded tags are used and / or direct coupling with a reader’s field is insufficient for reliable operation as will become more clear from the following description.

[0055] Brief Description of the Drawings

[0056] Various illustrative embodiments and other advantages of the various aspects of the present disclosure will become apparent from the detailed description of the accompanying Figures as presented below.

[0057] Figure 1 schematically shows an RFID system in accordance with some illustrative embodiments of the present disclosure.

[0058] 25.3.2025Figure 2 schematically shows a schematic circuit diagram of a booster antenna arrangement in accordance with some illustrative embodiments of the present disclosure.

[0059] The Figures accompanying the present disclosure are only provided for schematically showing some concepts and aspects of the present disclosure without showing all possible details of certain embodiments and without necessarily being actually to scale.

[0060] Detailed Description

[0061] Referring to the Figures, various aspects and illustrative embodiments will be described in greater detail, where the Figures are only schematic and not to scale. The following description is only intended for illustrative purposes and no limitation is intended.

[0062] Fig. 1 schematically shows am RFID system 1 having an RFID reader 2, an RFID target tag 4, and a booster antenna arrangement 6. The RFID reader 2 may be an HF RFID reader emitting electromagnetic radiation in a range from about 13 MHz to about 17 MHz, such as in a range from 13.56 MHz to about 17 MHz, e.g., at 13.56 MHz. However, this does not imply any limitation and the RFID reader 2 may be implemented as an LF or UHF reader instead.

[0063] The booster antenna arrangement 6 comprises a first antenna arrangement 6a acting as an external booster antenna which is configured for communicating with the RFID reader 2. Furthermore, the booster antenna arrangement 6 comprises a second antenna arrangement 6b acting as a coupling inductance having multiple inductance coils or coupling coils which are each configured for communicating with the RFID target tag 4. The booster antenna arrangement 6 further comprises a matching circuit 6c for tuning and adjusting capacitance and inductance of the booster antenna arrangement 6 by one or more inductive and / or capacitive elements. However, this does not imply any limitation and the matching circuit 6c may be included into at least one of the first and second antenna arrangements 6a and 6b by appropriately designing the first and second antenna arrangements 6a and 6b.

[0064] In some illustrative examples, the first antenna arrangement 6a and the second antenna arrangement 6b may be arranged out of plane within a substrate (not illustrated) or carrier (not illustrated) or card body (not illustrated). For example, the second antenna arrangement 6b may define a plane (not illustrated) which may not be coincident or identical with a plane (not illustrated) defined by the first antenna arrangement 6a in the substrate (not illustrated) or carrier (not illustrated) or card body (not illustrated). In other words, the first and second antenna arrangements 6a, 6b may be located offset with respect to each other in the substrate (not illustrated) or carrier (not illustrated) or card body (not illustrated) along a width dimension of the substrate (not illustrated) or carrier (not illustrated) or card body (not illustrated). Generally, the width dimension (not illustrated)

[0065] 25.3.2025may be understood as representing a smallest geometrical dimension of dimension of the substrate (not illustrated) or carrier (not illustrated) or card body (not illustrated) measured in a Cartesian coordinate system of the substrate (not illustrated) or carrier (not illustrated) or card body (not illustrated). The width dimension (not illustrated) may be perpendicular to a plane (not illustrated) defined by a turn (not illustrated) of the first antenna arrangement 6a and / or a turn (not illustrated) of the second antenna arrangement 6b.

[0066] In some illustrative examples herein, the external booster antenna of the first antenna arrangement 6a may consist of multiple printed windings (for example, each having less than 50 turns or less than 20 turns each or in total, such as 4-10 turns each or in total) on a substrate or carrier material (not illustrated). Its geometry and number of turns may be chosen to provide the necessary inductance which, in combination with its effective capacitance ora separate capacitor, forms a member of the LC circuit of the booster antenna arrangement 6.

[0067] In some illustrative examples herein, the multiple inductive coils of the second antenna arrangement 6b may each consist of multiple printed windings on the substrate (not illustrated) or carrier material (not illustrated) or card body (not illustrated) of a smart card (not illustrated). In illustrative examples herein, the second antenna arrangement 6b may have antenna coils with at most 50 turns or at most 40 turns or at most 20 turns, for example, 2 to 20 turns or 2 to 15 turns or 2 to 20 turns or 2 to 5 turns for each antenna coil. Its geometry and number of turns may be chosen to provide the necessary inductance which, in combination with its effective capacitance or a separate capacitor, forms a member of the LC circuit of the booster antenna arrangement 6.

[0068] The matching circuit 6c may comprise optional capacitance elements (not illustrated), such as one or more ceramic capacitors (not illustrated). These optional capacitance elements (not illustrated) may be connected in parallel with at least one of the first and second antenna arrangements 6a and 6b. For example, optional one or more capacitance elements (not illustrated) may have a value selected so that the booster antenna arrangement 6 is precisely tuned to resonate at the desired operating frequency in a range from about 13 MHz to about 17 MHz, such as in a range from 13.56 MHz to about 17 MHz, e.g., at 13.56 MHz. The matching circuit 6c may further comprise additional passive components, such as small resistors (not illustrated), which may be included to optimize the Q-factor and ensure proper impedance matching between the booster antenna arrangement 6 and the RFID tag 4.

[0069] In some illustrative embodiments, the booster antenna arrangement 6 may be implemented as a block body or thin sticker or flexible film that can be arranged close to a product including one or more RFID target tags 4. For examples booster antenna arrangement 6 may be attached to the back of a smart card (not illustrated) or some other arbitrary product body (not illustrated) with

[0070] 25.3.2025integrated RFID target tag 4. Accordingly, the booster antenna arrangement 6 may act as an external booster antenna configured for amplifying the electromagnetic field from the reader 2 in the RFID system 1, improving both the range and the reliability of the contactless communication without altering the internal structure of the RFID tag 4.

[0071] With ongoing reference to Fig. 1, a function of the booster antenna arrangement 6 in the RFID system 1 will be described. During operation of the RFID reader 2 in the RFID system 1, the booster antenna arrangement 6 increases the reading range of the RFID tag 4. In case of the RFID tag 4 representing a small RFID tag 4, e.g., a small high-frequency (HF) RFID transponder, the booster antenna arrangement 6 may act for enhancing the coupling between the RFID reader 2 and the RFID tag 4. This method is especially useful when dealing with small RFID tags 4 that have limited antenna size and power harvesting capability.

[0072] The term “small” may be understood as indicating that the second antenna arrangement 6b may be small relative to the first antenna arrangement 6a in that a maximum dimension of antenna coils (not illustrated) of the second antenna arrangement 6b (that is a maximum dimension of the dimensions of antenna coils (not illustrated) of the second antenna arrangement 6b in a plane perpendicular to the illustrated paper plane in Fig. 1) is smaller than a smallest dimension of the first antenna arrangement 6a. Herein, dimensions of the first and second antenna arrangements 6a, 6b may be considered as dimensions measured along two perpendicular directions in a plane defined by a virtual plane spanned or approximated such that the antenna arrangement is at least partially routed in the virtual plane to a best degree of approximation, the virtual plane being substantially perpendicular to the paper plane of the illustration in Fig. 1. The dimensions may be related to a dedicated coordinate system associated with at least one or each of the first antenna arrangement 6a and antenna coils (not illustrated) of the second antenna arrangement 6b. For example, a ratio of the maximum dimension to the smallest dimension may be at least 1.5 or at least 2 or at least 3 or at least 4 or at least 8 or at least 10. In some special illustrative examples, the ratio may be in a range from about 2 to about 10, such as in a range from about 2 to about 8 or from a about 2 to about 5 or in a range from about 2 to about 4. In general, any intersection of two or more of these closed intervals and / or semi-closed intervals may be considered.

[0073] The booster antenna arrangement 6 acts as an intermediary between the RFID reader 2 and the small RFID tag 4. The booster antenna arrangement 6 captures and amplifies the electromagnetic field from the RFID reader 2 and then retransmits it to the RFID tag 4, effectively extending the range. Accordingly, the booster antenna arrangement 6 represents an energy relay with passive re-radiation of the electromagnetic field from the RFID reader 2. The first antenna arrangement 6a comprises at least one larger antenna coil relative to the second antenna arrangement 6b, the first

[0074] 25.3.2025antenna arrangement 6a resonating at the same frequency as the RFID reader 2 (e.g., at 13.56 MHz). Accordingly, the booster antenna arrangement 6 captures electromagnetic energy emitted by the RFID reader 2 and re-radiates an electromagnetic field, preferably a stronger field then the field emitted by the RFID reader 2, thereby improving the inductive coupling with the small RFID tag 4. In re-radiating the electromagnetic field, the RFID tag 4 may harvest energy for its operation. In case of the RFID system 1 representing an HF RFID system, the coupling in the HF RFID system relies on near-field magnetic coupling. If an antenna (not illustrated) of the small RFID tag 4 is too small or far from the RFID reader 2, the RFID tag 4 may not receive enough energy in a conventional system, while the booster antenna arrangement 6 allows for increasing the effective field strength at the transponder’s location, ensuring better energy transfer. Accordingly, the booster antenna arrangement 6 acts as an extension of the RFID reader 2 in the RFID system 1 , effectively making the electromagnetic field generated by the RFID reader 2 larger.

[0075] Referring to Fig. 2, an illustrative circuit diagram 100 of a circuitry of a booster antenna arrangement is schematically illustrated, for example as a possible implementation of the booster antenna arrangement 6 described above in the context of Fig. 6. Accordingly, the circuit diagram 100 may be employed in the RFID system 1 of Fig. 1.

[0076] The circuit diagram 100 of the booster antenna arrangement comprises a first antenna arrangement 100a configured for communication with an RFID reader (not illustrated - e.g., the RFID reader 2 in Fig. 1), and a second antenna arrangement 100b configured for communication with at least one RFID tag 200 (e.g., provided by the RFID tag 4 in Fig. 1 ). The first and second antenna arrangements 100a, 100b may be formed in and / or on a card body (not illustrated) of a smart card (not illustrated) or a substrate (not illustrated) or a carrier (not illustrated). For example, the first and second antenna arrangements 100a, 100b may be coplanar in or on a card body (not illustrated) of a smart card (not illustrated) or a substrate (not illustrated) or a carrier (not illustrated). Alternatively, the first antenna arrangement 100a may be at least partially out of plane with respect to the second antenna arrangement 100b.

[0077] For example the first antenna arrangement 100a has one or more windings with a total of about 5 to 10 turns. However, this does not impose any limitation and the first antenna arrangement 110a may have one or more windings with each or in total less than 50 turns or less than 20 turns. For example, the first antenna arrangement may be formed of at least one winding with 5 to 20 turns for each winding or in total.

[0078] For example, the second antenna arrangement 100b comprises three second antenna coils 101, 102, 103 which are electrically interconnected, each of the second antenna coils 101, 102, 103

[0079] 25.3.2025being configured for emitting electromagnetic radiation to and receiving electromagnetic radiation from the RFID tags 200. The second antenna coils 101, 102, 103 are electrically connected in series. Additionally or alternatively, each of the second antenna coils 101, 102, 103 may have a maximum dimension of at most about 15 mm, preferably at most about 10 mm, more preferably at most about 5 mm, such that small RFID tags 200 may be read by the second antenna arrangement 100b. Although Fig. 2 schematically shows three second antenna coils 101, 102, 103, this does not impose any limitation and only two or more than three second antenna coils may be provided, instead. In some illustrative examples, each of the second antenna coils 101, 102, 103 may have less than 50 turns or less than 20 turns each or in total, such as 4-10 turns each or in total).

[0080] With ongoing reference to Fig. 2, the second antenna coils 101 , 102, 103 are electrically connected in series to the first antenna arrangement 100a, the first antenna arrangement 110a comprising two first antenna coils 110 and 120. In some illustrative examples, each of the first antenna coils 110, 120 may have a winding with about 1 to 5 turns or other number of turns as described herein. In some illustrative embodiments, the second antenna coils 101, 102, 103 are electrically connected in series between the first antenna coils 110, 120. Accordingly, the second antenna coils 101, 102, 103 do not have any open end and the second antenna coils 101 and 103 are in direct electrical connection with the first antenna arrangement 100a. That is, the second antenna coil 101 is directly connected to one of the first antenna coils 110, 120, while the second antenna coil 103 is directly connected to the other one of the first antenna coils 110, 120. The second antenna coil 102 is in direct electrical connection with each of the second antenna coils 101 and 103. In some illustrative embodiments and as illustrated in Fig. 2, the second antenna coils 101, 102, 103 are of substantially identical shape and / or size. For examples, each of the second antenna coils 101 , 102, 103 may be of a substantially circular shape. However, this does not impose any limitation and at least one of the second antenna coils 101, 102, 103 may be of an elliptical shape. Additionally or alternatively, at least one of the second antenna coils 101, 102, 103 may be of a polygonal shape, e.g., regular or irregular polygonal shape. Additionally or alternatively, at least two of the antenna coils 101, 102, and 103 may have different winding numbers.

[0081] In some illustrative embodiments, the second antenna coils 101, 102, 103 are wound with identical winding orientation. Alternatively, only two of the second antenna coils 101, 102, 103 are wound with identical winding orientation, e.g., the second antenna coils 102 and 103 are wound with identical winding orientation, while the second antenna coil 101 is wound with an opposite winding orientation.

[0082] 25.3.2025In some illustrative embodiments and as illustrated in Fig. 2, the first and second antenna arrangements 100a, 100b are formed of a single continuous antenna wire. For example, the first antenna arrangement 100a has two open ends 122. For example, one of the first antenna coils 110, 120 may have a single one of the open ends 122, while the other one of the first antenna coils 110, 120 has the other of the open ends 122.

[0083] Herein, the open ends 122 may serve as a capacitance for substantially determining the capacitance of the first antenna arrangement 100a. In some very special illustrative examples with the first antenna arrangement 100a comprising two or more first antenna coils, the antenna coil (120) having two open ends (122) may be regarded as a capacitance determining wire portion routed in a winded wiring track arrangement of plural wire track line portions routed in an intertwined manner, such as a doubly or multifold intertwined spirally shaped routing.

[0084] In some illustrative embodiments and as illustrated in Fig. 2, the second antenna arrangement 100b is completely encircled by the first antenna arrangement 100a.

[0085] In some illustrative embodiments, the second antenna coils 101, 102, 103 may be separated from each other by at least a maximum dimension of each of the second antenna coils 101, 102, 103. Additionally or alternatively, each of the second antenna coils 101, 102, 103 may be separated by at least a maximum dimension of the second antenna coils 101, 102, 103 from the first antenna arrangement 100a.

[0086] The effect of the booster antenna arrangement will become more apparent when referring to Fig.

[0087] 2. Instead of allowing the electromagnetic field of the RFID reader (not illustrated, see RFID reader 2 in Fig. 1 ) to spread out in all directions, the booster antenna arrangement redirects and focuses energy towards the RFID tags 200. This technique may be useful in environments where metal objects or interference may otherwise disrupt the signal.

[0088] Although passive booster antenna arrangements are described above with respect to Fig. 1 and 2, active booster antenna arrangements are not excluded. In a modification of the booster antenna arrangement 6 and the circuit diagram 100, an active booster antenna arrangement may be achieved by further including amplifiers (not illustrated) to actively strengthen the signal emitted by the RFID reader 2 in Fig. 1. Active booster antenna arrangements require an external power source (not illustrated) but offer much greater range enhancement when compared to passive booster antenna arrangements. For example, an amplified antenna array may be employed for boosting signals in high-security access control systems.

[0089] 25.3.2025In alternative embodiments, integrated booster tags may be provided, wherein one or more small RFID tags may be embedded within a larger booster structure, which acts as an extended antenna. For example, contactless payment stickers may be used with a booster antenna to work with small embedded chips.

[0090] Illustrative booster antenna arrangements (such as arrangement 6 in Fig. 1 and circuit diagram 100 in Fig. 2) in an RFID system (such as RFID system 1 in Fig. 1) represent antenna circuits designed to enhance the electromagnetic coupling between a contactless RFID chip and an RFID reader as described in greater detail below. For example, the RFID system 1 of Fig. 1 may include at least one smart card.

[0091] In case of a passive booster antenna arrangement, the contactless RFID chip (c.f. tag 4 in Fig. 1 and each of tags 200 in Fig. 2) draws its energy via induction from the RFID reader’s electromagnetic field. By employing the booster antenna arrangement, the field of the RFID reader (such as RFID reader 2 in Fig. 1) is selectively amplified, enabling the RFID chip (c.f. tag 4 in Fig. 1 and each of tags 200 in Fig. 2) to be reliably powered and to communicate even at greater distances or in challenging environments with the RFID reader (such as RFID reader 2 in Fig. 1 ).

[0092] In HF applications, RFID readers (such as RFID reader 2 in Fig. 1) of HF type typically operate in the 13.56 MHz range. An HF booster antenna arrangement (such arrangement 6 in Fig. 1 and circuit 100 in Fig. 1) is tuned to resonate optimally at this frequency, thereby improving energy transfer between the RFID reader (such as RFID reader 2 in Fig. 1) and the RFID chip (such as tag 4 in Fig. 1 and each of tags 200 in Fig. 2) exposed to the RFID reader (such as RFID reader 2 in Fig. 1). However, this does not impose any limitation and LF or UHF applications with appropriate resonance frequency may be implemented instead.

[0093] Independent of the frequency range to be applied by the RFID reader (such as RFID reader 2 in Fig. 1), booster antenna arrangements (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2) may be implemented as external add-on components (e.g., printed circuit traces or coils) or integrated directly into the design of the RFID chip (such as tag 4 in Fig. 1 and each of tags 200 in Fig. 2), e.g., into a smart card into which the RFID chip (such as tag 4 in Fig. 1 and each of tags 200 in Fig. 2) is integrated.

[0094] As indicated in the background section above, increasing the reading range of small high-frequency RFID tags (such as HF RFID tags operating at 13.56 MHz, for example) can be challenging due to power limitations, antenna size, and environmental factors.

[0095] 25.3.2025The booster antenna arrangement in accordance with various illustrative embodiments account for at least one of the following strategies to enhance the reading range of a target RFID chip to be read by an RFID reader (such as RFID reader 2 in Fig. 1 ).

[0096] As the efficiency of RFID tags (such as tag 4 in Fig. 1 and tag 200 in Fig. 2) is largely dependent on their antenna design. Using a booster antenna with a larger antenna (within size constraints) and / or tuning the booster antenna to the correct impedance (such as 50Q in case of HF applications) can maximize signal reception at the RFID reader (such as RFID reader 2 in Fig. 1 ) and the target RFID chip (such as tag 4 in Fig. 1 and each of tags 200 in Fig. 2).

[0097] Increasing the number of turns in a coil of the booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2) enhances power harvesting because more turns in a coil communicating with the target RFID chip (such as tag 4 in Fig. 1 and each of tags 200 in Fig. 2) improves inductance and coupling with the reader’s field, however, the number of terms being constrained by considerations imposed by scalability in case of small RFID tags (such as tag 4 in Fig. 1 and each of tags 200 in Fig. 2).

[0098] Using high-quality and low-loss materials, such as substrates with lower losses (e.g., high-quality PCB materials instead of regular plastics) improves signal efficiency but also represents a cost factor.

[0099] In any of the above cases, tuning of the resonance of the booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2) to match the resonance of the RFID reader (such as RFID reader 2 in Fig. 1). It can be ensured that the booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2) resonates precisely at the desired resonance frequency, e.g., at 13.56 MHz, by adjusting capacitance and inductance of the booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2).

[0100] Another way of increasing the effective range in the various embodiments of the present application is enhancing the magnetic field generated by reader (such as RFID reader 2 in Fig. 1) and establishing a coupling factor of nearly one among reader (such as RFID reader 2 in Fig. 1 ) and booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2) for increasing the effective range of the reader (such as RFID reader 2 in Fig. 1). Herein, the booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2) is equipped with an antenna arrangement (such as first antenna arrangement 6a in Fig. 1 and 100a in Fig. 2) configured for directly coupling with the antenna (not illustrated) of the reader (such as RFID reader 2 in Fig. 1 ), wherein this antenna arrangement (such as first antenna arrangement 6a in Fig. 1 and 100a in Fig. 2) has an increased antenna size comparable to the antenna size of the reader (such

[0101] 25.3.2025as RFID reader 2 in Fig. 1 ). A large antenna arrangement (such as first antenna arrangement 6a in Fig. 1 and 100a in Fig. 2) at the primary side coupling the booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2) directly with the reader (such as RFID reader 2 in Fig. 1) improves magnetic coupling between reader (such as RFID reader 2 in Fig. 1) and booster antenna arrangement (such as arrangement 6 in Fig. 1 and circuit 100 in Fig. 2).

[0102] A reading operation performed by the RFID system 1 (as shown in Fig. 1 and described with at least the reference to Fig. 1 above) may be optimized by an optimization of the reader 2 and coil geometry for any of the first and second antenna arrangements by proper alignment and proper design of shape such that energy emitted by the reader may be focused more efficiently.

[0103] A coupling efficiency of the booster antenna arrangement 6 may be improved by use of a ferrite backing (not illustrated) for the RFID tag 4. An according ferrite backing may reduce interference from metal surfaces and increase inductive coupling of the booster antenna arrangement 6 to the RFID reader 2 and / or the RFID tag 4.

[0104] In the reading operation, the RFID tag 4 may be oriented with respect to the second antenna arrangement 6b such that the RFID tag 4 is aligned correctly with respect to the electromagnetic field generated by the RFID reader 4 and re-emitted by the booster antenna arrangement 6 to maximize energy transfer. An appropriate alignment is illustrated in Fig. 2 by alignment of tags 200 with respect to second antenna coils 101 and 102.

[0105] By combining multiple strategies as described above, such as optimizing the antenna, increasing reader power, and minimizing interference, the reading range of small RFID tags, such as tag 4 in Fig. 1 and tags 200 in Fig. 2, may be increased.

[0106] Referring to Fig. 2, some illustrative but non-limiting examples are described as follows. The first antenna arrangement 100a may comprise two wiring portions illustrated in Fig. 2 by reference numbers 110 and 120, the two wiring portions determining capacity and inductance of the first antenna arrangement 100a. That is, an outer wiring portion (represented by reference number 120) of the first antenna arrangement 100a may be identified with an antenna wiring portion of the first antenna arrangement 100a having open ends 122 of the antenna wiring, thereby the outer wiring portion determining a capacity of the first antenna arrangement 100a. The outer wiring portion has at least two wiring track line portions routed to extend along each other at least sectionwise in parallel for generating a contribution to the capacitance of the first antenna arrangement such that the capacitance of the first antenna arrangement is substantially determined by the capacitance of the outer wiring portion, wherein substantially determined indicates that the capacitance of the outer wiring portion is at least 70% or at least 80% or at least 90% or at least 95% of

[0107] 25.3.2025the capacitance of the first antenna arrangement 100a. Furthermore, an inductance of the outer wiring portion may be substantially small when compared to the inductance of the first antenna arrangement 100a, such as smaller than 20% or smaller than 10% or smaller than 5 % of the inductance of the first antenna arrangement 100a. The first antenna arrangement 100a further comprises an inner wiring portion (represented by reference number 110) which is at least partially encircled by the outer wiring portion, the inner wiring portion determining an inductance of the first antenna arrangement 100a. The inner wiring portion has a contribution to the inductance of the first antenna arrangement 100a such that the inductance of the first antenna arrangement 100a is substantially determined by the inductance of the outer wiring portion, wherein substantially determined indicates that the inductance of the outer wiring portion is at least 70% or at least 80% or at least 90% or at least 95% of the inductance of the first antenna arrangement 100a. Furthermore, a capacity of the inner wiring portion may be substantially small when compared to the capacity of the first antenna arrangement 100a, such as smaller than 20% or smaller than 10% or smaller than 5 % of the capacity of the first antenna arrangement 100a. In some illustrative examples herein, each of the wiring portions (110, 120) may have about 1 to 20 turns or alternatively, the outer wiring portion may have less than 1 turn, while the inner wiring portion as about 1 to about 40 turns. Additionally or alternatively, the two or more second antenna coils 101, 102, 103 may be connected electrically in series between the wiring portions of the first antenna arrangement 100a.

[0108] In the description above, the second antenna arrangement is described as being at least partially encircled by the first antenna arrangement. However, this does not impose any limitation and the first antenna arrangement may at most only encircle a subset of antenna coils of the second antenna arrangement, instead. For example, the second antenna arrangement may be located outside with respect to the first antenna arrangement such that no antenna coil of the second antenna arrangement is located with respect to the first antenna arrangement such that the second antenna arrangement is encircled by the first antenna arrangement.

[0109] In summary, the present disclosure allows to increase the reading range of small (HF) tags, such as HF transponders. At the same time, a solution is presented in which several small RFID tags, such as HF transponders, can also be recognized by a single reader.

[0110] This solution is achieved for solving the problem of reading small RFID tags. Particularly, small HF RFID transponders are challenging to read with standard reader antennas. Short range and a need of precise positioning making standard readers unsuitable for NFC-equipped smartphones and costly for applications requiring multiple antennas.

[0111] 25.3.2025In this respect, the present disclosure presents, in various embodiments, a booster antenna arrangement with a larger antenna arrangement (wire embedding or etched) with a coupling factor near 1 to the reader antenna size as a first antenna arrangement, and a second antenna arrangement with two or more smaller antennas connected to the larger antennas for reading two or more small HF tags.

[0112] Advantages of various embodiments result in cheaper booster antenna arrangements, more flexible in shape, handling and dimension. Therefore, the present disclosure provides for RFID systems with very low costs in comparison to standard RFID systems, especially when attempting to solve the problem of reading multiple RFID tags with multiple standard readers.

[0113] Standard readers differ over booster antenna arrangements of various embodiments herein in that the standard readers do not have an additional part in an (HF) reader equipped device that is “splitting” a larger (HF) antenna into multiple smaller ones.

[0114] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

[0115] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, “approximately” and “substantially”, are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and / or interchanged, such ranges are identified and include all the subranges contained therein unless context or language indicates otherwise. “Approximately” or “substantially” as applied to a particular value of a range applies to both values, and unless otherwise dependent on the precision of the instrument measuring the value, may indicate + / - 10% of the stated value(s).

[0116] 25.3.2025

Claims

Claims1. A booster antenna arrangement for an RFID chip arrangement, the booster antenna arrangement comprising:a first antenna arrangement configured for communication with an RFID reader; and a second antenna arrangement configured for communication with at least one RFID tag, wherein the second antenna arrangement comprises two or more second antenna coils which are electrically interconnected, each of the two or more second antenna coils being configured for emitting electromagnetic radiation to and receiving electromagnetic radiation from a dedicated one of the at least one RFID tag.

2. The booster antenna arrangement of claim 1, wherein the two or more second antenna coils are electrically connected in series.

3. The booster antenna arrangement of claim 1 or 2, wherein the two or more second antenna coils are electrically connected in series to the first antenna arrangement.

4. The booster antenna arrangement of one of claims 1 to 3, wherein the first antenna arrangement comprises an outer wiring portion with open ends determining a capacity of the first antenna arrangement and an inner wiring portion at least partially encircled by the outer wiring portion, the inner wiring portion determining an inductance of the first antenna arrangement.

5. The booster antenna arrangement of claim 4, wherein each of the wiring portions has about 1 to 20 turns.

6. The booster antenna arrangement of claim 4 or 5, wherein the two or more second antenna coils are connected electrically in series between the wiring portions of the first antenna arrangement.

7. The booster antenna arrangement of one of claims 1 to 6, wherein the two or more second antenna coils are of substantially identical shape and / or size.

8. The booster antenna arrangement of one of claims 1 to 7, wherein the two or more second antenna coils are wound with identical winding orientation.

9. The booster antenna arrangement of one of claims 1 to 8, wherein the first and second antenna arrangements are formed of windings wound with identical winding orientation.25.3.202510. The booster antenna arrangement of one of claims 1 to 9, wherein the first and second antenna arrangements are formed of a single continuous antenna wire.

11. The booster antenna arrangement of one of claims 1 to 10, wherein the first antenna arrangement has two open ends.

12. The booster antenna arrangement of one of claims 1 to 11 , wherein the first and second antenna arrangements are routed in at least one surface of a card body of a smart card or in a surface of a substrate.

13. The booster antenna arrangement of one of claims 1 to 12, wherein the second antenna arrangement is partially or completely encircled by the first antenna arrangement.

14. The booster antenna arrangement of one of claims 1 to 13, wherein the first antenna arrangement has one or more windings with a total of less than 50 turns.

15. The booster antenna arrangement of one of claims 1 to 14, wherein each of the two or more second antenna coils has a maximum dimension of at most about 15 mm, preferably at most about 10 mm, more preferably at most about 5 mm.

16. The booster antenna arrangement of one of claims 1 to 15, wherein each of the two or more second antenna coils is configured to emit and receive electromagnetic radiation at a resonance frequency in a range from about 13 to 17 MHz.

17. The booster antenna arrangement of one of claims 1 to 16, wherein the two or more second antenna coils are separated from each other by at least a maximum dimension of each of the two more second antenna coils.

18. The booster antenna arrangement of one of claims 1 to 17, wherein each of the two or more second antenna coils are separated by at least a maximum dimension of each of the two more second antenna coils from the first antenna arrangement.

19. A card having a card body, the card further comprising the booster antenna arrangement of one of claims 1 to 18, wherein the booster antenna arrangement is formed in and / or on the card body.

20. An RFID system for reading an RFID chip arrangement, the RFID reader comprising: an RFID reader having a reading antenna arrangement; andthe booster antenna arrangement of one of claims 1 to 18,25.3.2025wherein the reading antenna arrangement is configured for communication with the first antenna arrangement.

21. The RFID system of claim 20, wherein the booster antenna arrangement is spatially displaceable relative to the RFID reader with a separation of at least 20 mm.

22. The RFID system of claim 20 or21 , further comprising at least one RFID chip arrangement with at least one RFID chip.

23. The RFID system of claim 22, wherein the booster antenna arrangement is integrated with the RFID chip arrangement into a common product body, wherein each of the at least one RFID antenna chip arrangement is arrangeable in alignment with respect to a dedicated one of the two or more second antenna coils.

24. The RFID system of claim 22, wherein the booster antenna arrangement and the RFID chip arrangement are integrated in different and separable body elements, wherein each of the at least one RFID antenna chip arrangement is arrangeable in alignment with respect to a dedicated one of the two or more second antenna coils.25.3.2025

Images