Microstripline impedance-matching structure for an RFID circuit

Abstract

In some embodiments, a wireless communication device is disclosed. In some embodiments, the present subject matter provides the wireless communication device including a communication circuit and an antenna structure. In some embodiments, the antenna structure is formed out of an electrically conductive material. In some embodiments, an impedance-matching structure is formed out of the electrically conductive material. In some embodiments, the impedance-matching structure includes one or more microstrip lines adapted to be electrically shunted to match an impedance of the communication circuit. In some embodiments, the impedance-matching structure may be electrically coupled to the antenna structure. In other embodiments the impedance-matching structure may be electro- magnetically coupled to the antenna structure. In some embodiments, the one or more microstrip lines are electrically shunted by soldering at least one microstrip line. In some embodiments, the present subject matter also provides a method for impedance-matching of a wireless communication device.

Description

MICROSTRIPLINE IMPEDANCE-MATCHING STRUCTURE FOR AN RFID CIRCUITTECHNICAL FIELD

[0001] The present subject matter generally relates to wireless communication devices and methods of manufacturing wireless communication devices. In particular, the present subject matter relates to a wireless communication device having an impedancematching structure integrated with an antenna structure. Furthermore, the impedancematching structure includes one or more impedance elements configured to change electromagnetic characteristics of the antenna structure to match an impedance of the antenna structure relative to a communication circuit.BACKGROUND

[0002] Wireless communication devices have become ubiquitous in modern technology, enabling seamless data transmission through radio wave propagation across various frequencies and protocols. These devices rely on sophisticated antenna systems to effectively transmit and receive electromagnetic signals, facilitating communication between different components and external networks. The performance of these wireless systems depends heavily on the precise matching of impedances between various circuit elements, particularly between antennas and their associated integrated circuits.

[0003] In wireless communication systems, achieving optimal energy transfer between components requires careful consideration of impedance characteristics. When impedances are properly matched, maximum power transfer occurs, resulting in enhanced system performance and efficiency. However, maintaining this impedance matching across different operating conditions and manufacturing variations presents ongoing challenges in the design and production of wireless devices.

[0004] Radio frequency identification (RFID) technology represents a significant application within this field, where precise antenna design and impedance matching are particularly relevant for optimal performance. RFID systems operate across various frequency bands and require careful coordination between antenna structures and integrated circuit components to achieve reliable communication with external readers.

[0005] Conventional methods require the antenna design to match the impedance of the RFID chip. However, there are challenges and limitations with conventional methods of antenna manufacturing to achieve a desired impedance match between the RFIDantenna and the RFID chip. Such challenges and limitations may include tolerance fits due to manufacturing errors or defects in antenna design that lead to a lowering of the conjugate match between the antenna and the RFID chip. In another scenario, there may be a change in the specified impedance of a given RFID chip, which possesses a different impedance corresponding to a given RFID antenna. In the aforementioned situations, the RFID antenna would need to be redesigned or restructured to achieve the conjugate match between the RFID antenna and the RFID chip. In such a situation, redesigning the RFID antenna is a timeintensive process that also increases manufacturing costs.

[0006] Manufacturing processes for wireless communication devices often involve multiple steps and various materials, each of which can introduce variations that affect the final impedance characteristics of the system. These variations can result from factors such as material properties, dimensional tolerances, environmental conditions during manufacturing, and component placement accuracy. Such variations can lead to performance degradation and reduced efficiency in wireless communication systems.

[0007] The complexity of modern wireless communication systems has increased the demand for more flexible and adaptable impedance matching solutions. Traditional approaches to impedance matching often involve fixed circuit elements or antenna geometries that cannot be easily modified after manufacturing. This can result in suboptimal performance when operating conditions change or when manufacturing variations exceed acceptable tolerances. It is desirable for there to be a conjugate match between the RFID chip of the wireless communication device and the antenna of the wireless communication device. In such a conjugate match, such as pairs of resistance and reactance of the RFID chip and the RFID antenna, the RFID chip and the RFID antenna have equal resistance and opposite reactance. This conjugate match is usually achieved by selecting an antenna configuration that modifies the impedance of the RFID chip and / or by selecting the chip to provide a desired impedance. It may be appreciated that it would be advantageous to have wireless communication devices with improved performance, features, and versatility.

[0008] Therefore, in light of the foregoing, there is a need to overcome the limitations and challenges related to conventional methods and technology involved in RFID manufacturing.SUMMARY

[0009] The present subject matter relates to a wireless communication device having an impedance-matching structure that matches the impedance of a communication circuit to that of an antenna structure of the wireless communication device. In some embodiments, the present subject matter includes an impedance-matching structure for use with, for example, a Radio Frequency circuit, a wireless communication device, an RFID label, or an RFID tag. In some embodiments, the impedance-matching structure facilitates the matching of the impedance of the antenna structure to that of the RFID chip.

[0010] In some embodiments, the antenna structure and the impedancematching structure may be formed from a conductive material. The device may include an adjustment mechanism configured to selectively modify impedance elements to dynamically adjust an overall impedance of the wireless communication device. The adjustment mechanism may include, for example, conductive bridges selectively applied to connect portions of the impedance elements. The adjustment mechanism may be configured to perform at least one of electrically connecting portions of the impedance elements; electrically disconnecting portions of the impedance elements; altering a physical configuration of the impedance elements; or adjusting electromagnetic coupling between the impedance elements and the antenna structure. The device may further include a control unit configured to determine a target impedance for the wireless communication device, iteratively adjust the impedance elements via the adjustment mechanism, and measure resulting impedance changes until the target impedance is achieved.

[0011] According to one aspect of the present subject matter, a method for impedance-matching of a wireless communication device is provided. The method includes providing an antenna structure integrated with an impedance-matching structure, the impedance-matching structure comprising one or more impedance elements; determining a target impedance for the wireless communication device; iteratively modifying one or more of the impedance elements; and measuring resulting impedance changes until the target impedance is achieved.

[0012] According to another aspect of the present subject matter, an impedancematching structure for wireless communication devices is provided. The impedance-matching structure includes an antenna structure and one or more impedance elements configured to change electromagnetic characteristics of the antenna structure to iteratively adjust theoverall impedance of the wireless communication device until the target impedance is achieved.

[0013] These and other features, aspects, embodiments, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed or disclosed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.BRIEF DESCRIPTION OF DRAWINGS

[0014] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present subject matter, exemplary constructions of the subject matter are shown in the drawings. However, the present subject matter is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.

[0015] Embodiments of the present subject matter will now be described, by way of example only, with reference to the following diagrams wherein:FIG. 1A is a front view of a wireless communication device, in accordance with an embodiment;FIG. IB is a rear view of the wireless communication device, in accordance with an embodiment;FIG. 1C is a side view of the wireless communication device, in accordance with an embodiment;FIG. 2A is a front view of the wireless communication device depicting soldering using soldering material to create bridge conductors, in accordance with an embodiment;FIG. 2B is a rear view of the wireless communication device, in accordance with an embodiment;FIG. 2C is a side view of the wireless communication device, in accordance with an embodiment;FIG. 3 is an illustration of a circuit diagram of a wireless communication device depicting the various components of the wireless communication device, in accordance with an embodiment;FIG. 4A is an illustration of the wireless communication device without any microstrip line, in accordance with an embodiment;FIG. 4B is an illustration of a graph depicting the electromagnetic behavior of the wireless communication device without any microstrip line, in accordance with an embodiment;FIG. 4C is an illustration of a Smith chart depicting the electromagnetic behavior of the wireless communication device without any microstrip line, in accordance with an embodiment;FIG. 5A is an illustration of the wireless communication device, including the impedance-matching structure, in accordance with an embodiment;FIG. 5B is an illustration of the impedance-matching structure, including the one or more microstrip lines, in accordance with an embodiment;FIG. 5C is an illustration of a microstrip line of the impedance-matching structure, in accordance with an embodiment;FIG. 5D is an illustration of a Smith chart depicting the electromagnetic behavior of the Wireless communication device, including the first microstrip line, in accordance with an embodiment;FIG. 5E is an illustration of a Smith chart depicting the electromagnetic behavior of the Wireless communication device, including the second microstrip line and soldering the bridge connector to the first microstrip line, in accordance with an embodiment;FIG. 5F is an illustration of a Smith chart depicting the electromagnetic behavior of the Wireless communication device, including the third microstrip line and soldering the bridge connector to the second microstrip line, in accordance with an embodiment;FIG. 5G is an illustration of a Smith chart depicting the electromagnetic behavior of the Wireless communication device, including the fourth microstrip line and soldering the bridge connector to the third microstrip line, in accordance with an embodiment;FIG. 6A is an illustration of the Wireless communication device, including the slit and the shortening pin, in accordance with an embodiment;FIG. 6B is an illustration of a graph depicting the electromagnetic behavior of the Wireless communication device on varying widths of the slit, in accordance with an embodiment;FIG. 6C is an illustration of a Smith chart depicting the electromagnetic behavior of the Wireless communication device 100 on varying widths of the slit, in accordance with an embodiment; andFIG. 7 is a flow chart of a method for impedance-matching of a wireless communication device, in accordance with an embodiment.

[0016] In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.DETAILED DESCRIPTION

[0017] The following detailed description illustrates various embodiments of the present subject matter and ways in which they can be implemented. Although some modes of carrying out the present subject matter have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present subject matter are also possible. Some embodiments disclosed herein include one or more methods and / or devices for matching the impedance of an antenna structure to a communication circuit.Definitions:

[0018] "Wireless communication device" as used herein refers to an electromagnetic device that includes an antenna structure, such as a radio frequency (RF) antenna, and a communication circuit, such as an integrated chip (an RFID chip). In some embodiments, the wireless communication device may be configured to transmit and receive RF signals in the UHF or HF bands used for RFID applications. The device may incorporate the novel impedance-matching structure described in the present subject matter, allowing for optimized power transfer between the antenna structure and the communication circuit. This optimization may enable improved communication range, reliability, and efficiency comparedto conventional designs. The wireless communication device may be passive, drawing power from incoming RF signals, or active with its own power source, depending on the specific application requirements.

[0019] "Communication circuit" as used herein is circuitry that, together with the antenna, enables a wireless communication device to communicate wirelessly. In the context of RFID technology, the communication circuit is typically an RFID chip responsible for processing and storing data, as well as modulating and demodulating radio frequency signals. The communication circuit interfaces with the antenna structure through the impedancematching structure to transmit and receive data. The impedance characteristics of the communication circuit are a critical consideration in the design of the impedance-matching structure, as they need to be matched with the antenna's impedance for optimal performance.

[0020] "Antenna structure" as used herein refers to a conductive element responsible for transmitting and receiving radio frequency signals. In some embodiments, the antenna structure is formed from an electrically conductive material and is designed to efficiently convert electrical currents into electromagnetic waves and vice versa. The antenna structure is integrally connected to the impedance-matching structure to ensure optimal power transfer between the communication circuit and the antenna. The specific geometry and dimensions of the antenna structure may be tailored to the desired operating frequency and performance characteristics of the wireless communication device.

[0021] "Impedance-matching structure" as used herein refers to elements, components and / or features of an antenna structure or a conductive structure such as, but not limited to, for example, an RFID antenna. In some embodiments, the impedance-matching structure facilitates an alteration of the impedance of the antenna structure to match a desired impedance of the communication circuit. In some embodiments, the impedancematching structure is integrated with the antenna structure and includes one or more impedance elements. These one or more impedance elements are configured to change electromagnetic characteristics of the antenna structure to match its impedance relative to the communication circuit. The impedance-matching structure may include one or more microstrip lines arranged in a specific configuration to allow for adjustable impedance characteristics. In some embodiments, the impedance-matching structure enables fine- tuning of the electrical properties to maximize power transfer and communication efficiency.

[0022] "Impedance elements" as used herein refer to components within the impedance-matching structure that can be modified to change the overall impedance characteristics. These impedance elements may include microstrip lines that can be electrically shunted, Micro-Electro-Mechanical Systems (MEMS) switches, micro inductors, capacitors, or materials with variable electrical properties. The ability to adjust these elements allows for dynamic tuning of the impedance matching, adapting to different operating conditions or compensating for manufacturing variations.

[0023] "Adjustment mechanism" as used herein refers to components, systems, or methods for modifying the impedance elements. In some embodiments, the adjustment mechanism may involve electrically connecting or disconnecting portions of the impedance elements, altering the physical configuration, or adjusting electromagnetic coupling between the elements and the antenna structure. The adjustment mechanism works in conjunction with a control unit to iteratively adjust the impedance elements until a target impedance is achieved, ensuring optimal performance of the wireless communication device.

[0024] "Control unit" as used herein refers to an electronic component or subsystem responsible for managing and executing the impedance matching process. In some embodiments, the control unit may be designed to interface with the adjustment mechanism and other elements of the impedance-matching structure to optimize the wireless communication device's performance. The control unit may include processing capabilities to analyze impedance measurements, determine necessary adjustments, and control the modification of impedance elements. Specifically, the control unit may perform functions such as determining a target impedance for the wireless communication device based on the characteristics of the communication circuit and antenna structure. Furthermore, the control unit may initiate and control the iterative adjustment of impedance elements via the adjustment mechanism. In some embodiments, the control unit may include operations such as measuring or receiving data on resulting impedance changes after each adjustment. In some embodiments, the control unit may include operations such as comparing measured impedance values to the target impedance and deciding on further adjustments if needed. In some embodiments, the control unit may include operations such as monitoring operating conditions of the wireless communication device and triggering automatic re-adjustment of the impedance elements when necessary. The control unit may be implemented as a microcontroller, FPGA, or custom ASIC, depending on the complexity of the impedancematching algorithm and the overall design requirements of the wireless communication device. It may also include memory for storing calibration data

[0025] "Dielectric substrate" as used herein refers to an insulating layer attached to the base of the wireless communication device. In some embodiments, the dielectric substrate provides mechanical support and electrical isolation for the conductive elements of the antenna and impedance-matching structures. The dielectric substrate's properties, such as its permittivity and loss tangent, significantly influence the performance of the wireless communication device. In examples, a thickness and material composition of the dielectric substrate affects the electromagnetic field distribution and coupling between different parts of the antenna structure and the impedance matching structure.

[0026] "Conductive sheet" as used herein refers to a conductive layer attached to the side opposite to the impedance-matching structure of the dielectric substrate, forming a ground plane. This ground plane serves multiple purposes, including acting as a reflector to enhance the directivity of the antenna radiation pattern and influencing the input impedance of the antenna structure. The conductive sheet may be modified (e.g., drilled or slit) to further adjust the impedance characteristics of the device.

[0027] "Shunting pin" as used herein refers to a conductive element that provides a direct electrical connection between the impedance-matching structure and the ground plane. In some embodiments, the shunting pin serves as an additional impedance tuning mechanism, allowing for adjustment of the effective electrical length of the antenna and influencing its resonant frequency and input impedance. The shunting pin provides flexibility in adapting to different operating environments or compensating for production variations.

[0028] "Impedance-matching" outlines the process of adjusting the impedance characteristics of the wireless communication device. This method involves providing an antenna structure integrated with an impedance-matching structure, determining a target impedance, iteratively modifying the impedance elements, and measuring the resulting impedance changes until the target impedance is achieved. The method may also include steps for adapting to changes in operating conditions and fine-tuning the impedance match through various techniques such as soldering, drilling, or slitting.

[0029] These and other features, aspects, embodiments, and advantages of the present subject matter will be better understood with reference to the below-stated description and appended claims. These definitions are provided to introduce a selection ofconcepts in a simplified form. These definitions are not intended to identify key features or essential features or keywords of the claimed or disclosed subject matter, nor are they intended to be used to limit the scope of the claimed subject matter.

[0030] The wireless communication device disclosed in this document is described in detail by way of examples and with reference to the figures. Unless otherwise specified, like numbers in the figures indicate references to the same, similar, or corresponding elements throughout the figures. It will be appreciated that modifications to disclosed and described examples, arrangements, configurations, components, elements, apparatuses, methods, materials, etc., may be made and may be desired for a specific application.

[0031] In the present subject matter, any identification of specific shapes, materials, techniques, arrangements, etc., is either related to a specific example presented or is merely a general description of such a shape, material, technique, arrangement, etc. Identifications of specific details or examples are not intended to be, and should not be, construed as mandatory or limiting unless specifically designated as such. Selected examples of apparatuses and methods are hereinafter disclosed and described in detail with reference made to FIGURES.

[0032] Throughout the present subject matter, the term "Wireless communication device" refers to wireless identification tags such as UHF RFID tags, smart tags, and the like, Super High-Frequency tags, and High-Frequency tags. In various embodiments, the wireless identification tags enable or otherwise supports an efficient, cost effective, and time saving item identification and indication to locate, identify and track a desired item. Furthermore, the wireless identification tags in some embodiments, as used herein, enable the determination of the location of an item, information about the availability or presence of the item, and enable a responsive signal of the selected item or desired item.

[0033] Throughout the present subject matter, impedance-matching refers to establishing a conjugate match between the communication circuit input impedance and the antenna impedance. Notably, a maximum energy is transferred between the communication circuit and the antenna when the communication circuit impedance matches the antenna impedance. In order to establish a conjugate match situation, impedance-matching is achieved by configuring the communication circuit and the antenna structure to have equal resistance and opposite reactance.

[0034] As discussed herein in detail, the present subject matter provides an iterative method to match the impedance of the antenna structure to the communication circuit such as a communication circuit via an impedance-matching structure design of the antenna structure. It may be appreciated that the impedance-matching structure design of the antenna structure is at least partially shunted (electrically) using soldering to match the impedance of the communication circuit. In another instance, on exceeding the impedance of the communication circuit via soldering, a de-soldering or removal of soldering material may be performed to achieve the required impedance of the communication circuit. In some embodiments, the antenna structure as used herein is a patch antenna including a radiating element on the top, a base conductive sheet as a ground plane and a dielectric substrate sandwiched between the radiating element and the ground plane.

[0035] FIG. 1A is a front view of a wireless communication device 100, in accordance with an embodiment. FIG. IB is a rear view of the wireless communication device 100, in accordance with an embodiment. FIG. 1C is a side view of the wireless communication device 100, in accordance with an embodiment. In some embodiments herein, the wireless communication device 100 includes a communication circuit 102 and an antenna structure 104. In some embodiments, the wireless communication device 100 includes an impedancematching structure 106. In some embodiments, the impedance-matching structure 106 is formed out of the antenna structure 104. In some embodiments, the impedance-matching structure 106 includes one or more impedance elements 108. In some embodiments, the wireless communication device 100 may include a dielectric substrate 110 attached to a base of the antenna structure 104. In some embodiments, the wireless communication device 100 may include a conductive sheet 112 attached to an underside of the dielectric substrate 110, forming a ground plane.

[0036] In some embodiments, the antenna structure 104 may include an electrically conductive material such as a metal sheet including a thickness and dimensions such as length and width. In some embodiments, the electrically conductive material may be aluminum or an aluminum sheet. In other embodiments, the electrically conductive material may be copper or copper sheet. As used herein, the antenna structure 104 may be manufactured using die cutting, etching or conductive ink printing. In some embodiments, the antenna structure 110 may include a loop antenna. In some embodiments, the antenna structure 110 may include a dipole antenna. In other embodiments, the antenna structure110 may include a capacitor. In some embodiments, the antenna structure 110 may be coupled to the impedance-matching structure 106. In some embodiments, the impedancematching structure 106 is galvanically coupled to the antenna structure 110. In some embodiments, the antenna structure 110 may be electrically coupled to the impedancematching structure 106. In some embodiments, the antenna structure 110 may be electromagnetically coupled to the impedance-matching structure 106.

[0037] In some embodiments, the communication circuit 102 is coupled to the antenna structure 104. This coupling is a critical aspect of the wireless communication device 100 that directly impacts the efficiency of power transfer and signal transmission between the communication circuit 102 and the antenna structure 104. The communication circuit 102 (RFID chip) is typically physically connected to the antenna structure 104 via conductive traces or pads on the substrate. These connections may be made through soldering, conductive adhesives, or other bonding techniques. The impedance-matching structure 106 acts as a tuning device between the communication circuit 102 and the antenna structure 104. The impedance-matching structure 106 transforms the complex impedance of the communication circuit 102 to match the impedance of the antenna structure 104, maximizing power transfer. In some embodiments, the RF signals generated by the communication circuit 102 travel through the impedance-matching structure 106 before being radiated by the antenna structure 104. Similarly, incoming RF signals captured by the antenna structure 104 pass through the impedance-matching structure 106 before reaching the communication circuit 102 for processing.

[0038] For example, in passive RFID systems, the antenna structure 104 also serves to harvest energy from incoming RF signals. This energy is transferred through the impedance-matching structure 106 to power the communication circuit 102. The adjustable nature of the impedance-matching structure 106 allows for fine-tuning of the coupling between the communication circuit 102 and the antenna structure 104. This can compensate for variations in chip impedance or environmental factors affecting the antenna's characteristics. The coupling is designed to operate efficiently within the intended frequency band of the RFID system, typically in the UHF or HF ranges. The communication circuit 102 design and specifications directly influence the requirements for the impedance-matching structure and overall antenna design. This coupling arrangement ensures efficient operationof the wireless communication device, enabling reliable communication with RFID readers while potentially extending the read range and improving overall system performance.

[0039] In some embodiments, the impedance-matching structure 106 includes one or more impedance elements 108 configured to change electromagnetic characteristics of the antenna structure 104 to match the impedance of the antenna structure 104 relative to the communication circuit 102. The impedance-matching structure 106, incorporating one or more impedance elements 108, represents a key innovation in optimizing the performance of RFID devices. These adjustable elements are specifically designed to modify the electromagnetic characteristics of the antenna structure 104, allowing for precise tuning of the antenna's impedance to match that of the communication circuit 102 (RFID chip). This adaptive capability is crucial because the impedance of both the antenna and the communication circuit 102 may vary due to factors such as manufacturing tolerances, environmental conditions, and proximity to different materials. By enabling dynamic adjustment, the system can maintain optimal power transfer and signal integrity across a wide range of operating conditions.

[0040] The impedance elements 108 may take various forms, including but not limited to variable capacitors, inductors, or resistors implemented through microstrip line configurations. These impedance elements 108 may be adjusted through methods such as electrical shunting, physical reconfiguration, or the use of materials with variable electrical properties. For example, one or microstrip lines of different lengths may be selectively connected or disconnected using bridge conductors, effectively altering the overall impedance characteristics of the matching structure. In some examples, impedance elements 108 may include one or more Micro-Electro-Mechanical Systems switches to open or close the alterable regions and micro inductors or capacitors, to adjust an impedance of the antenna structure 104 relative to the communication circuit 102. Additionally, MEMS switches or varactor diodes might be employed to provide voltage-controlled impedance adjustment, offering a high degree of precision and repeatability in the tuning process.

[0041] In some embodiments, the ability to change the electromagnetic characteristics of the antenna structure 104 through these adjustable elements has far- reaching implications for wireless communication device performance. By achieving a more precise impedance match, the system can maximize the power transfer between the communication circuit and the antenna structure, potentially increasing the read range andreliability of the wireless communication device. Furthermore, this adaptability allows for a single antenna design to be optimized for use with different RFID chips or in varying environmental conditions, reducing the need for multiple specialized antenna designs. This flexibility not only improves the versatility of the wireless communication device but also has the potential to streamline manufacturing processes and reduce costs associated with maintaining inventories of different antenna configurations.

[0042] In some embodiments, one or more impedance elements 108 are provided with materials including a phase-change material configured to be selectively activated to alter electrical properties. In some examples, the phase-change materials (PCMs) are substances that may transition between different physical states, typically between solid and liquid phases, in response to external stimuli such as temperature changes or electrical currents. In the context of impedance elements 108, these materials offer a novel method for altering the electrical properties of the impedance-matching structure. When activated, the PCMs undergo a phase transition, which results in a significant change in their electrical conductivity, permittivity, or other relevant electromagnetic properties. By incorporating phase-change materials into the impedance elements 108, this embodiment provides a method for dynamically altering the electromagnetic characteristics of the antenna structure. This approach enables precise, persistent, and potentially reversible impedance matching, enhancing the overall performance and adaptability of the RFID device across various operating conditions and environments.

[0043] In some embodiments, one or more impedance elements 108 are provided with materials including a transparent conductive material configured to be altered using light exposure. Transparent conductive materials that may be altered by light exposure typically consist of photosensitive compounds or nanostructures embedded in a transparent conductive matrix. Furthermore, the intensity and duration of light exposure can be precisely controlled, allowing for very fine adjustments to the impedance characteristics. The impedance-matching structure 106 may be adjusted post-manufacturing to compensate for variations in chip characteristics or environmental conditions. In some examples, the transparent and light-sensitive nature of these materials may allow for integration of optical data transmission or energy harvesting functions alongside impedance matching. By incorporating transparent conductive materials that can be altered using light exposure, this embodiment provides a sophisticated and flexible method for dynamically adjusting theelectromagnetic characteristics of the antenna structure 104. This approach enables precise, contactless, and potentially reversible impedance matching, enhancing the overall performance and adaptability.

[0044] In some embodiments, one or more impedance elements 108 are provided with materials including a thermal material with varying thermal expansion coefficients configured to be altered under variable temperatures. In some embodiments, the thermal material with varying thermal expansion coefficients may be configured to be altered under variable temperatures. This innovative approach utilizes the temperature-dependent properties of certain materials to achieve dynamic impedance matching. By incorporating thermal materials with varying expansion coefficients, this embodiment offers a sophisticated method for dynamically altering the electromagnetic characteristics of the antenna structure 104 based on temperature. This approach enables adaptive impedance matching that responds to environmental conditions, enhancing the overall performance and reliability of the wireless communication device across diverse operating environments and temperature ranges.

[0045] In some embodiments, wireless communication device 100 also includes an adjustment mechanism configured to selectively modify the impedance elements to dynamically adjust an overall impedance of the wireless communication device. This adjustment mechanism is a sophisticated system that enables real-time optimization of the wireless communication device 100 impedance characteristics, ensuring optimal performance across varying operating conditions. In some examples, the adjustment mechanism may include several components, including an actuation system (such as MEMS switches or varactor diodes), a control unit (like a microcontroller or ASIC), sensing elements (e.g., RF power detectors or VSWR meters), and a feedback loop. These components work in concert to continuously monitor the wireless communication device 100 performance and make precise adjustments to the impedance elements 108 as needed.

[0046] The adjustment mechanism may operate in various modes, including automatic adjustment for continuous optimization, scheduled adjustment at predetermined intervals, on-demand adjustment in response to specific triggers, and a calibration mode for comprehensive tuning. The adjustment mechanism may modify the impedance elements 108 through methods such as electrical switching, capacitance variation, physical reconfiguration of components, or modulation of material properties in advanced designs. This dynamicadjustment capability offers numerous advantages, including adaptability to environmental changes, compensation for component aging, multi-band operation potential, improved power efficiency, enhanced read range and reliability, and the ability to compensate for manufacturing tolerances. By incorporating this adjustment mechanism, the wireless communication device 100 becomes a highly adaptive system capable of maintaining peak performance in diverse and challenging RFID deployment scenarios.

[0047] In some embodiments, the adjustment mechanism may include conductive bridges selectively applied to connect portions of the impedance elements. In some embodiments, the adjustment mechanism may include conductive bridges selectively applied to connect portions of the impedance elements 108. These conductive bridges serve as switchable connections between different sections of the impedance-matching structure, allowing for precise and dynamic tuning of the overall impedance characteristics. The conductive bridges may be implemented using various techniques, such as deposited metal strips, conductive adhesives, or mechanical micro-switches. The conductive bridges may be selectively activated or deactivated through electrical, thermal, or mechanical means, enabling the device to reconfigure the impedance-matching structure 108 on demand. For example, a series of parallel microstrip lines could be designed with multiple potential connection points, and conductive bridges could be applied at specific locations to alter the effective length or coupling between these microstrip lines. This approach offers a high degree of flexibility in impedance matching, as different combinations of bridge connections can create a wide range of impedance values and characteristics.

[0048] In some examples, the selective application of these conductive bridges may be controlled by the device's control unit, which may determine the optimal configuration based on real-time performance measurements or predetermined calibration data. This method of impedance adjustment is particularly advantageous for its simplicity, reliability, and potential for fine-grained control, allowing the wireless communication device to adapt to various environmental conditions or compensate for manufacturing variations without the need for complex active components. According to some embodiments, the one or more impedance elements may include one or more microstrip lines configured to be electrically shunted by soldering, with a soldering material, at least one microstrip line at one or more locations using bridge conductors.

[0049] In some embodiments, the adjustment mechanism may be configured to electrically connect portions of the impedance elements, providing a versatile and efficient method for dynamic impedance matching. This approach utilizes an array of switchable connections, which may be implemented using semiconductor switches (e.g., PIN diodes or FET switches), MEMS devices, or other electronically controllable components. These switches are strategically positioned throughout the impedance-matching structure, allowing for selective electrical connections between different sections of the impedance elements. The wireless communication device 100 may activate these switches in various combinations to create different electrical pathways, effectively altering the overall impedance characteristics of the antenna structure. This method enables rapid and precise adjustments without the need for physical reconfiguration of components. The switching can occur in realtime, responding to changes in the operating environment, variations in the RFID chip's impedance, or specific communication requirements. By electrically connecting different portions of the impedance elements, the device can achieve a wide range of impedance values and characteristics, optimizing performance across various frequencies and conditions. This approach offers advantages in terms of speed, precision, and reliability, making it particularly suitable for adaptive RFID systems that must maintain optimal performance in dynamic environments.

[0050] In some embodiments, the adjustment mechanism may be configured to perform an electrical disconnection of portions of the impedance elements. This capability allows for dynamic reconfiguration of the impedance-matching structure 106 by selectively isolating specific sections of the impedance elements 108. The disconnection process may be achieved through various means, such as semiconductor switches, MEMS devices, desoldering or relay systems, which may break the electrical continuity between different parts of the impedance structure. By disconnecting certain portions, the adjustment mechanism may effectively alter the electrical length, capacitance, or inductance of the impedance elements 108, thereby modifying the overall impedance characteristics of the wireless communication device 100. This method offers precise control over the impedance-matching process, allowing the wireless communication device 100 to adapt to changing environmental conditions, varying RFID chip impedances, or different operational frequencies. The ability to disconnect portions of the impedance elements provides a flexible and reversible means ofimpedance adjustment, enabling the device to maintain optimal performance across a wide range of operating scenarios.

[0051] In some embodiments, the adjustment mechanism may be configured to alter the physical configuration of the impedance elements 108. This approach involves mechanically modifying the geometry or spatial arrangement of the impedance elements 108 to achieve the desired impedance characteristics. The adjustment mechanism may incorporate micro actuators, piezoelectric elements, or shape memory alloys to physically deform or reposition parts of the impedance-matching structure. For example, the mechanism could adjust the spacing between capacitive plates, alter the shape of inductive loops, or change the orientation of certain elements relative to the antenna structure 104. This physical reconfiguration allows for a wide range of impedance adjustments, potentially offering greater tuning range than purely electrical methods. The ability to alter the physical configuration can be particularly beneficial in scenarios where large impedance changes are required or when dealing with high-power applications where electrical switching might be limited. This method of adjustment provides a unique combination of flexibility and robustness, enabling the wireless communication device 100 to adapt its impedance characteristics in response to significant changes in its operating environment or communication requirements.

[0052] In some embodiments, the adjustment mechanism may be configured to perform adjusting electromagnetic coupling between the impedance elements and the antenna structure. This configuration focuses on modifying the interaction between the impedance-matching structure and the antenna structure, rather than directly altering the impedance elements 108. The adjustment mechanism may achieve this by varying the proximity or orientation of coupling elements, altering the properties of the intervening dielectric material, or modifying the current distribution on the antenna structure 104. For instance, the mechanism may adjust the position of a coupling loop relative to the antenna structure 104, vary the permittivity of a dielectric spacer using electric field-responsive materials, or selectively activate parasitic elements that influence the antenna structure 104.

[0053] In some embodiments, the wireless communication device 100 also includes a control unit configured to determine a target impedance for the wireless communication device, iteratively adjust the impedance elements 108 via the adjustment mechanism, and measure resulting impedance changes until the target impedance isachieved. This control unit serves as the intelligent core of the impedance matching structure 106, orchestrating a dynamic and adaptive process to optimize the wireless communication device 100 performance. The control unit may include a microprocessor or applicationspecific integrated circuit (ASIC) with associated memory and input / output interfaces.

[0054] In some embodiments, the control unit may operate based on preprogrammed algorithms, machine learning models, or a combination of both to determine the optimal target impedance for various operating conditions. The process of impedance matching through this control unit typically involves assessing and tuning dynamically. The control unit may analyze the current operating environment, including factors such as temperature, proximity to conductive materials, and the specific RFID chip characteristics. Based on the initial assessment and predefined performance criteria, the control unit calculates or selects a target impedance that would optimize the wireless communication device 100 performance. The control unit activates the adjustment mechanism, sending control signals to modify the impedance elements 108. After each adjustment, the control unit measures the new impedance characteristics. This may involve analyzing reflected power, voltage standing wave ratio (VSWR), or other relevant parameters. The measured impedance is compared to the target impedance. If the match is not sufficiently close, the control unit calculates a new adjustment and repeats steps.

[0055] As the measured impedance approaches the target, the control unit may switch to finer adjustments for precise matching. Once the target impedance is achieved, the control unit may continue to monitor the impedance and make minor adjustments to maintain optimal performance. The iterative nature of this process allows the wireless communication device 100 to adapt to changing conditions in real-time. For example, if the wireless communication device 100 is moved from a free-space environment to proximity with a metal surface, the control unit may detect the change in impedance, determine a new target impedance, and adjust the impedance elements 108 accordingly. By incorporating this intelligent control unit with iterative adjustment capabilities, the wireless communication device 100 becomes a highly adaptive system. It can maintain optimal performance across a wide range of operating conditions, enhancing reliability, efficiency, and overall functionality in diverse RFID applications.

[0056] FIG. 2A is a front view of the wireless communication device 100 depicting soldering using soldering material to create bridge conductors 202, in accordance with anembodiment. FIG. 2B is a rear view of the wireless communication device 100, in accordance with an embodiment. FIG. 2C is a side view of the wireless communication device 100, in accordance with an embodiment. As used herein, the impedance elements 108 may include one or more microstrip lines 108, which may be used interchangeably, without departing from the scope of the present subject matter. As depicted herein, one or more microstrip lines 108 may be electrically shunted by soldering using soldering material to create the bridge conductors 202 to at least one microstrip line 108 at one or more locations 204. Furthermore, the one or more locations 204 for soldering at least one microstrip line 108 is based on a required impedance to match the impedance of the antenna structure 104 to the impedance of the RFID chip. In some embodiments, locating the bridge conductors 202 on one or more microstrip lines 108 is defined by the required impedance to match the impedance of the RFID chip.

[0057] In an embodiment, the soldering material may be the same as the antenna structure 104. In another embodiment, the soldering material may be different from the antenna structure 104. In some embodiments, the impedance-matching structure 106 may include an array of microstrip lines 108 placed equidistantly in a patterned shape (such as, for example, any selection of four microstrip lines are positioned parallel to each other] as demonstrated in FIG. 2A. In some embodiments, the one or more microstrip line 108 are galvanically coupled to the antenna structure 110. In some embodiments, the dielectric substrate 110 and the conductive sheet 112 are drilled to the one or more microstrip line 108 to match the impedance of the RFID chip. As shown in FIG. 2A-C, the one or more microstrip line 108 and the conductive sheet 112 is shunted via a shunting pin 206 to match the impedance of the RFID chip. In some embodiments, the conductive sheet 112 may include a slit 208 at the rear side of the wireless communication device 100. In an example, the slit 208 may include a width of, but not limited to, 0.1 millimeters or in a range of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and up to 1.9 millimeters.

[0058] FIG. 3 is an illustration of a circuit diagram of a wireless communication device 300 depicting the various components of the Wireless communication device 300, in accordance with an embodiment. It may be appreciated that the Wireless communication device 300 is the same as the wireless communication device 100 (as shown in FIG. 1A-C and 2A-C) represented in circuit form. In some embodiments, the wireless communication device 300 may include an RFID chip 302. In some embodiments, the wireless communication device300 may include an electrically conductive material 304 electromagnetically coupled to an impedance-matching structure 306.

[0059] FIG. 4A is an illustration of the wireless communication device 100 without any microstrip line, in accordance with an embodiment. FIG. 4A depicts the wireless communication device 100 in its basic configuration, without any microstrip lines for impedance matching. This representation showcases the fundamental antenna structure and provides a baseline for understanding the device's electromagnetic behavior before the implementation of impedance matching techniques.

[0060] FIG. 4B is an illustration of a graph 400 depicting the electromagnetic behavior of the wireless communication device 100 without any microstrip line, in accordance with an embodiment. As shown in FIG. 4B, the graph 400 shows the scattering parameters (magnitude), including the return loss at f = 5.7884 GHz and an amount of around -7.5 dB. FIG. 4B presents a graph 400 that visualizes the electromagnetic behavior of the wireless communication device 100 in its unmodified state. The graph displays the scattering parameters, specifically focusing on the magnitude of the return loss. A notable feature of this graph is the return loss measurement at a frequency of 5.7884 GHz, which shows a value of approximately -7.5 dB. This relatively high return loss indicates that a significant portion of the input power is being reflected back to the source rather than being radiated by the antenna, suggesting suboptimal impedance matching at this frequency.

[0061] FIG. 4C provides a Smith chart 402 representation of the device's electromagnetic behavior, offering an impedance view of the scattering parameters. The Smith chart is a powerful tool for visualizing complex impedances and is particularly useful for antenna design and impedance matching. A key point highlighted in this chart is the marker at the desired operational frequency of 5.9 GHz (labeled as marker 1). This frequency represents the intended design target for the antenna's optimal performance. However, the chart reveals that the actual operational frequency of the device differs from this desired frequency of 5.9 GHz. This discrepancy between the designed and actual operational frequencies further underscores the need for impedance matching to optimize the wireless communication device 100 performance. The Smith chart provides valuable insights into the nature of the impedance mismatch, showing how far the actual impedance is from the ideal center point of the chart, which represents a perfect match to the characteristic impedance of the system (typically 50 ohms for many RF applications).

[0062] FIG. 5A is an illustration of the wireless communication device 100 including the impedance-matching structure 106, in accordance with an embodiment. In some embodiments, the impedance-matching structure 106 may be easily implemented and reconfigurable for different amounts of desired return loss. In some embodiments, as per the requirement of the impedance of the communication circuit 102, the impedance-matching structure 106 may include at least one microstrip line 108 and electrically shunted by soldering using soldering material to create at least one bridge conductor 202 at one location 204.

[0063] FIG. 5B is an illustration of the impedance-matching structure 106, including one or more microstrip lines 108A-D, in accordance with an embodiment. In some embodiments, one or more microstrip lines 108A-D are located and are electrically shunted by soldering, with soldering material, to create one or more bridge conductors 202A-D at one or more locations 204A-D. These bridge conductors are positioned at carefully selected locations 204A-D, each chosen to contribute to the desired impedance-matching effect. The process of soldering these bridge conductors provides a reliable and permanent method of creating electrical connections between different sections of the microstrip lines. This configuration allows for a high degree of customization in the impedance-matching process, as the specific placement and number of bridge conductors can significantly influence the electrical characteristics of the structure. By selectively connecting different portions of the microstrip lines, the impedance-matching structure 106 can be tailored to address a wide range of impedance mismatches, enabling the wireless communication device to achieve optimal performance across various operating conditions and frequencies.

[0064] FIG. 5C is an illustration of microstrip line 108A of the impedance-matching structure 106, in accordance with an embodiment. In some embodiments, one or more microstrip lines 108A-D may be etched on the dielectric substrate, and the bridge connectors 202A-D may be soldered to achieve the desired impedance to match the impedance of the RFID chip and return loss. In some embodiments, the bridge connector 202A may be located at one of the locations 504A-E over a length of the bridge connector 202A. Furthermore, the soldering process is iterated to determine the location of the bridge connector 202A at one of the locations at 504A-E. For example, the one or more locations 504A-E may be divided into five locations such as 504A may be at an initial length (X=0) of the bridge connector 202A, 504B may be at one-fourth of the length of the bridge connector 202A, 504C may be at halfof the length of the bridge connector 202A, 504D may be at three-fourth of the length of the bridge connector 202A and 504E may be at full length of the bridge connector 202A. In such an instance, varying lengths of locations 504A to 504E may provide an impedance with a resistance of between 1.30 to 1.70 and inductive reactance of between 1860 to 2070. Similarly, in the microstrip lines 108B, 108C and 108E, the positioning of the bridge connectors 202B, 202C and 202D may increase the input resistance, and inductive reactance up to 3.50, and 2650, respectively. Based on the impedance of the Communication circuit 102, the one or locations of the bridge connectors 202B, 202C and 202D.

[0065] FIG. 5D is an illustration of a Smith chart 506 depicting the electromagnetic behavior of the wireless communication device 100, including the first microstrip line 108A, in accordance with an embodiment. As depicted in FIG. 5D, variation of the impedance of the wireless communication device 100 on varying a location of the bridge connector 202A over the length first microstrip line 508A of the from 504A to 504E. FIG.

[0066] 5E is an illustration of a Smith chart 508 depicting the electromagnetic behavior of the wireless communication device 100, including the second microstrip line 508B with the bridge connector 202B is created by soldering the first microstrip line 108A, in accordance with an embodiment. As depicted in FIG. 5D, variation of the impedance of the wireless communication device 100 on varying a location of the bridge connector 202B over the length of the second microstrip line 108B from 504A to 504E.

[0067] FIG. 5F is an illustration of a Smith chart 510 depicting the electromagnetic behavior of the wireless communication device 100, which includes the third microstrip line 108C with the bridge connector 202C is created by soldering the second microstrip line 508B, in accordance with an embodiment. In addition, the Smith chart 510 shows the variation of the impedance of the wireless communication device 100 that results from varying a location of the bridge connector 202C over the length of the third microstrip line 108C from 504A to 504E.

[0068] FIG. 5G is an illustration of a Smith chart 512 depicting the electromagnetic behavior of the wireless communication device 100, including the fourth microstrip line 108D and the bridge connector 202D is created by soldering the third microstrip line 508C, in accordance with an embodiment. In addition, the Smith chart 510 shows the variation of the impedance of the wireless communication device 100 that results from varying a location ofthe bridge connector 202D over the length of the fourth microstrip line 108D from 504A to 504E.

[0069] FIG. 6A is an illustration of the wireless communication device 100, including the slit 208 and the shortening pin 206, in accordance with an embodiment. In an example, the slit 208 may control and enhance an amount of a total reactive inductance of the impedance-matching structure, and obtain a required return loss. Notably, the slit 208 facilitates a higher degree of freedom for designing the impedance-matching structure at the desired frequency. In other words, the presence of the capacitive susceptance may allow increasing the amount of impedance, including both the resistance and inductive reactance to the impedance-matching structure (when converted in series form) and fine-tuning the frequency in which the maximum impedance-matching is required.

[0070] FIG. 6B is an illustration of a graph 602 depicting the electromagnetic behavior of the wireless communication device 100 on varying the width of the slit 208, in accordance with an embodiment. In some embodiments, the width of the slit 208 taken as d at 0.45 millimeters and 0.65 millimeters. As shown in the FIG. 6B, the graph 602 shows the scattering parameters (magnitude), including the return loss at f = 5.7884 GHz and f = 5.8 GHz, being approximately -20 dB and -30dB, respectively. The study examines two specific slit widths: 0.45 millimeters and 0.65 millimeters, demonstrating how small changes in slit 208 geometry can significantly impact device performance. The graph displays scattering parameters, focusing on return loss magnitude at two key frequencies. At 5.7884 GHz, the return loss is approximately -20 dB, while at 5.8 GHz, it improves to about -30 dB. These values represent a substantial enhancement in impedance matching compared to the unmodified device, with the -30 dB return loss at 5.8 GHz indicating that only about 0.1% of input power is being reflected. This marked improvement in return loss across a narrow frequency range highlights the sensitivity of the device's performance to slit width adjustments and underscores the effectiveness of the slit 208 as an impedance matching element. The graph effectively demonstrates how precise control of the slit 208 width can be leveraged to optimize the wireless communication device's electromagnetic behavior, particularly in applications requiring specific frequency responses.

[0071] FIG. 6C is an illustration of a Smith chart 604 depicting the electromagnetic behavior of the wireless communication device 100 on varying widths of the slit 208, in accordance with an embodiment. This chart provides a comprehensive view of the device'simpedance characteristics across a range of frequencies, with specific focus on how changes in the slit width affect these properties. The Smith chart displays complex impedance data in a polar format, allowing for simultaneous visualization of both resistive and reactive components. As the slit 208 width is adjusted, the impedance traces on the chart shift, illustrating how this parameter influences the device's overall impedance matching. The chart likely shows multiple curves or markers corresponding to different slit widths, enabling direct comparison of their effects. Key points on the chart may highlight specific frequencies of interest, such as the desired operational frequency and points of optimal matching. By presenting this data on a Smith chart provides an assessment how varying the slit width impacts critical factors such as resonance, bandwidth, and the proximity to ideal matching conditions (typically the center of the chart). This representation is particularly valuable for fine-tuning the impedance matching of the wireless communication device 100, provides intuitive insights into complex impedance behaviors.

[0072] FIG. 7 is an illustration of a flow chart of a method 700 for impedancematching of a wireless communication device, in accordance with an embodiment.

[0073] At step 702, an antenna structure 104 is integrated with an impedancematching structure 106. In some embodiments, the antenna structure is formed out of an electrically conductive material. In some embodiments, the electrically conductive material is selected for impedance-matching with an RFID chip and may be, for example, aluminum or an aluminum sheet. In other embodiments, the electrically conductive material may be copper or a copper sheet. As used herein, the electrically conductive material may be manufactured using die cutting, etching or conductive ink printing. In some embodiments, the electrically conductive material may include the antenna structure within the dimension of the electrically conductive material.

[0074] In some embodiments, the antenna structure 104 may be integrated with an impedance-matching structure 106, creating a unified and efficient electromagnetic system. This integration allows for seamless interaction between the radiating elements of the antenna and the impedance-matching components, enabling precise tuning of the device's overall impedance characteristics. The impedance-matching structure 106 may include one or more impedance elements 108 such as microstrip lines, stubs, or other reactive components strategically positioned within or adjacent to the antenna structure 104. This close integration facilitates the manipulation of current distributions and field patterns,allowing for optimized power transfer between the antenna structure 104 and the connected communication circuit.

[0075] At step 704, a target impedance for the wireless communication device 100 is determined. This target impedance represents the ideal electrical characteristics that the wireless communication device 100 exhibits to maximize power transfer, minimize signal reflection, and ensure efficient operation. The target impedance may be calculated based on various factors, including the impedance of the RFID chip, the desired operational frequency, and the specific requirements of the application. It may consider environmental conditions, nearby materials, and the expected range of operating scenarios. The process of determining the target impedance may involve theoretical calculations, computer simulations, or empirical measurements. Once established, this target impedance serves as a reference point for the adjustment and tuning of the impedance-matching structure, guiding the iterative process of impedance matching to achieve optimal device performance across intended operational parameters of the wireless communication device 100.

[0076] At step 706, one or more of the impedance elements 108 are iteratively modified. The iterative modification of one or more impedance elements 108 is a dynamic process aimed at fine-tuning the wireless communication device 100 impedance characteristics. This process involves systematically altering the properties of the impedance elements 108, such as microstrip lines, capacitive stubs, or inductive loops, in a step-by-step manner. Each iteration may involve changing the length, width, position, or electrical connectivity of these elements. After each modification, the wireless communication device 100 impedance is measured and compared to the target impedance. Based on this comparison, further adjustments are made, with each subsequent iteration bringing the wireless communication device 100 impedance closer to the desired value. This iterative approach allows for precise control and optimization, accounting for complex interactions between different elements of the impedance-matching structure. By employing this iterative method, the wireless communication device 100 may achieve impedance matching that is suitable for its intended use, enhancing overall performance.

[0077] At step 708, resulting impedance changes are measured until the target impedance is achieved. After each iterative modification of the impedance elements 108, the wireless communication device 100 new impedance characteristics are carefully measured using techniques such as network analysis, reflection coefficient measurements, or directimpedance measurements. These measurements provide quantitative data on how the recent adjustments have affected the wireless communication device 100 overall impedance. The measured values are then compared to the predetermined target impedance, allowing for an assessment of how close the device is to achieving desired performance. This continuous measurement and comparison process guide further adjustments, with each cycle bringing the wireless communication device 100 impedance closer to the target. The process continues until the measured impedance falls within an acceptable range of the target impedance, typically defined by specific tolerance limits. This methodical approach ensures that the wireless communication device 100 reaches and maintains the desired impedance.

[0078] The steps 702 to 708 are only illustrative, and other alternatives can also be provided where one or more steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein.

[0079] In some embodiments, the method 700 also includes modifying the impedance elements by electrically connecting portions of the impedance elements; electrically disconnecting portions of the impedance elements; altering a physical configuration of the impedance elements; or adjusting electromagnetic coupling between the impedance elements and the antenna structure.

[0080] In some embodiments, the method 700 also includes detecting a change in the wireless communication device's operating conditions and automatically re-adjusting the impedance elements to maintain optimal impedance matching. In some embodiments, the target impedance is determined based on characteristics of a communication circuit coupled to the antenna.

[0081] In some embodiments, the method 700 also includes electrically shunting by soldering the one or more impedance elements comprising one or more microstrip lines, with a soldering material, at one or more locations of the one or more microstrip lines using bridge conductors. In some embodiments, the one or more locations are based on a required impedance to match the impedance of the electrically conductive material to the impedance of the antenna structure relative to the communication circuit.

[0082] In some embodiments, the method 700 also includes defining one or more locations for soldering the impedance elements. In some embodiments, the method 700 also includes determining an impedance of the antenna structure relative to the communicationcircuit. In some embodiments, the method 700 also includes soldering a first impedance element to the antenna structure at a first location to match the impedance of the antenna structure relative to the communication circuit. In some embodiments, the method 700 also includes measuring the impedance of the electrically conductive material with the bridge conductor soldered to the first impedance element to the antenna structure at one location. In some embodiments, the method 700 also includes soldering the first impedance element at a second location in case the impedance of the antenna structure relative to the communication circuit does not match. In some embodiments, the method 700 also includes soldering a second impedance element to the first impedance element. In some embodiments, the method 700 also includes soldering one or more further impedance elements until the impedance of the antenna structure relative to the communication circuit is matched.

[0083] In some embodiments, the method 700 also includes removing the soldering material on exceeding a required impedance to match the impedance of the antenna structure relative to the communication circuit. In some embodiments, the method 700 also includes attaching a dielectric substrate to a base of the antenna structure. In some embodiments, the method 700 also includes attaching a conductive sheet attached to a side opposite to the impedance-matching structure of the dielectric substrate, thereby forming a ground plane.

[0084] In some embodiments, the method 700 also includes drilling the dielectric substrate and the conductive sheet to one or more impedance elements to match the impedance of the RFID chip. In some embodiments, one or more impedance elements and the conductive sheet are shunted via a shunting pin to match the impedance of the antenna structure relative to the communication circuit. In some embodiments, the method 700 also includes cutting a slit from the conductive sheet to increase the impedance of the antenna structure to match the impedance of the communication circuit.

[0085] Modifications to embodiments of the present subject matter described in the foregoing are possible without departing from the scope of the present subject matter as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "have", "is" used to describe and claim the present subject matter are intended to be construed in a non-exclusive manner, namely allowing for items, componentsor elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

Claims

CLAIMSWhat is claimed is:

1. A wireless communication device comprising: a communication circuit; an antenna structure; and an impedance-matching structure integrated with the antenna structure, the impedance-matching structure comprising one or more impedance elements configured to change electromagnetic characteristics of the antenna structure to match an impedance of the antenna structure relative to the communication circuit.

2. The device of claim 1, wherein the antenna structure and the impedancematching structure are formed from a conductive material.

3. The device of claim 1, further comprising an adjustment mechanism configured to selectively modify the impedance elements to dynamically adjust an overall impedance of the wireless communication device.

4. The device of claim 3, wherein the adjustment mechanism comprises conductive bridges selectively applied to connect portions of the impedance elements.

5. The device of claim 4, wherein the adjustment mechanism is configured to perform at least one of: electrically connecting portions of the impedance elements; electrically disconnecting portions of the impedance elements; altering a physical configuration of the impedance elements; or adjusting electromagnetic coupling between the impedance elements and the antenna structure.

6. The device of claim 5, further comprising a control unit configured to: determine a target impedance for the wireless communication device; iteratively adjust the impedance elements via the adjustment mechanism; and measure resulting impedance changes until the target impedance is achieved.

7. The device of claim 6, wherein the one or more impedance elements comprises one or more microstrip lines configured to be electrically shunted by soldering, with a soldering material, at least one microstrip line at one or more locations using bridge conductors.

8. The device of claim 7 , further comprising a dielectric substrate attached to a base of the wireless communication device.

9. The device of claim 8, further comprising a conductive sheet attached to a side opposite to the impedance-matching structure of the dielectric substrate, thereby forming a ground plane.

10. The device of claim 9, wherein the dielectric substrate and the conductive sheet are drilled to the one or more adjustable elements to match the impedance of the antenna structure relative to the communication circuit.

11. The device of claim 10, wherein the one or more adjustable elements and the conductive sheet are shunted via a shunting pin to match the impedance of the antenna structure relative to the communication circuit.

12. The device of claim 1, wherein the communication circuit is an RFID chip.

13. The device of claim 1, further comprising one or more Micro-Electro- Mechanical Systems switch switches to open or close the one or more adjustable elements and micro inductors or capacitors, to adjust an impedance of the antenna structure relative to the communication circuit.

14. The device of claim 1, wherein the one or more impedance elements are provided with materials comprising at least one of: a phase-change material configured to be selectively activated to alter electrical properties; a transparent conductive material configured to be altered using light exposure; and a thermal material with varying thermal expansion coefficients configured to be altered under variable temperatures.

15. A method for impedance-matching of a wireless communication device, comprising: providing an antenna structure integrated with an impedance-matching structure, the impedance-matching structure comprising one or more impedance elements; determining a target impedance for the wireless communication device; iteratively modifying one or more of the impedance elements; and measuring resulting impedance changes until the target impedance is achieved.

16. The method of claim 15, wherein modifying the impedance elements comprises at least one of:electrically connecting portions of the impedance elements; electrically disconnecting portions of the impedance elements; altering a physical configuration of the impedance elements; or adjusting electromagnetic coupling between the impedance elements and the antenna structure.

17. The method of claim 15, further comprising detecting a change in operating conditions of the wireless communication device; and automatically re-adjusting the impedance elements to maintain optimal impedance matching.

18. The method of claim 15, wherein the target impedance is determined based on characteristics of a communication circuit coupled to the antenna structure.

19. The method of claim 15, further comprising electrically shunting by soldering the one or more impedance elements comprising one or more microstrip lines, with a soldering material, at one or more locations of the one or more microstrip lines using bridge conductors.

20. The method of claim 19, wherein the one or more locations are based on a required impedance to match the impedance of the electrically conductive material to the impedance of the antenna structure relative to the communication circuit.

21. The method of claim 19, further comprising defining the one or more locations for soldering the impedance elements, the steps include: determining an impedance of the antenna structure relative to the communication circuit; soldering a first impedance element to the antenna structure at a first location to match the impedance of the antenna structure relative to the communication circuit; measuring the impedance of the electrically conductive material with the bridge conductor soldered the first impedance element to the antenna structure at one location; soldering the first impedance element at a second location in case the impedance of the antenna structure relative to the communication circuit not matched; soldering a second impedance element to the first impedance element; and soldering one or more further impedance elements until the impedance of the antenna structure relative to the communication circuit is matched.

22. The method of claim 19, further comprising removing the soldering material on exceeding a required impedance to match the impedance of the electrically conductivematerial to match the impedance of the antenna structure relative to the communication circuit.

23. The method of claim 15, further comprising attaching a dielectric substrate to a base of the antenna structure.

24. The method of claim 23, further comprising attaching a conductive sheet attached to a side opposite to the impedance-matching structure of the dielectric substrate, thereby forming a ground plane.

25. The method of claim 24, further comprising drilling the dielectric substrate and the conductive sheet to the one or more impedance elements to match the impedance of the RFID chip.

26. The method of claim 25, wherein the one or more impedance elements and the conductive sheet are shunted via a shunting pin to match the impedance of the antenna structure relative to the communication circuit.

27. The method of claim 25, further comprising cutting a slit from the conductive sheet to increase the impedance of the antenna structure to match the impedance of the communication circuit.

28. An impedance-matching structure for wireless communication devices, comprising: an antenna structure; and one or more impedance elements configured to change electromagnetic characteristics of the antenna structure to iteratively adjust the overall impedance of the wireless communication device until the target impedance is achieved.

29. The impedance-matching structure of claim 28, wherein the antenna structure and the impedance-matching structure are formed from a conductive material.

30. The impedance-matching structure of claim 28, further comprising a control unit configured to: determine a target impedance for a wireless communication device; selectively modify one or more of the impedance elements; iteratively adjust the overall impedance of the wireless communication device until the target impedance is achieved; monitor operating conditions of the wireless communication device; andautomatically re-adjust the impedance elements in response to detected changes in the operating conditions.

31. The impedance-matching structure of claim 28, wherein the one or more impedance elements comprises one or more microstrip lines configured to be electrically shunted by soldering, with a soldering material, at least one microstrip line at one or more locations using bridge conductors.

32. The impedance-matching structure of claim 31, wherein the one or more locations are based on a required impedance to adjust the overall impedance of the wireless communication device until the target impedance is achieved.

33. The impedance-matching structure of claim 28, further comprising a dielectric substrate attached to a base of the antenna structure.

34. The impedance-matching structure of claim 33, further comprising conductive sheet attached to a side opposite to the impedance-matching structure of the dielectric substrate, thereby forming a ground plane.

35. The impedance-matching structure of claim 34, wherein the dielectric substrate and the conductive sheet are drilled to the one or more adjustable impedance to adjust the overall impedance of the wireless communication device until the target impedance is achieved.

36. The impedance-matching structure of claim 35, wherein the one or more adjustable impedance and the conductive sheet are shunted via a shunting pin to adjust the overall impedance of the wireless communication device until the target impedance is achieved.

37. The impedance-matching structure of claim 28, further comprising one or more Micro-Electro-Mechanical Systems switch switches to open or close the one or more adjustable elements and micro inductors or capacitors, to adjust the overall impedance of the wireless communication device until the target impedance is achieved.

38. The impedance-matching structure of claim 28, wherein the one or more impedance elements are provided with materials comprising at least one of: a phase-change material configured to be selectively activated to alter electrical properties; a transparent conductive material configured to be altered using light exposure; anda thermal material with varying thermal expansion coefficients configured to be altered under variable temperatures.

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