Radio frequency identification (RFID) antenna and communication system

Abstract

A radio frequency identification (RFID) antenna is provided. The RFID antenna includes, but is not limited to, a printed circuit board (PCB). The PCB includes, but is not limited to: a substrate; the present invention relates to a semiconductor device comprising a substrate, an etched metal layer on the substrate, where the etched metal layer comprises: a radiating element positioned on the substrate, the radiating element having a loop structure, where the loop structure comprises two first beveled edges, and the first beveled edges are positioned in opposite corners of the loop structure; and a ground element positioned on the substrate, the ground element having a slotted structure concentric with the loop structure and positioned in an interior region of the loop structure.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate generally to radio frequency identification (RFID) communication systems and, more particularly, in some examples, to RFID antennas for RFID communication systems. Background Art

[0002] Applicants have recognized many technical challenges and difficulties associated with compact RFID reader antenna assemblies. Through hard work, ingenuity and innovation, Applicants have solved the problems associated with compact RFID reader antenna assemblies by developing solutions embodied in the present disclosure, which are described in detail below. Summary of the invention

[0003] Various embodiments described herein relate to components, devices, and systems for monitoring the temperature of internal organs.

[0004] According to various embodiments of the present disclosure, a radio frequency identification (RFID) antenna is provided. The RFID antenna includes but is not limited to a printed circuit board (PCB). The PCB includes but is not limited to: a substrate; an etched metal layer on the substrate, wherein the etched metal layer includes: a radiating element positioned on the substrate, the radiating element having a loop structure, wherein the loop structure includes two first beveled edges, and the two first beveled edges are positioned in opposite corners of the loop structure; and a grounding element positioned on the substrate, the grounding element having a slotted structure, the slotted structure being concentric with the loop structure and positioned in an inner region of the loop structure.

[0005] In some embodiments, the PCB further comprises a metal cavity structure, wherein the metal cavity surrounds the PCB such that electromagnetic wave radiation from the radiating element emits a directional radiation pattern.

[0006] In some embodiments, the metal cavity structure includes a metal back plate and a metal wall plate, wherein the metal back plate is positioned on a side of the substrate away from the etched metal layer, and the metal wall plate is positioned on a sidewall of the PCB.

[0007] In some embodiments, the metal cavity structure further includes a plastic sheet covering the PCB in the metal cavity structure.

[0008] In some embodiments, the substrate is made of flame retardant (FR4) material or Teflon.

[0009] In some embodiments, the grooved structure further includes beveled edges on at least two opposing corners of the grooved structure.

[0010] In some embodiments, each of the two first beveled edges of the loop structure is at 45° relative to an adjacent side of the loop structure.

[0011] In some embodiments, the loop structure further includes two second beveled edges in second two opposing corners of the loop structure.

[0012] In some embodiments, the two first beveled edges of the loop structure have a first width, the two second beveled edges of the loop structure have a second width, and the first width is different from the second width.

[0013] In some embodiments, the slotted structure further includes two first beveled edges on first two opposing corners of the slotted structure and two second beveled edges on second two opposing corners of the slotted structure.

[0014] In some embodiments, each of the two second beveled edges of the loop structure is at 45° relative to an adjacent side of the loop structure.

[0015] In some embodiments, the electromagnetic waves radiated from the radiating element are circularly polarized.

[0016] In some embodiments, each of the two first beveled edges of the loop structure is at 45° relative to an adjacent side of the loop structure.

[0017] According to another embodiment, a radio frequency identification (RFID) communication system is provided. The RFID communication system includes, but is not limited to, an RFID antenna. The RFID antenna includes, but is not limited to, a printed circuit board (PCB). The PCB includes, but is not limited to: a substrate; an etched metal layer on the substrate, wherein the etched metal layer includes: a radiating element positioned on the substrate, the radiating element having a loop structure, wherein the loop structure includes two first beveled edges, and the first two beveled edges are positioned in opposite corners of the loop structure; and a grounding element positioned on the substrate, the grounding element having a slotted structure, the slotted structure being concentric with the loop structure and positioned in an inner region of the loop structure.

[0018] In some embodiments, the RFID communication system further includes a controller communicatively coupled to the radiating element and the ground element, wherein the controller is configured to cause the radiating element to emit or radiate electromagnetic waves into space or to capture incoming electromagnetic waves upon reception.

[0019] According to another embodiment, a radio frequency identification (RFID) antenna is provided. The RFID antenna includes but is not limited to a printed circuit board (PCB), wherein the PCB includes: a substrate; an etched metal layer on the substrate, wherein the etched metal layer includes: a radiating element positioned on the substrate, the radiating element having a loop structure, wherein the loop structure includes four first beveled edges positioned in four corners of the loop structure and four second beveled edges positioned in the four corners of the loop structure; and a grounding element positioned on the substrate, the grounding element having a slotted structure, the slotted structure being concentric with the loop structure and positioned in an inner region of the loop structure, wherein the slotted structure also includes four third beveled edges on the four corners of the slotted structure.

[0020] The above exemplary invention content and other exemplary objects and / or advantages of the present disclosure and the manner of achieving these objects and / or advantages are further explained in the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The description of the exemplary embodiments may be read in conjunction with the accompanying drawings. It will be appreciated that, for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale unless otherwise described. For example, the dimensions of some of the elements may be exaggerated relative to other elements unless otherwise described. Embodiments incorporating the teachings of the present disclosure are shown and described with respect to the drawings presented herein, in which:

[0022] Figure 1 An example diagram illustrating an example RFID antenna according to various embodiments of the present disclosure is shown;

[0023] Figure 2 An example diagram illustrating a printed circuit board (PCB) according to various embodiments of the present disclosure is shown;

[0024] Figure 3 shows an example diagram illustrating a metal cavity structure according to various embodiments of the present disclosure;

[0025] Figure 4 shows example diagrams illustrating example RFID antennas and example radiation patterns of the example RFID antennas according to various embodiments of the present disclosure;

[0026] Figure 5 shows example graphs showing circular polarization (CP) gain versus frequency, voltage standing wave ratio (VSWR) versus frequency, axial ratio versus frequency, and efficiency versus frequency of an example RFID antenna according to various embodiments of the present disclosure;

[0027] Figure 6shows an example diagram illustrating current distribution on a surface of an example RFID antenna according to various embodiments of the present disclosure;

[0028] Fig. 7A An example diagram illustrating an example RFID antenna according to various embodiments of the present disclosure is shown;

[0029] Figure 7B An example diagram illustrating an example RFID antenna according to various embodiments of the present disclosure is shown;

[0030] Figure 7C An example diagram illustrating an example RFID antenna according to various embodiments of the present disclosure is shown;

[0031] Figure 8 shows a block diagram of an example RFID communication system according to various embodiments of the present disclosure; and

[0032] Fig. 9 A block diagram of an example controller of an example RFID communication system is shown according to various embodiments of the present disclosure. DETAILED DESCRIPTION

[0033] Some embodiments of the present disclosure will be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, embodiments of the present disclosure. In fact, these disclosures may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure satisfies applicable legal requirements. Throughout the content, similar reference numerals refer to similar elements.

[0034] As used herein, terms such as "front," "rear," "top," and the like are used for illustrative purposes in the examples provided below to describe the relative positions of certain components or portions of components. In addition, as will be apparent to one of ordinary skill in the art from this disclosure, the terms "substantially" and "approximately" indicate that the referenced element or associated description is accurate within an applicable engineering tolerance.

[0035] As used herein, the term "comprising" means including but not limited to, and should be interpreted in the manner commonly used in the patent context. It should be understood that the use of broad terms such as "comprising," "including," and "having" provides support for narrower terms such as "consisting of," "consisting essentially of," and "consisting essentially of."

[0036] The phrases "in one embodiment," "according to one embodiment," and the like generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure, and may be included in more than one embodiment of the present disclosure (importantly, such phrases are not necessarily referring to the same embodiment).

[0037] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0038] If the specification states that a component or feature "may", "can", "could", "should", "will", "preferably", "likely", "usually", "optionally", "for example", "often", or "might" (or other such language) be included or have a property, the specific component or feature is not required to be included or have that property. Such components or features may optionally be included in some embodiments, or may be excluded.

[0039] The term "loop structure" as used herein corresponds to a closed loop structure formed in the shape of a loop. In an example embodiment, the closed loop structure may include four sides connected by four corners at right angles to each other, and each side of the loop is parallel to the opposite side and all four sides have the same length. Alternatively or additionally, other shapes may take the form of loop structures, such as rectangular shapes.

[0040] The term "slotted structure" as used herein corresponds to an annular structure with slots or openings positioned inside the annular structure. In an exemplary embodiment, the slots or openings are rectangular in shape and have the same width and the same length.

[0041] In some examples, an RFID reader antenna in an RFID communication system transmits an interrogation signal in the form of an electromagnetic wave to an RFID tag disposed on a corresponding object located in a reading zone. In response to the interrogation signal and in some examples, the RFID tag performs backscatter modulation by modulating the magnitude and phase of the scattered electromagnetic wave of the electromagnetic wave emitted from the RFID reader antenna. The backscattered modulated electromagnetic wave is returned to the RFID reader antenna, and the backscattered modulated electromagnetic wave includes information about the corresponding RFID tag in some examples. Therefore, the RFID reader antenna processes the information stored in the internal memory unit of the corresponding RFID tag. In an example in which the RFID tag is a passive tag, the RFID tag also obtains energy from the interrogation signal from the RFID reader antenna.

[0042] RFID reader antennas and / or RFID communication systems may be suitable for use in a variety of applications, such as, but not limited to, tracking automobiles, equipment, parts, components, tools, or other assets in a manufacturing or assembly facility or in a retail store, warehouse, vehicle, cargo container, storage area, hospital, or other facility where assets need to be tracked.

[0043] Various example embodiments solve exemplary technical problems associated with RFID reader antennas (e.g., RFID reader antennas). As understood by those skilled in the art to which the present disclosure pertains, for example, in some examples, the RFID reader antenna can be customized to have a compact size while maintaining low manufacturing cost and good performance of the RFID reader antenna, so that the RFID reader antenna can be easily integrated with other terminal devices.

[0044] Furthermore, in some examples, the communication between the RFID reader antenna and the RFID tag may be affected or otherwise impacted by other objects (e.g., electronic devices). For example, electromagnetic signals radiated from other electronic devices may affect or otherwise impact the communication between the RFID reader antenna and the RFID tag. Therefore, there is a need to improve the signal gain of the RFID reader antenna.

[0045] To address at least these exemplary problems and other problems, the example RFID antenna described herein includes a single integral printed circuit board (PCB). For example, the PCB may include an etched metal layer on a substrate, wherein the etched metal layer has a loop structure as a radiating element and a slotted structure as a grounding element. In some examples, the loop structure and the slotted structure may have beveled edges at corresponding corners so that when the phase of the feed fed to the RFID antenna changes from 0° to 90°, to 180°, and further to 270°, the RFID antenna can operate in circular polarization. For example, the circular polarization (CP) gain of the RFID antenna can reach a peak value of 6.5 decibels, with an isotropic circularly polarized antenna as a reference (dBiC). In some examples, the RFID antenna may have a compact size (e.g., 12cm×12cm) compared to a conventional RFID antenna (e.g., 15cm×15cm). In some examples, the main advantage of the example RFID antenna is the compact size achieved by the loop structure, making the RFID antenna easy to integrate into other terminal devices. Furthermore, in some examples, the operating principle of the circularly polarized RFID antenna is implemented by a loop structure with beveled edges in opposite corners, which in some examples reduces manufacturing costs and improves performance.

[0046] In an alternative or additional example, the example RFID antenna may further include a metal cavity structure to surround the PCB from five sides while leaving one side open to electromagnetic wave radiation from the radiating element. For example, in some examples, the electromagnetic wave radiation from the radiating element may have a directional radiation pattern while detuning caused by objects (e.g., electronic devices) located close to the five sides may be minimized.

[0047] Having generally described example embodiments of the present disclosure, specific features and functionality of the various devices will be described below.

[0048] The components shown in the figures represent components that may or may not be present in the various embodiments of the disclosure described herein, such that an embodiment may include fewer or more components than shown in the figures without departing from the scope of the disclosure.

[0049] Reference now Figure 1 , provides an example diagram illustrating an example RFID antenna 100 according to some example embodiments described herein. Figure 1 As shown, in some examples, the example RFID antenna 100 may include a printed circuit board (PCB) 101 and a metal cavity structure 102. For example, the PCB 101 may be positioned in the metal cavity structure 102 such that the metal cavity structure 102 surrounds the PCB 101 from at least five sides.

[0050] In some embodiments, PCB 101 may include substrate 103 and etched metal layer 104 on substrate 103. In some examples, substrate 103 may be made of glass-reinforced epoxy laminate material. For example, substrate 103 may be made of flame retardant (FR4) material, Teflon, or other PCB materials.

[0051] In some embodiments, etched metal layer 104 may be a single metal layer. For example, etched metal layer 104 may be a single copper layer that is etched. In some examples, etched metal layer 104 may include radiating element 105 and grounding element 106. For example, radiating element 105 and grounding element 106 may be formed on substrate 103.

[0052] In some embodiments, the radiating element 105 can be configured to emit or radiate electromagnetic waves into space or capture incoming electromagnetic waves when receiving, so that the example RFID antenna 100 can be able to communicate with a tag antenna (not shown). For example, the radiating element 105 can be configured to transmit electromagnetic signals to an RFID passive tag antenna to excite the RFID passive tag antenna. In some examples, tag integrated circuit (IC) information can be transmitted back to the example RFID antenna 100 by the RFID passive tag antenna. In some examples, the electromagnetic waves radiated from the radiating element 105 can be circularly polarized.

[0053] In some embodiments, the radiating element 105 may have a loop structure 105a. For example, the loop structure 105a may be a closed loop structure formed in a loop shape. In some examples, the loop structure 105a includes two first beveled edges 110 (e.g., 110a and 110b) formed in first opposing corners 111 (e.g., 111a and 111b) of the loop structure 105a. For example, the two first beveled edges 110 (e.g., 110a and 110b) may be formed in the first opposing corners 111 (e.g., 111a and 111b) from the inner side of the loop structure 105a.

[0054] In some examples, the loop structure may be a square loop structure.

[0055] In some examples, each of the two first beveled edges 110 (e.g., 110a and 110b) can be positioned in each of the first opposing corners 111 (e.g., 111a and 111b) from the inner side of the loop structure 105a so that a chamfered or angled surface (not shown) can be formed. For example, each of the two first beveled edges 110 (e.g., 110a and 110b) can form an inclined transition between adjacent sides of the loop structure 105a.

[0056] In some examples, each of the two first beveled edges 110 (eg, 110a and 110b) may be at 45° relative to an adjacent side of the loop structure 105a.

[0057] In some embodiments, the ground element 106 on the substrate 103 may have a slotted structure 106a that is concentric with the loop structure 105a. For example, the slotted structure 106a may be a square or rectangular shaped structure, wherein the slot or opening 108 is positioned at the center of the square shaped structure. In some examples, the diagonal lines (not shown) of the slotted structure 106a may be aligned with the diagonal lines (not shown) of the loop structure 105a.

[0058] In some embodiments, the slotted structure 106a may be positioned in the inner region 107 of the loop structure 105a. In some examples, the slotted structure 106a may include two first beveled edges 112 (e.g., 112a and 112b) formed on first opposing corners 111 (e.g., 111a and 111b) of the slotted structure 106a. For example, the two first beveled edges 112 (e.g., 112a and 112b) may be formed on the first opposing corners 111 (e.g., 111a and 111b) from the outside of the slotted structure 106a.

[0059] In some examples, each of the two first beveled edges 112 (e.g., 112a and 112b) of the slotted structure 106a can be positioned on each of the first opposing corners 111 (e.g., 111a and 111b) from the outside of the slotted structure 106a so that a chamfered or angled surface (not shown) can be formed. For example, each of the two first beveled edges 112 (e.g., 112a and 112b) of the slotted structure 106a can form an inclined transition between adjacent sides of the slotted structure 106a.

[0060] Reference now Figure 2 , provides an example diagram showing a printed circuit board (PCB) 101 according to some example embodiments described herein. Figure 2 As shown, in some examples, PCB 101 may include substrate 103 and etched metal layer 104 on substrate 103. In some examples, substrate 103 may be made of glass-reinforced epoxy laminate material. For example, substrate 103 may be made of flame retardant (FR4) material, Teflon, or other PCB materials.

[0061] In some embodiments, the etched metal layer 104 can be a single metal layer. For example, the single metal layer can be a single copper layer that is etched. Alternatively or additionally, the single metal layer can be made of other metal materials, such as but not limited to brass, silver, and gold.

[0062] In some examples, the etch metal layer 104 may be formed on the top surface 201 of the substrate 103 .

[0063] Reference now Figure 3 , provides an example diagram illustrating a metal cavity structure 102 according to some example embodiments described herein. Figure 3 As shown, in some examples, the metal cavity structure 102 may include a metal back plate 301 and four metal wall plates 302. For example, the metal back plate 301 may be positioned on a side of the substrate 103 away from the etched metal layer 104, and the four metal wall plates 302 may be positioned on the sidewalls of the PCB 101.

[0064] In some embodiments, the metal cavity structure 102 may be configured to surround the PCB 101 such that electromagnetic wave radiation from the radiating element 105 has a directional radiation pattern.

[0065] In some examples, metal cavity structure 102 may cover PCB 101 from five sides (eg, a side facing metal back plate 301 and four sides facing metal wall plate 302 ) while leaving one side open to electromagnetic wave radiation from radiating element 105 .

[0066] In some examples, the metal back plate 301 can be used as a reflector to reflect electromagnetic waves radiated or emitted from the radiating element 105, so that the electromagnetic wave radiation from the radiating element 105 can have a directional radiation pattern. In some examples, the four metal wall plates 302 can be used to reflect any electromagnetic waves from nearby objects. For example, the nearby object can be an electrical device located close to the metal cavity structure 102.

[0067] Reference now Figure 4 , example diagrams are provided showing an example RFID antenna 400 and example radiation patterns of the example RFID antenna 400 according to some example embodiments described herein.

[0068] like Figure 4 As shown in the left portion of FIG. 4 , in some examples, the example RFID antenna 400 may include a printed circuit board (PCB) 101 and a metal cavity structure 102. For example, the PCB 101 may be positioned in the metal cavity structure 102 such that the metal cavity structure 102 surrounds the PCB 101. In some examples, the metal cavity structure 102 may include a metal back plate 301 and four metal wall plates 302.

[0069] In some embodiments, the metal cavity structure 102 may cover the PCB 101 from five sides (eg, sides facing the metal back plate 301 and the four metal wall plates 302 ) while leaving the remaining sides open to electromagnetic wave radiation from the radiating element 105 .

[0070] In some examples, the metal cavity structure 102 may further include a cover 401 to protect the PCB 101. For example, the cover 401 may be made of a material (eg, plastic) through which electromagnetic wave radiation from the radiation element 105 may pass.

[0071] like Figure 4 As shown in the right part of FIG. 4 , in some examples, the electromagnetic wave radiation from the radiating element 105 may have a directional radiation pattern. For example, the electromagnetic wave radiation energy may be concentrated in the main lobe 402 of the directional radiation pattern. In some examples, the main lobe 402 may be positioned on a side of the cover 401 away from the metal back plate 301.

[0072] For example, the metal back plate 301 may be positioned on a side of the substrate 103 away from the etched metal layer 104 , and the four metal wall plates 302 may be on the sidewalls of the PCB 101 .

[0073] Reference now Figure 5 , provides example graphs showing circular polarization (CP) gain versus frequency, voltage standing wave ratio (VSWR) versus frequency, axial ratio versus frequency, and efficiency versus frequency of an example RFID antenna 100 according to some example embodiments described herein.

[0074] like Figure 5 As shown in the upper left portion of , in some examples, when the frequency of the electromagnetic signal varies within a range from 890 MHz to 940 MHz, the peak CP gain of the example RFID antenna 100 may be approximately 6.5 dBiC.

[0075] like Figure 5 As shown in the upper right portion of , in some examples, when the frequency of the electromagnetic signal is approximately 910 MHz, the VSWR of the example RFID antenna 100 can be approximately 1.5:1.

[0076] like Figure 5 As shown in the lower left portion of FIG. , in some examples, when the frequency of the electromagnetic signal is approximately 915 MHz, the axial ratio of the example RFID antenna 100 can be equal to 1.

[0077] like Figure 5 As shown in the lower right portion of FIG. 1 , in some examples, when the frequency of the electromagnetic signal is approximately 915 MHz, the efficiency of the example RFID antenna 100 can be equal to 90%.

[0078] Reference now Figure 6 , provides an example graph illustrating current distribution on a surface of an example RFID antenna 100 according to some example embodiments described herein.

[0079] In some embodiments, the EM field generated by the example RFID antenna 100 may be a combination of an electric field and a magnetic field. For example, the electric field may be proportional to the current on the surface of the example RFID antenna 100. For example, the electric field E may be calculated by the following formula (Formula 1).

[0080] E = J / σ Formula 1

[0081] where J is the current density on the surface of the RFID antenna, and σ is the conductivity of the material of the RFID antenna.

[0082] For example, the magnetic field may be proportional to the voltage on the surface of the example RFID antenna 100. For example, the magnetic field B may be calculated by the following formula (Formula 2).

[0083] B = V / L Formula 2

[0084] Where V is the voltage on the surface of the RFID antenna, and L is the inductance of the material of the RFID antenna.

[0085] In some embodiments, the current on the surface of the example RFID antenna 100 can be visualized when the current on the surface of the example RFID antenna 100 is fed with different phases. For example, when the phase of the feed fed to the example RFID antenna 100 is changed between 0°, 90°, 180°, and 270°, the current on the surface of the example RFID antenna 100 can be changed individually.

[0086] For example, when the feed fed to the example RFID antenna 100 has a phase of 0°, the direction of the current may be the horizontal direction 601. For example, when the feed fed to the example RFID antenna 100 has a phase of 90°, the direction of the current may be the vertical direction 602. For example, when the feed fed to the example RFID antenna 100 has a phase of 180°, the direction of the current may be the horizontal direction 603. For example, when the feed fed to the example RFID antenna 100 has a phase of 270°, the direction of the current may be the vertical direction 604.

[0087] For example, when the phase feeding method is implemented in the example RFID antenna 100, circular polarization can be achieved.

[0088] In some embodiments, the example RFID antenna 100 can operate in circular polarization. Figure 6 As shown, in some examples, when the phase of the current on the surface of the example RFID antenna 100 changes from 0° to 90°, to 180°, and further to 270°, the current on the surface of the example RFID antenna 100 can change in a circular manner.

[0089] Reference now Fig. 7A , provides an example diagram illustrating an example RFID antenna 700A according to some example embodiments described herein. Fig. 7A As shown, in some examples, an example RFID antenna 700A may include a printed circuit board (PCB) 701 and a metal cavity structure 702. For example, the PCB 701 may be positioned in the metal cavity structure 702 such that the metal cavity structure 702 surrounds the PCB 701.

[0090] In some embodiments, PCB 701 may include substrate 703 and etched metal layer 704 on substrate 703. In some examples, substrate 103 may be made of glass-reinforced epoxy laminate material. For example, substrate 103 may be made of flame retardant (FR4) material, Teflon, or other PCB materials.

[0091] In some embodiments, the etched metal layer 704 can be a single metal layer. For example, the etched metal layer 704 can be a single copper layer etched. In some examples, the etched metal layer 704 can include a radiating element 705 and a grounding element 706. For example, the radiating element 705 and the grounding element 706 can be formed on the substrate 703.

[0092] In some embodiments, the radiating element 705 may be configured to emit or radiate electromagnetic waves into space or capture incoming electromagnetic waves when receiving, so that the example RFID antenna 700A may be able to communicate with a tag antenna (not shown). For example, the radiating element 705 may be configured to emit or radiate electromagnetic signals to an RFID passive tag antenna to excite the RFID passive tag antenna. In some examples, tag integrated circuit (IC) information may be transmitted back to the example RFID antenna 700A by the RFID passive tag antenna. In some examples, the electromagnetic waves radiated from the radiating element 705 may be circularly polarized.

[0093] In some embodiments, the radiation element 705 may have a loop structure 705a. For example, the loop structure 705a may be a closed loop structure formed in a square shape.

[0094] In some examples, the loop structure 705a may include two first beveled edges 710 (e.g., 710a and 710b) formed in a first relative corner 711 (e.g., 711a and 711b) of the loop structure 705a and two second beveled edges 720 (e.g., 720a and 720b) ​​formed in a second relative corner 721 (e.g., 721a and 721b) of the loop structure 705a. For example, the two first beveled edges 710 (e.g., 710a and 710b) may be formed in the first relative corner 711 (e.g., 711a and 711b) from the inner side of the loop structure 705a. For example, the two second beveled edges 720 (e.g., 720a and 720b) ​​may be formed in the second relative corner 721 (e.g., 721a and 721b) from the inner side of the loop structure 705a.

[0095] In some examples, each of the two first beveled edges 710 (e.g., 710a and 710b) and the two second beveled edges 720 (e.g., 720a and 720b) ​​may be positioned in each of the first relative corners 711 (e.g., 711a and 711b) or the second relative corners 721 (e.g., 721a and 721b) from the inner side of the loop structure 705a, respectively, so that a chamfered or angled surface (not shown) is formed. For example, each of the two first beveled edges 710 (e.g., 710a and 710b) and the two second beveled edges 720 (e.g., 720a and 720b) ​​may form an inclined transition between adjacent sides of the loop structure 705a.

[0096] In some examples, each of the two first beveled edges 710 (eg, 710a and 710b) and the two second beveled edges 720 (eg, 720a and 720b) ​​may be at 45° relative to an adjacent side of the loop structure 705a.

[0097] In some embodiments, the ground element 706 on the substrate 703 may have a slotted structure 706a that is concentric with the loop structure 705a. For example, the slotted structure 706a may be a square or rectangular shaped structure, wherein the slot or opening 708 is positioned at the center of the square / rectangular shaped structure. In some examples, the diagonal lines (not shown) of the slotted structure 706a may be aligned with the diagonal lines (not shown) of the loop structure 705a.

[0098] In some embodiments, the slotted structure 706a can be positioned in the interior region 707 of the loop structure 705a.

[0099] In some examples, the slotted structure 706a may include two first beveled edges 712 (e.g., 712a and 712b) and two second beveled edges 722 (e.g., 722a and 722b) formed on the first relative corner 711 (e.g., 711a and 711b) and the second relative corner 721 (e.g., 721a and 721b) from the outside of the slotted structure 706a, respectively. For example, the two first beveled edges 712 (e.g., 712a and 712b) may be formed on the first relative corner 711 (e.g., 711a and 711b) from the outside of the slotted structure 706a. For example, the two second beveled edges 722 (e.g., 722a and 722b) may be formed on the second relative corner 721 (e.g., 721a and 721b) from the outside of the slotted structure 706a.

[0100] In some examples, each of the two first beveled edges 712 (e.g., 712a and 712b) and the two second beveled edges 722 (e.g., 722a and 722b) of the slotted structure 706a may be positioned outside each of the first relative corners 711 (e.g., 711a and 711b) or the second relative corners 721 (e.g., 721a and 721b) of the slotted structure 706a, respectively, so that a chamfered or angled surface (not shown) is formed. For example, each of the two first beveled edges 712 (e.g., 712a and 712b) of the slotted structure 706a may form an inclined transition between adjacent sides of the slotted structure 706a. For example, each of the two second beveled edges 722 (e.g., 722a and 722b) of the slotted structure 706a may form an inclined transition between adjacent sides of the slotted structure 706a.

[0101] In some embodiments, the first two opposing corners 711 of the slotted structure 706a can be different from the second two opposing corners 721 of the slotted structure 706a.

[0102] In some embodiments, each of the two first beveled edges 710 (e.g., 710a and 710b) of the loop structure 705a has a first width W1. In some embodiments, each of the two second beveled edges 720 (e.g., 720a and 720b) ​​of the loop structure 705a has a second width W2.

[0103] In some examples, the first width W1 can be different from the second width W2.

[0104] Figure 8 800 , a first memory device 804, a first communication interface 806, an RFID encoder 808, an RFID reader 810, a verification unit 812, a power modification unit 814, and an RFID antenna 816. In some examples, the RFID antenna 816 of the example RFID communication system 800 described herein may correspond to Figure 1 The RFID antenna 100, as Figure 4 The RFID antenna 400, as Fig. 7A The RFID antenna 700A, as Figure 7B The RFID antenna 700B and Figure 7C The RFID antenna 700C.

[0105] Reference Figure 7B, provides an example diagram illustrating an example RFID antenna 700B according to some example embodiments described herein. Figure 7B As shown, in some examples, an example RFID antenna 700B may include a printed circuit board (PCB) 701 and a metal cavity structure 702. For example, the PCB 701 may be positioned in the metal cavity structure 702 such that the metal cavity structure 702 surrounds the PCB 701.

[0106] In some embodiments, PCB 701 may include substrate 703 and etched metal layer 704 on substrate 703. In some examples, substrate 103 may be made of glass-reinforced epoxy laminate material. For example, substrate 103 may be made of flame retardant (FR4) material, Teflon, or other PCB materials.

[0107] In some embodiments, the etched metal layer 704 can be a single metal layer. For example, the etched metal layer 704 can be a single copper layer etched. In some examples, the etched metal layer 704 can include a radiating element 705 and a grounding element 706. For example, the radiating element 705 and the grounding element 706 can be formed on the substrate 703.

[0108] In some embodiments, the radiating element 705 may be configured to emit or radiate electromagnetic waves into space or capture incoming electromagnetic waves when receiving, so that the example RFID antenna 700B may be able to communicate with a tag antenna (not shown). For example, the radiating element 705 may be configured to emit or radiate electromagnetic signals to an RFID passive tag antenna to excite the RFID passive tag antenna. In some examples, tag integrated circuit (IC) information may be transmitted back to the example RFID antenna 700B by the RFID passive tag antenna.

[0109] In some embodiments, the radiation element 705 may have a loop structure 705a. For example, the loop structure 705a may be a closed loop structure formed in a square shape.

[0110] In some examples, the loop structure 705a may include four first beveled edges 710 formed in four corners 711 of the loop structure 705a. For example, the four first beveled edges 710 may be formed in the four corners 711 from the inner side of the loop structure 705a.

[0111] In some examples, each of the four first beveled edges 710 can be positioned in each of the four corners 711 from the inner side of the loop structure 705a, respectively, so that a chamfer or angled surface (not shown) is formed. For example, each of the four first beveled edges 710 can form an inclined transition between adjacent sides of the loop structure 705a.

[0112] In some examples, each of the four beveled edges can be at 45° relative to an adjacent side of the loop structure 705a.

[0113] In some embodiments, the ground element 706 on the substrate 703 may have a slotted structure 706a that is concentric with the loop structure 705a. For example, the slotted structure 706a may be a square or rectangular shaped structure, wherein the slot or opening 708 is positioned at the center of the square / rectangular shaped structure. In some examples, the diagonal lines (not shown) of the slotted structure 706a may be aligned with the diagonal lines (not shown) of the loop structure 705a.

[0114] In some embodiments, the slotted structure 706a can be positioned in the interior region 707 of the loop structure 705a.

[0115] In some examples, the slotted structure 706a may include four second beveled edges 712 formed on four corners 711 from outside the slotted structure 706a, respectively. For example, the four second beveled edges 712 may be formed on four corners 711 from outside the slotted structure 706a.

[0116] In some examples, each of the four second beveled edges 712 of the slotted structure 706a can be positioned outside each of the four corners 711 of the slotted structure 706a, respectively, so that a chamfered or angled surface (not shown) is formed. For example, each of the four second beveled edges 712 of the slotted structure 706a can form an inclined transition between adjacent sides of the slotted structure 706a.

[0117] In some embodiments, each of the four first beveled edges 710 of the loop structure 705a has the same width W. In some examples, the electromagnetic waves radiated from the radiating element 705 of the example RFID antenna 700B can be linearly polarized.

[0118] Reference Figure 7C , provides an example diagram illustrating an example RFID antenna 700C according to some example embodiments described herein. Figure 7C As shown, in some examples, an example RFID antenna 700C may include a printed circuit board (PCB) 701 and a metal cavity structure 702. For example, the PCB 701 may be positioned in the metal cavity structure 702 such that the metal cavity structure 702 surrounds the PCB 701.

[0119] In some embodiments, PCB 701 may include substrate 703 and etched metal layer 704 on substrate 703. In some examples, substrate 103 may be made of glass-reinforced epoxy laminate material. For example, substrate 103 may be made of flame retardant (FR4) material, Teflon, or other PCB materials.

[0120] In some embodiments, the etched metal layer 704 can be a single metal layer. For example, the etched metal layer 704 can be a single copper layer etched. In some examples, the etched metal layer 704 can include a radiating element 705 and a grounding element 706. For example, the radiating element 705 and the grounding element 706 can be formed on the substrate 703.

[0121] In some embodiments, the radiating element 705 may be configured to emit or radiate electromagnetic waves into space or capture incoming electromagnetic waves when receiving, so that the example RFID antenna 700C may be able to communicate with a tag antenna (not shown). For example, the radiating element 705 may be configured to emit or radiate electromagnetic signals to an RFID passive tag antenna to excite the RFID passive tag antenna. In some examples, tag integrated circuit (IC) information may be transmitted back to the example RFID antenna 700C by the RFID passive tag antenna.

[0122] In some embodiments, the radiation element 705 may have a loop structure 705a. For example, the loop structure 705a may be a closed loop structure formed in a square shape.

[0123] In some examples, the loop structure 705a may include four first beveled edges 710 formed on four corners 711 of the loop structure 705a. For example, the four first beveled edges 710 may be formed in the four corners 711 from the inner side of the loop structure 705a.

[0124] In some examples, each of the four first beveled edges 710 can be positioned in each of the four corners 711 from the inner side of the loop structure 705a, respectively, so that a chamfer or angled surface (not shown) is formed. For example, each of the four first beveled edges 710 can form an inclined transition between adjacent sides of the loop structure 705a.

[0125] In some examples, each of the four beveled edges can be at 45° relative to an adjacent side of the loop structure 705a.

[0126] In some embodiments, the loop structure 705a may include four second beveled edges 713 formed on four corners 711 from the outside of the loop structure 705a, respectively. For example, the four second beveled edges 713 may be formed on four corners 711 from the outside of the loop structure 705a.

[0127] In some examples, each of the four second beveled edges 713 of the loop structure 705a can be positioned outside each of the four corners 711 of the loop structure 705a, respectively, so that a chamfered or angled surface (not shown) is formed. For example, each of the four second beveled edges 713 of the loop structure 705a can form an inclined transition between adjacent sides of the slotted structure 705a.

[0128] In some embodiments, the ground element 706 on the substrate 703 may have a slotted structure 706a that is concentric with the loop structure 705a. For example, the slotted structure 706a may be a square or rectangular shaped structure, wherein the slot or opening 708 is positioned at the center of the square / rectangular shaped structure. In some examples, the diagonal lines (not shown) of the slotted structure 706a may be aligned with the diagonal lines (not shown) of the loop structure 705a.

[0129] In some embodiments, the slotted structure 706a can be positioned in the interior region 707 of the loop structure 705a.

[0130] In some examples, the slotted structure 706a may include four third beveled edges 712 formed on four corners 711 from outside the slotted structure 706a, respectively. For example, the four third beveled edges 712 may be formed on four corners 711 from outside the slotted structure 706a.

[0131] In some examples, each of the four third beveled edges 712 of the slotted structure 706a can be positioned outside each of the four corners 711 of the slotted structure 706a, respectively, so that a chamfered or angled surface (not shown) is formed. For example, each of the four third beveled edges 712 of the slotted structure 706a can form an inclined transition between adjacent sides of the slotted structure 706a.

[0132] In some embodiments, each of the four first beveled edges 710 of the loop structure 705a has the same width W.

[0133] In some embodiments, the example RFID antenna 700C can be configured to tune the operating frequency of the example RFID antenna 700C.

[0134] Figure 8800 , a first memory device 804, a first communication interface 806, an RFID encoder 808, an RFID reader 810, a verification unit 812, a power modification unit 814, and an RFID antenna 816. In some examples, the RFID antenna 816 of the example RFID communication system 800 described herein may correspond to Figure 1 The RFID antenna 100, as Figure 4 The RFID antenna 400, as Fig. 7A The RFID antenna 700A, as Figure 7B The RFID antenna 700B and Figure 7C The RFID antenna 700C.

[0135] The controller 802 may be embodied as a component including one or more microprocessors with an accompanying digital signal processor, one or more processors without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuits, one or more computers, various other processing elements (including integrated circuits such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs)), or some combination thereof. Thus, although in Figure 8 802 is shown as a single controller, but in one embodiment, the controller 802 may include multiple controllers and signal processing modules. The multiple controllers may be implemented on a single electronic device, or may be distributed on multiple electronic devices that are collectively configured to function as the circuits of the example RFID communication system 800. The multiple controllers may be in operative communication with each other, and may be collectively configured to perform one or more functions of the circuits of the example RFID communication system 800 as described herein. In an example embodiment, the controller 802 may be configured to execute instructions stored in the first memory device 804 or otherwise accessible to the controller 802. When these instructions are executed by the controller 802, the circuits of the example RFID communication system 800 may be caused to perform one or more functions as described herein.

[0136] Whether the controller 802 is configured by a hardware approach, a firmware / software approach, or a combination thereof, the controller may include an entity capable of being configured accordingly while performing operations according to embodiments of the present disclosure. Thus, for example, when the controller 802 is embodied as an ASIC, FPGA, etc., the controller 802 may include specially configured hardware for performing one or more operations described herein. Alternatively, as another example, when the controller 802 is embodied as an executor of instructions (such as may be stored in the first memory device 804), these instructions may specifically configure the controller 802 to perform one or more algorithms and operations described herein.

[0137] Therefore, controller 802 used herein may refer to a programmable microprocessor, a microcomputer, or one or more multiprocessor chips that can be configured by software instructions (applications) to perform various functions including the functions of the various embodiments described above. In some devices, multiple processors dedicated to wireless communication functions and a processor dedicated to running other applications may be provided. Software applications may be stored in internal memory before being accessed and loaded into the processor. The processor may include an internal memory sufficient to store application software instructions. In many devices, the internal memory may be a volatile or non-volatile memory such as a flash memory or a mixture of the two. The memory may also be located inside another computing resource (e.g., enabling computer-readable instructions to be downloaded via the Internet or another wired or wireless connection).

[0138] The first memory device 804 may include suitable logic components, circuits and / or interfaces suitable for storing a set of instructions that can be executed by the controller 802 to perform predetermined operations. Some of the commonly known memory implementations include, but are not limited to, hard disks, random access memories, cache memories, read-only memories (ROMs), erasable programmable read-only memories (EPROMs) and electrically erasable programmable read-only memories (EEPROMs), flash memory, cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, compact disk read-only memories (CD-ROMs), digital versatile disk read-only memories (DVD-ROMs), optical disks, circuits configured to store information, or some combination thereof. In one embodiment, without departing from the scope of the present disclosure, the first memory device 804 may be integrated with the controller 802 on a single chip.

[0139] The first communication interface 806 may correspond to a communication interface that may facilitate sending and receiving messages and data to and from various components of the example RFID communication system 800. Examples of communication interfaces may include, but are not limited to, an antenna, an Ethernet port, a USB port, a serial port, or any other port that may be suitable for receiving and transmitting data. The communication interface transmits and receives data and / or messages according to various communication protocols, such as I2C, TCP / IP, UDP, and 2G, 3G, 4G, or 5G communication protocols.

[0140] The RFID encoder 808 includes suitable logic components and circuits for encoding electromagnetic signal data. In some example embodiments, the RFID encoder 808 encodes the electromagnetic signal data according to one or more of the electronic product code (EPC) or the Department of Defense (DOD) format. In some examples, the RFID encoder 808 may be configured to transmit data on one or more frequency bands such as, but not limited to, 13.56 MHz (hereinafter referred to as "high frequency band" or "HF") or 860 MHz-960 MHz (hereinafter referred to as "UHF band") through the RFID antenna 816. In addition, the RFID encoder 808 may be configured to modulate the data on the RF carrier of the HF band or the UHF band before transmitting the data. Some examples of modulation techniques used by the RFID encoder 808 include, but are not limited to, phase jitter modulation (PJM), amplitude shift keying (ASK), and the like.

[0141] In some examples, the RFID encoder 808 may be configured to transmit one or more commands to the RFID passive tag antenna, so that the RFID passive tag antenna performs a predetermined operation according to the one or more commands. For example, the RFID encoder 808 may transmit a command "write" that instructs the RFID passive tag antenna to write data accompanying the command into the memory of the RFID passive tag antenna. Similarly, the RFID encoder 808 may transmit other commands to the RFID passive tag antenna, such as but not limited to "lock", "access", "block write" and / or any other command according to the EPC global standard.

[0142] The RFID reader 810 includes suitable logic components and circuits for reading data from the RFID passive tag antenna. In order to read the data encoded in the RFID passive tag antenna, the RFID reader 810 may transmit an interrogation command to the RFID inlay on one or more frequency bands (such as HF and UHF). In addition, similar to the RFID encoder 808, the RFID reader 810 may also utilize one or more modulation techniques (such as ASK and PJM) to transmit the interrogation command on one or more frequency bands. In response to the interrogation command, the RFID reader 810 may receive the encoded data from the RFID passive tag antenna. In an example embodiment, the RFID reader 810 may utilize the RFID antenna 816 to transmit the interrogation command and receive the encoded data from the RFID passive tag antenna.

[0143] In some examples, both the RFID reader 810 and the RFID encoder 808 may include one or more of the following: filters, analog-to-digital (A / D) converters, digital-to-analog (D / A) converters, matching circuits, amplifiers, and / or tuners that enable the RFID reader 810 and the RFID encoder 808 to transmit and receive data over one or more frequency bands via the RFID antenna 816.

[0144] The verification unit 812 includes suitable logic components and circuits configured to verify whether the encoding of the RFID passive tag antenna is successful. In some examples, in order to determine whether the encoding is successful, the verification unit 812 can determine the encoding success rate. The verification unit 812 can be implemented using one or more hardware components (such as but not limited to FPGA, ASIC, etc.).

[0145] The power modification unit 814 includes suitable logic components and circuits configured to manage the signal transmission power of the RFID antenna 816. In an example embodiment, the signal transmission power corresponds to the transmitter power output of the signal transmitted from the RFID antenna 816. In an example embodiment, the power modification unit 814 can be configured to modify the signal transmission power according to a plurality of power settings. In an example embodiment, the power setting can correspond to the value of the signal transmission power used to transmit data from the RFID antenna 816. In some examples, the power modification unit 814 can modify the input voltage of the RFID antenna 816 to modify the signal transmission power. In an example embodiment, the power modification unit 814 can modify the signal transmission power in response to instructions received from the controller 802. The power modification unit 814 can be implemented using one or more hardware components (such as, but not limited to, FPGA, ASIC, etc.).

[0146] Fig. 9A block diagram of a controller 802 of an example RFID communication system 800 is shown according to one or more embodiments described herein. The controller 802 includes a processor 902, a second memory device 904, a second communication interface 906, an input / output (I / O) device interface unit 908, a calibration unit 910, an encoding operation unit 912, and a signal processing unit 914.

[0147] Processor 902 may be embodied as a component including one or more microprocessors with an accompanying digital signal processor, one or more processors without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuits, one or more computers, various other processing elements (including integrated circuits such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs)), or some combination thereof. Thus, although in Fig. 9 802. Although shown as a single processor in FIG. 804, in one embodiment, the processor 902 may include multiple processors and signal processing modules. The multiple processors may be embodied on a single electronic device or may be distributed on multiple electronic devices that are collectively configured to function as circuits of the controller 802. The multiple processors are in operative communication with each other and may be collectively configured to perform one or more functions of the circuits of the controller 802 described herein. In an example embodiment, the processor 902 may be configured to execute instructions stored in the second memory device 904 or otherwise accessible to the processor 902. These instructions, when executed by the processor 902, may cause the circuits of the controller 802 to perform one or more functions, as described herein.

[0148] Whether the processor 902 is configured by a hardware method, a firmware / software method, or a combination thereof, the processor may include an entity capable of performing operations according to the embodiments of the present disclosure while being configured accordingly. Thus, for example, when the processor 902 is embodied as an ASIC, FPGA, etc., the processor 902 may include specially configured hardware for performing one or more operations described herein. Alternatively, as another example, when the processor 902 is embodied as an executor of instructions (such as those that may be stored in the second memory device 904), these instructions may specifically configure the processor 902 to perform one or more algorithms and operations described herein.

[0149] Therefore, processor 902 used herein may refer to a programmable microprocessor, a microcomputer, or one or more multiprocessor chips that can be configured by software instructions (applications) to perform various functions including the functions of the various embodiments described above. In some devices, multiple processors dedicated to wireless communication functions and a processor dedicated to running other applications may be provided. Software applications may be stored in an internal memory before being accessed and loaded into the processor. The processor may include an internal memory sufficient to store application software instructions. In many devices, the internal memory may be a volatile or non-volatile memory such as a flash memory or a mixture of the two. The memory may also be located inside another computing resource (e.g., enabling computer-readable instructions to be downloaded via the Internet or another wired or wireless connection).

[0150] The second memory device 904 may include suitable logic components, circuits and / or interfaces suitable for storing a set of instructions that can be executed by the processor 902 to perform predetermined operations. Some of the commonly known memory implementations include, but are not limited to, hard disks, random access memories, cache memories, read-only memories (ROMs), erasable programmable read-only memories (EPROMs) and electrically erasable programmable read-only memories (EEPROMs), flash memory, cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, compact disk read-only memories (CD-ROMs), digital versatile disk read-only memories (DVD-ROMs), optical disks, circuits configured to store information, or some combination thereof. In an example embodiment, without departing from the scope of the present disclosure, the second memory device 904 may be integrated with the processor 902 on a single chip.

[0151] The second communication interface 906 may correspond to a second communication interface 906 that can facilitate the transmission of messages and data to various devices and the reception of messages and data from these devices. For example, the second communication interface 906 is communicatively coupled to a computing device (not shown). For example, through the second communication interface 906, the example RFID communication system 800 may be configured to receive a command / job from a computing device, and the example RFID communication system 800 may perform a predetermined operation based on the command / job. Examples of the second communication interface 906 may include, but are not limited to, an antenna, an Ethernet port, a USB port, a serial port, or any other port that may be suitable for receiving and transmitting data. The second communication interface 906 transmits and receives data and / or messages according to various communication protocols (such as I2C, TCP / IP, UDP, and 2G, 3G, 4G, or 5G communication protocols).

[0152] The I / O device interface unit 908 may include suitable logic components and / or circuits that may be configured to communicate with the I / O device according to one or more device communication protocols such as, but not limited to, an I2C communication protocol, a serial peripheral interface (SPI) communication protocol, a serial communication protocol, a controller area network (CAN) communication protocol, and a Communication protocols) to communicate with one or more components of the example RFID communication system 800. In an example embodiment, the I / O device interface unit 908 can communicate with other components of the example RFID communication system 800. Some examples of the I / O device interface unit 908 can include, but are not limited to, a data acquisition (DAQ) card, an electric drive driver circuit, and the like.

[0153] The calibration unit 910 may include suitable logic and / or circuitry for calibrating the example RFID communication system 800. In an example embodiment, the calibration unit 910 may be configured to determine one or more characteristics of the example RFID antenna 800. The calibration unit 910 may be implemented using one or more hardware components such as, but not limited to, an FPGA, an ASIC, etc.

[0154] The encoding operation unit 912 may include suitable logic components and / or circuits for operating the example RFID communication system 800 in the encoding mode. In an example embodiment, the encoding operation unit 912 may be configured to cause the RFID encoder 808 in the example RFID communication system 800 to encode the RFID passive tag antenna through the RFID antenna 816. The encoding operation unit 912 may be implemented using one or more hardware components (such as, but not limited to, FPGA, ASIC, etc.).

[0155] The signal processing unit 914 may include suitable logic components and / or circuits for analyzing the input signal received from the media sensor. For example, the signal processing unit 914 may include a digital signal processor (e.g., 902) that may be configured to identify peaks and valleys in the input signal. In addition, the signal processing unit 914 may analyze the input signal using one or more signal processing techniques such as, but not limited to, a fast Fourier transform (FFT), a discrete Fourier transform (DFT), a discrete time Fourier transform (DTFT). The signal processing unit 914 may be implemented using one or more hardware components such as, but not limited to, an FPGA, an ASIC, etc.

[0156] In some examples, the scope of the present disclosure is not limited to having a separate controller 802 for the example RFID communication system 800. In an alternative embodiment, the various units / modules of the controller 802 can be implemented on the example RFID communication system 800, thereby forming an integrated single device, without departing from the scope of the present disclosure. In another alternative embodiment, the various functions of the example RFID communication system 800 can be implemented in the controller 802, thereby forming an integrated single device, without departing from the scope of the present disclosure. In such a specific implementation, the RFID antenna 816 can be directly communicatively coupled to the controller 802.

[0157] As described above and as will be understood based on the present disclosure, the embodiments of the present disclosure may include various components, including complete hardware or any combination of software and hardware. In addition, the embodiment may take the form of a computer program product on at least one non-transient computer-readable storage medium, and the computer program product has computer-readable program instructions (e.g., computer software) embodied in the storage medium. Similarly, the embodiment may take the form of a computer program code stored on at least one non-transient computer-readable storage medium. Any suitable computer-readable storage medium may be utilized, including a non-transient hard disk, a CD-ROM, a flash memory, an optical storage device, or a magnetic storage device.

[0158] It should be understood that the disclosure is not limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation unless otherwise specified.

Claims

1. A radio frequency identification (RFID) antenna, comprising a printed circuit board (PCB), wherein the PCB comprises: substrate; The etched metal layer on the substrate, wherein the etched metal layer comprises: a radiating element positioned on the substrate, the radiating element having a loop structure, wherein the loop structure includes two first beveled edges, and the two first beveled edges are positioned on opposite corners of the loop structure; as well as A ground element is positioned on the substrate, the ground element having a slotted structure that is concentric with the loop structure and is positioned in an inner region of the loop structure.

2. The RFID antenna according to claim 1, further comprising: A metal cavity structure, wherein the metal cavity surrounds the PCB, so that the electromagnetic wave radiation from the radiating element emits a directional radiation pattern.

3. The RFID antenna according to claim 2, wherein the metal cavity structure comprises a metal back plate and a metal wall plate, wherein the metal back plate is positioned on a side of the substrate away from the etched metal layer, and the metal wall plate is positioned on a side wall of the PCB.

4. The RFID antenna according to claim 3, wherein: The metal cavity structure further includes a plastic sheet covering the PCB in the metal cavity structure.

5. The RFID antenna according to claim 1, wherein the substrate is made of a flame retardant (FR4) material or Teflon.

6. The RFID antenna according to claim 1, wherein: The slotted structure also includes beveled edges on at least two opposing corners of the slotted structure.

7. The RFID antenna according to claim 1, wherein: The loop structure is a square loop structure, and Each of the two first beveled edges of the loop structure is at 45° relative to an adjacent side of the loop structure.

8. The RFID antenna according to claim 1, wherein: The loop structure also includes two second beveled edges in second two opposing corners of the loop structure.

9. The RFID antenna according to claim 8, wherein: The two first beveled edges of the loop structure have a first width, The two second beveled edges of the loop structure have a second width, and the first width is different from the second width.

10. The RFID antenna according to claim 8, wherein: The slotted structure further includes two first beveled edges on first two opposite corners of the slotted structure and two second beveled edges on second two opposite corners of the slotted structure.

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