Antenna structure and transceiver device

Abstract

This application relates to an antenna structure and transceiver device, applicable to the field of antennas. The antenna structure includes a radiator, a director, a reflector, and a tuner. The radiator is a non-closed ring structure formed by bending a continuous conductor and has a recess. The continuous conductor includes a first free end and a second free end spaced apart, with a feed gap formed between the first and second free ends. The feed gap is located at the middle position of the radiator in the width direction. The director is located on one side of the radiator. The reflector is located on the opposite side of the radiator and the director. The tuner connects the radiator, director, and reflector into a single structure. This application achieves a high degree of integration and simplification in the antenna structure by using a radiator formed by bending a continuous conductor and creating a direct feed gap, combined with a director and a reflector, and integrating the three into a single structure by a tuner. This also provides a foundation for obtaining stable directional radiation performance.

Description

Technical Field

[0001] This application relates to the technical field of antennas, and in particular to an antenna structure and transceiver device. Background Technology

[0002] Ultra-high frequency radio frequency identification (UHF RFID) technology has been widely used in logistics, retail, and asset management, among other fields. Handheld readers and writers, in particular, have seen continuous market demand growth due to their portability. To address the issue of random tag orientation, current handheld devices primarily employ circularly polarized antenna designs, with ceramic microstrip antennas and four-arm helical antennas being the mainstream implementation solutions.

[0003] However, while ceramic antennas are low in cost, they have limited gain and narrow bandwidth, which severely restricts the readout distance. Quad-arm helical antennas have improved performance, but they rely on complex power divider feed networks, which not only introduce signal loss leading to a reduction in effective gain, but also increase the complexity of the structure and production costs.

[0004] In summary, antenna designs aimed at improving gain and directivity are often complex and bulky, making them unsuitable for the compact space of handheld devices; while antennas designed for miniaturization often fail to meet the performance requirements for accurate long-range identification. Some compromise solutions attempt to balance size and performance, but these are usually based on traditional antenna forms, making it difficult to achieve a balance between gain, cost, and structural simplicity. Summary of the Invention

[0005] Therefore, it is necessary to provide an antenna structure and transceiver device to address the problem that existing portable UHF RFID device antennas cannot simultaneously achieve high gain, strong directivity, and structural simplification under miniaturization constraints.

[0006] In a first aspect, this application provides an antenna structure, which adopts the following technical solution:

[0007] An antenna structure includes a radiator, a director, a reflector, and a tuner. The radiator is constructed as a non-closed ring structure formed by bending a continuous conductor and has a recess. The continuous conductor includes a first free end and a second free end spaced apart, with a feed gap formed between the first and second free ends, the feed gap being located at the midpoint of the radiator in the width direction. The director is disposed on one side of the radiator. The reflector is disposed on the opposite side of the radiator from the director. The tuner connects the radiator, the director, and the reflector into a single structure.

[0008] In one embodiment, the director is configured as a U-shaped director, and the reflector is configured as a U-shaped reflector.

[0009] In one embodiment, the outer contours of the U-shaped director, the radiator, and the U-shaped reflector are consistent.

[0010] In one embodiment, the tuner is a Type I tuner, which is used to coaxially connect the radiator, the director, and the reflector, and is circuitally equivalent to a capacitor element to fine-tune the resonant frequency of the antenna structure.

[0011] In one embodiment, the radiator and the tuner together form an integrated radiating structure, which is configured to simultaneously function as an active oscillator, an impedance transformer, and a balun.

[0012] In one embodiment, the reflector satisfies the following relationship: L1 = 1.05λ ~ 1.1λ; the director satisfies the following relationship: L2 = 0.85λ ~ 0.95λ; where L1 is the length of the reflector, L2 is the length of the director, and λ is the wavelength of the center frequency of the operating frequency band.

[0013] In one embodiment, the antenna structure further includes a support member disposed parallel to the tuner and connected to the reflector, the radiator and the director, respectively.

[0014] In one embodiment, two supports are provided, one of which is connected to one side of the reflector, the radiator and the director along the width direction, and the other support is connected to the other side of the reflector, the radiator and the director along the width direction.

[0015] Secondly, this application provides a transceiver device, which adopts the following technical solution:

[0016] A transceiver device includes a housing, a circuit module, and the aforementioned antenna structure. The circuit module is disposed within the housing, and the antenna structure is disposed within the housing or on the surface of the housing and is electrically connected to the circuit module.

[0017] In one embodiment, the housing includes a handheld housing or a wearable housing.

[0018] The antenna structure described above achieves a high degree of integration and simplification in its structure by using a radiator formed by bending a continuous conductor to create a direct feed gap, combined with a director and a reflector, and integrating the three into a single structure by a tuner. This also provides a foundation for obtaining stable directional radiation performance. Attached Figure Description

[0019] Figure 1This is a three-dimensional structural diagram of the antenna structure in one embodiment of this application.

[0020] Figure 2 This is a gain curve of the antenna structure in a simulation software according to one embodiment of this application.

[0021] Figure 3 This is a 3D radiation pattern of the antenna structure in antenna simulation software according to one embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the return loss of the antenna structure in antenna simulation software in one embodiment of this application.

[0023] Attached image annotations:

[0024] 1. Radiator; 11. First free end; 12. Second free end; 13. Feed gap; 2. Director; 3. Reflector; 4. Tuner; 5. Support. Detailed Implementation

[0025] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0026] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0027] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0030] If an element is described as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element present. Where applicable, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation. As described in the background art, the main pain point of UHF RFID device antennas in the current industry is their low gain and poor directionality. Especially in scenarios such as RFID tag reading on high-level shelves in logistics warehouses and assets on high outdoor poles, portable handheld or other portable reader devices need to cover a longer reading distance.

[0031] To address the aforementioned issues, developing a compact antenna structure that requires no complex external matching network and provides high-gain directional radiation is beneficial for improving the overall performance and market competitiveness of portable UHF RFID devices. Therefore, this application provides an antenna structure with a smaller structural size and a longer reading distance, as well as a transceiver device using this antenna structure, to resolve the contradiction in existing portable reader / writer solutions between miniaturization, high gain, and low cost optimization.

[0032] The following is in conjunction with the appendix Figure 1-4 The embodiments of this application will be described in further detail.

[0033] See Figure 1 , Figure 1 A three-dimensional structural diagram of an antenna structure according to an embodiment of this application is shown. One embodiment of this application provides an antenna structure, specifically a Yagi antenna structure, which includes a radiator 1, a director 2, a reflector 3, and a tuner 4.

[0034] In this design, radiator 1, acting as an active oscillator, is constructed as a non-closed ring structure formed by bending a continuous conductor. Radiator 1 has a concave portion, giving it an overall inverted concave shape. After bending, the continuous conductor does not close at both ends, thus forming a first free end 11 and a second free end 12 spaced apart. Director 2 and reflector 3 are both constructed as closed ring structures, and both directors 2 and reflectors 3 are constructed as inverted concave structures similar to the outer contour of radiator 1.

[0035] Specifically, the gap between the first free end 11 and the second free end 12 of the continuous conductor constitutes the direct feed gap 13 of the antenna structure, through which radio frequency signals are fed in or extracted. In this embodiment, the feed gap 13 is located at the middle position of the radiator 1 in the width direction. This inverted concave design formed by bending a single conductor allows the current to be distributed in phase along a preset path, which is the basic physical structure for realizing the miniaturization of the antenna element.

[0036] Continue reading Figure 1 As shown, director 2 is located on one side of radiator 1, and reflector 3 is located on the opposite side of director 2. Director 2 is specifically constructed as a U-shaped director, and reflector 3 is specifically constructed as a U-shaped reflector. The U-shaped director 2, the inverted concave radiator 1, and the U-shaped reflector 3 are arranged along a common axis, and their outer contours can be designed to be consistent or similar, which helps to effectively guide and converge electromagnetic waves in the axial direction, thereby forming a radiation beam with strong directionality. The introduction of director 2 and reflector 3 is key to improving the front-to-back ratio and gain of the antenna structure.

[0037] In this embodiment, the length of reflector 3 is configured to be slightly longer than half a wavelength of the operating frequency band, exhibiting inductive properties, with its induced current lagging behind the induced electromotive force by 90°. Reflector 3 is used to reflect rearward radiated energy to the front, and to superimpose and enhance it with the frontal radiation field.

[0038] Specifically, radiator 1 (an active oscillator) is located a quarter wavelength in front of reflector 3. The induced electromotive force (EMF) of radiator 1 leads the induced EMF of reflector 3 by 90°. Because the oscillator resonates, its EMF is in phase with the current. Therefore, the oscillator current leads the reflector current by 180°, while the magnetic field induced by the reflector current lags the current by 90°. The EMF induced in the oscillator by the induced magnetic field lags the magnetic field itself by 90°. Ultimately, the induced EMF of reflector 3 on radiator 1 is in phase with the induced EMF of radiator 1 itself, and the two are superimposed and enhanced.

[0039] The length of director 2 is slightly shorter than half a wavelength, exhibiting capacitive characteristics, and its induced current leads the induced electromotive force by 90°. Director 2 is used to guide and focus electromagnetic wave energy in front.

[0040] Specifically, director 2 is located a quarter wavelength in front of radiator 1. The induced electromotive force (EMF) of the oscillator lags behind the induced EMF of director 2 by 90°. Because the oscillator resonates, the EMF of radiator 1 is in phase with the current. Therefore, the oscillator current lags behind the director current by 180°, and the magnetic field induced by the director current lags behind the current by 90°. The EMF induced by the induced magnetic field on radiator 1 lags behind the magnetic field itself by 90°. Ultimately, the induced EMF of director 2 on radiator 1 is in phase with the induced EMF of radiator 1 itself, and the two are superimposed and enhanced.

[0041] In this embodiment, by arranging the radiator 1 (active oscillator), the director 2 and the reflector 3 at a spacing of about a quarter wavelength and precisely optimizing their length ratio, the phase relationship of the induced current of the three can satisfy the enhancement conditions of the end-fire array, thereby significantly improving the gain of the antenna structure in the main radiation direction.

[0042] In some other embodiments, the number of directors 2 may not be limited to one layer. By setting multiple layers of directors 2, the antenna structure gain can be further improved while the vertical beamwidth is further compressed, so as to meet the directional readout requirements at longer distances.

[0043] See Figure 1 As shown, furthermore, in order to form a robust and electrically consistent integrated mechanical structure for the radiator 1, director 2, and reflector 3, the antenna structure also includes a tuner 4. Specifically, the tuner 4 is a type I tuner 4.

[0044] Specifically, the Type I tuner 4 serves as the core framework in terms of mechanics, used to coaxially connect and fix the radiator 1, director 2 and reflector 3 along the axial direction, thereby forming a three-dimensional and robust integrated antenna body, which simplifies the antenna assembly process and can also improve the reliability and structural stability of the product in common drop or vibration scenarios of portable devices.

[0045] Furthermore, the three-dimensional structural design can further reduce the space occupied by the antenna structure in the axial direction, thereby further reducing the overall size of the antenna structure. This helps to further reduce the overall size of the equipment while ensuring structural stability and reliability.

[0046] Combination Figures 2 to 4 As shown, Figure 2 The figure shows the gain curve of the antenna structure in simulation software according to one embodiment of this application. Figure 3 The image shows a 3D radiation pattern of the antenna structure in antenna simulation software according to one embodiment of this application. Figure 3 The diagram shows the return loss of the antenna structure in antenna simulation software according to one embodiment of this application.

[0047] In terms of electrical performance, the Type I tuner 4 can be regarded as an equivalent lumped capacitor element. The presence of tuner 4 allows for fine-tuning of the resonant frequency of the entire antenna structure. This characteristic enables the antenna to accurately resonate in the target frequency band even when there are small tolerances in antenna processing or assembly, by adjusting the size of tuner 4.

[0048] More importantly, the combination of radiator 1 and type I tuner 4 is not a simple mechanical connection, but rather constitutes a functionally integrated radiating structure. This integrated radiating structure cleverly integrates multiple functions.

[0049] First, radiator 1 itself, as a half-wave oscillator, provides basic balanced radiation functionality.

[0050] Secondly, the specific connection method and structure of the Type I tuner 4 and radiator 1 together realize the function of an impedance transformer. Specifically, the balanced impedance (approximately 73 ohms) presented by radiator 1 at resonance needs to pass through a quarter-wavelength impedance transformation section to achieve good matching with the 50-ohm single-ended port of the RF front-end standard. The physical structure of the Type I tuner 4 is designed to provide this transformation characteristic.

[0051] Finally, the integrated structure also inherently implements the function of a balun. The balun is used to convert the balanced feed mode of radiator 1 to a single-ended mode matched to the coaxial cable and to suppress common-mode currents that may cause losses and pattern distortion.

[0052] In summary, through the collaborative design of radiator 1 and type I tuner 4, this scheme integrates the three functions that traditionally require discrete components or complex circuits to implement—active oscillator, impedance transformer, and balun—into a simple physical structure.

[0053] This antenna structure can directly present a single-ended feed impedance of approximately 50 ohms, allowing it to be directly connected to the reader's RF module via a single coaxial cable. This eliminates the need for external balun devices, impedance matching circuit boards, or complex power divider networks, reducing insertion loss, improving radiation efficiency, and simplifying peripheral circuit design and overall cost.

[0054] To further enhance the mechanical strength of the antenna structure, especially when used as a stand-alone module or in shock-prone environments, the structure may also include support members 5. Support members 5 are typically two in number, positioned parallel to the Type I tuner 4 on both sides of the antenna structure. Each support member 5 is connected to the reflector 3, radiator 1, and director 2, forming a lateral reinforcement frame.

[0055] The support component 5 effectively prevents the antenna from deforming under external impact, ensuring long-term stability of electrical performance. To provide further protection for the antenna body and facilitate installation, a housing can be installed for the entire antenna structure. The housing can be a two-piece snap-fit ​​structure, secured with clips or screws to firmly encapsulate the antenna body. This snap-fit ​​housing provides both physical protection and facilitates easy disassembly and maintenance of the antenna module.

[0056] In terms of specific size design, to achieve optimal performance in the UHF RFID band, the dimensions of each component can be optimized. For example, the length of reflector 3 can be designed to be between 1.05 and 1.1 times the half-wavelength corresponding to the operating frequency; the length of director 2 can be designed to be between 0.85 and 0.95 times the half-wavelength; and the axial spacing between radiator 1, director 2, and reflector 3 can be set around a quarter-wavelength. These dimensional relationships are key parameters for ensuring high antenna gain and a high front-to-back ratio.

[0057] In the above embodiments, L1 is the length of reflector 3, L2 is the length of director 2, and λ is the wavelength of the center frequency point of the operating frequency band, which is simply referred to as wavelength in this application.

[0058] In some embodiments, based on the antenna structure described above, this application also provides a transceiver device. The transceiver device includes a housing, a circuit module, and the aforementioned antenna structure. The circuit module is disposed within the housing and is used to generate radio frequency signals and perform signal processing. The antenna structure may be disposed within the housing or partially integrated on the surface of the housing, and is electrically connected to the radio frequency port of the circuit module via a feed gap 13.

[0059] Understandably, due to its compact structure, high integration, and excellent performance, this antenna structure is particularly suitable for portable devices with strict space and weight constraints. Therefore, the transceiver's casing can be a handheld casing for easy operation, similar to a smartphone or barcode scanner; or it can be a wearable casing, integrated into work gloves, armbands, or helmets. This allows the technical solution to flexibly adapt to various mobile application scenarios such as warehouse inventory, field inspections, and production line inspections, thus broadening its applicability.

[0060] In summary, the antenna structure and transceiver provided in this application achieve miniaturization, high-gain directional radiation, and simplified 50-ohm single-ended direct feed within a compact structure by using an inverted concave radiator 1 formed by bending a single continuous conductor, combined with a U-shaped director 2 and a U-shaped reflector 3, and using an I-type tuner 4 to achieve mechanical fixation and electrical function integration of the three.

[0061] The antenna structure, as shown in the above embodiments, avoids the complex feeding network of traditional high-gain antennas, reducing losses and costs. Its integrated design also improves reliability and ease of production, thereby extending the read / write distance of portable UHF RFID devices and enhancing the overall performance of the device.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An antenna structure, characterized in that, include: The radiator is constructed as a non-closed ring structure formed by bending a continuous conductor and has a recess; the continuous conductor includes a first free end and a second free end spaced apart, and a feeding gap is formed between the first free end and the second free end, the feeding gap being located at the middle position of the radiator in the width direction. A director is disposed on one side of the radiator; A reflector is disposed on the opposite side of the radiator and the director. and The tuner connects the radiator, the director, and the reflector into a single structure.

2. The antenna structure according to claim 1, characterized in that, The director is configured as a U-shaped director, and the reflector is configured as a U-shaped reflector.

3. The antenna structure according to claim 2, characterized in that, The outer contours of the U-shaped director, the radiator, and the U-shaped reflector are consistent.

4. The antenna structure according to claim 1, characterized in that, The tuner is a Type I tuner, which is used to coaxially connect the radiator, the director, and the reflector, and is equivalent to a capacitor element in the circuit to fine-tune the resonant frequency of the antenna structure.

5. The antenna structure according to claim 4, characterized in that, The radiator and the tuner together constitute an integrated radiating structure, which is configured to simultaneously perform the functions of an active oscillator, an impedance transformer, and a balun.

6. The antenna structure according to claim 2, characterized in that, The reflector satisfies the following relationship: L1 = 1.05λ ~ 1.1λ; The director satisfies the following relationship: L2 = 0.85λ ~ 0.95λ; Where L1 is the length of the reflector, L2 is the length of the director, and λ is the wavelength of the center frequency of the operating frequency band.

7. The antenna structure according to any one of claims 1-6, characterized in that, The antenna structure also includes a support member, which is arranged parallel to the tuner and connected to the reflector, the radiator and the director respectively.

8. The antenna structure according to claim 7, characterized in that, The support member is provided in two parts, one of which is connected to one side of the reflector, the radiator and the director along the width direction, and the other support member is connected to the other side of the reflector, the radiator and the director along the width direction.

9. A transceiver device, characterized in that, The device includes a housing, a circuit module, and an antenna structure as described in any one of claims 1-8, wherein the circuit module is disposed within the housing, and the antenna structure is disposed within the housing or on the surface of the housing and is electrically connected to the circuit module.

10. The transceiver device according to claim 9, characterized in that, The housing may be a handheld housing or a wearable housing.

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