Planar loop antenna and electronic equipment

Abstract

The invention discloses a planar loop antenna and electronic equipment, and relates to the technical field of microwave communication. The first annular radiating body is arranged on the bearing part, a feeding point and a grounding point are arranged on the first annular radiating body, and a first gap is formed in the first annular radiating body and located between the feeding point and the grounding point; at least one second annular radiator; according to the invention, the first annular radiator and the at least one second annular radiator are arranged on the bearing member in an internal and external surrounding layout mode, and the gaps are arranged between the radiators to form a multi-stage electromagnetic coupling path, so that the structure can effectively inhibit the parasitic effect introduced by peripheral metal elements, significantly reduce the risk of frequency deviation, and improve the reliability of the antenna. The antenna is ensured to maintain stable impedance characteristic and radiation performance in a complex electromagnetic environment in which a mainboard, a battery and the like are densely arranged.

Description

Technical Field

[0001] This application relates to the field of microwave communication technology, and in particular to a planar loop antenna and electronic device. Background Technology

[0002] With the widespread application of Bluetooth technology in consumer electronics products such as TWS earphones, smart wearable devices, and IoT sensors, device structures are showing a clear trend towards thinner and smaller designs. As a key component of wireless communication systems, antenna design needs to adapt to the extremely limited space within the device while simultaneously ensuring low power consumption and stable radiation performance. This presents antenna design with a severe challenge in achieving high performance in a high-density integration environment.

[0003] In existing technologies, antenna designs mainly employ traditional structural forms such as dipole antennas and inverted-F antennas. A dipole antenna consists of two symmetrically distributed straight conductor elements, with signal excitation achieved through balanced feeding. An inverted-F antenna comprises three core parts: a radiating element, a short-circuited stub, and a feed point, forming a unique L-shaped structure that offers the advantage of grounding shielding. To achieve the gain and radiation efficiency required for communication, these traditional antenna structures typically require relatively large physical dimensions.

[0004] With increasingly compact internal spaces in consumer electronics, antennas are surrounded by densely packed motherboards, batteries, and other metal components, creating a complex electromagnetic environment. In such environments, the radiation characteristics of traditional antenna structures are easily affected by electromagnetic coupling from surrounding components, resulting in shifts in operating frequency and changes in impedance matching. This leads to insufficient anti-interference capability of traditional antennas in confined spaces, impacting the stability and reliability of communication connections. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a planar loop antenna and electronic device to solve the problem of insufficient anti-interference capability of traditional antennas in compact spaces.

[0006] In a first aspect, embodiments of this application provide a planar loop antenna, comprising: a carrier; a first loop radiator disposed on the carrier, the first loop radiator having a feed point and a ground point, and a first gap disposed on the first loop radiator and located between the feed point and the ground point; at least one second loop radiator disposed on the carrier and surrounding the outside of the first loop radiator, and a second gap disposed between the first loop radiator and the second loop radiator; when electrical energy is introduced through the feed point, the first loop radiator and the second loop radiator are electromagnetically coupled through the second gap to form an electromagnetic radiation field.

[0007] In one feasible implementation, the first annular radiator and the second annular radiator have the same shape.

[0008] In one feasible implementation, the first annular radiator and the second annular radiator are in the shape of a circular ring, an elliptical ring, or a rectangular ring.

[0009] In one feasible implementation, the power supply method of the power supply point is probe power supply or spring-loaded power supply.

[0010] In one feasible implementation, the operating frequency band of the loop planar antenna is 2400-2483.5MHz.

[0011] In one feasible implementation, the support member is provided with a plurality of annular grooves, and the first annular radiator and the second annular radiator are both disposed in the annular grooves.

[0012] In one feasible implementation, the carrier is made of plastic.

[0013] In one feasible implementation, the second annular radiator is a passive parasitic element.

[0014] In one feasible implementation, a third gap is provided between adjacent second annular radiators.

[0015] Secondly, embodiments of this application provide an electronic device, including a planar loop antenna as described in any one of the first aspects.

[0016] This invention provides a planar loop antenna and electronic device, which have the following advantages: This invention arranges a first annular radiator and at least one second annular radiator in an inner-outer ring arrangement on a carrier, with gaps between the radiators to form a multi-level electromagnetic coupling path. This structure can effectively suppress parasitic effects introduced by surrounding metal components, significantly reduce the risk of frequency shift, and ensure that the antenna maintains stable impedance characteristics and radiation performance in complex electromagnetic environments with densely packed motherboards, batteries, and other components. At the same time, the annular radiator structure has the characteristic of high space utilization. By highly integrating multiple annular radiators on the carrier, the physical size of the antenna can be reduced, thereby optimizing the overall performance of the antenna and miniaturizing the physical structure. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the implementation of the invention and, together with the description, serve to explain the principles of the embodiments of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 This is a schematic diagram of the structure of a planar loop antenna provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a planar loop antenna in which the first and second loop radiators are square rings, according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a planar loop antenna in which the first loop radiator and the second loop radiator are rectangular rings, according to an embodiment of the present invention. Figure 4 This invention provides a schematic diagram of the structure of a planar loop antenna in which the first and second loop radiators are elliptical rings, according to an embodiment of the invention. Figure 5 This is a schematic diagram of the structure of a first ring radiator and two second ring radiators of a planar ring antenna provided in an embodiment of the present invention; Figure 6 The return loss curve provided for the embodiments of the present invention; Figure 7 Gain curves provided for embodiments of the present invention; Figure 8 The radiation efficiency curve is provided for an embodiment of the present invention.

[0019] In the figure: 1. First annular radiator; 11. Feed point; 12. Grounding point; 13. First gap; 2. Second annular radiator; 3. Supporting component; 31. Annular groove; 4. Second gap; 5. Third gap. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0022] Furthermore, in this application, directional terms such as "upper," "lower," "inner," and "outer" are defined relative to the indicated placement of the components in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the placement of the components in the accompanying drawings.

[0023] In existing technologies, antenna designs mainly employ traditional structural forms such as dipole antennas and inverted-F antennas. A dipole antenna consists of two symmetrically distributed straight conductor elements, with signal excitation achieved through balanced feeding. An inverted-F antenna comprises three core parts: a radiating element, a short-circuited stub, and a feed point, forming a unique L-shaped structure that offers the advantage of grounding shielding. To achieve the gain and radiation efficiency required for communication, these traditional antenna structures typically require relatively large physical dimensions.

[0024] With increasingly compact internal spaces in consumer electronics, antennas are surrounded by densely packed motherboards, batteries, and other metal components, creating a complex electromagnetic environment. In such environments, the radiation characteristics of traditional antenna structures are easily affected by electromagnetic coupling from surrounding components, resulting in shifts in operating frequency and changes in impedance matching. This leads to insufficient anti-interference capability of traditional antennas in confined spaces, impacting the stability and reliability of communication connections.

[0025] In addition, traditional antenna structures typically require a large physical size to achieve good gain and efficiency, which contradicts the current trend of ultra-compact design pursued by consumer electronics products, making it difficult for them to meet the compact design requirements of consumer electronics products.

[0026] This invention provides a planar loop antenna and electronic device to solve the problems of insufficient anti-interference capability of traditional antennas in compact spaces and large physical size.

[0027] The embodiments of this application will now be described with reference to the accompanying drawings.

[0028] This application provides a planar loop antenna; please refer to [link / reference]. Figure 1 , Figure 1A schematic diagram of a planar loop antenna provided in an embodiment of the present invention includes: a carrier 3, a first loop radiator 1, and at least one second loop radiator 2. The carrier 3 can be made of plastic, specifically, it can be a plastic support. The first loop radiator 1 and the second loop radiator 2 are both metal devices. The first loop radiator 1 is disposed on the carrier 3, and the second loop radiator 2 is disposed on the carrier 3 and surrounds the outside of the first loop radiator 1. When there is only one second loop radiator 2, the first loop radiator 1 and the second loop radiator 2 form a double-ring structure. When there are two or more second loop radiators 2, the first loop radiator 1 and multiple second loop radiators 2 form a multi-ring structure. The first loop radiator 1 and the second loop radiator 2 are integrated on the plastic carrier 3 in an inner and outer loop arrangement. The plastic carrier 3 not only provides stable mechanical support and reliable electrical insulation for the first loop radiator 1 and the second loop radiator 2, but its dielectric properties also help to achieve miniaturization of the antenna, which can effectively reduce the overall physical size of the antenna. This compact design saves internal space, making it particularly suitable for installation in modern portable electronic devices where space is limited, enabling high performance and high reliability within a confined space.

[0029] The first annular radiator 1 has a feed point 11 and a ground point 12, and a first gap 13 is provided on the first annular radiator 1 between the feed point 11 and the ground point 12. When a high-frequency current is introduced into the first annular radiator 1 through the feed point 11, since the loop circumference of the first annular radiator 1 is smaller than the operating wavelength (for example, for the 2.4 GHz band, its loop circumference is much smaller than half the wavelength of that band, 125 mm), the alternating magnetic field formed by the high-frequency current along the first annular radiator 1 plays a dominant role in the radiation. According to electromagnetic field theory, a small loop carrying a high-frequency current can be equivalent to a magnetic dipole, and its impedance characteristics are significant inductive reactance. Therefore, the first annular radiator 1 can be equivalent to an inductor. The inductance value of this equivalent inductance mainly depends on the physical structural parameters of the loop: the larger the effective area enclosed by the loop, the larger its equivalent inductance value; under the single-loop structure condition, the loop conductor path length (i.e., the loop circumference) is positively correlated with the equivalent inductance value.

[0030] The feed point 11, ground point 12, and the first gap 13 between them, all located on the first annular radiator 1, constitute the basic resonant structure of the antenna. The first gap 13, in its equivalent circuit, acts as a series capacitor, forming an LC resonant circuit together with the equivalent inductance of the first annular radiator 1. The resonant characteristics of this circuit determine the fundamental operating frequency of the antenna. By adjusting the width of the first gap 13, its equivalent capacitance value can be changed, thereby achieving fine-tuning of the antenna's resonant frequency and optimization of impedance matching.

[0031] A second gap 4 is provided between the first ring radiator 1 and the second ring radiator 2. The second ring radiator 2 is a passive parasitic element, arranged in a surrounding manner outside the first ring radiator 1 to form a dual-ring coupled cooperative working structure. Through the coupling effect between the second ring radiator 2 and the first ring radiator 1, multiple resonant modes can be excited at adjacent frequency points. The superposition of multiple resonant modes can effectively expand the impedance bandwidth of the antenna, enabling it to fully cover the target communication frequency band, such as the 2400-2483.5MHz band required for Bluetooth. The second ring radiator 2 can optimize the near-field distribution of the antenna, guiding energy to radiate more effectively into space, thereby improving the overall gain and radiation efficiency of the antenna. In addition, adjusting the size of the second gap 4 can easily and quickly optimize the antenna impedance matching. At the same time, this adjustment can change the energy distribution and radiation efficiency in the dual-ring structure, thereby improving the final gain level of the antenna.

[0032] Specifically, in the planar loop antenna structure, the second gap 4 between the first loop radiator 1 and the second loop radiator 2 acts as a capacitive coupling element in the equivalent circuit. The first loop radiator 1 and the second loop radiator 2 on both sides of the second gap 4 form the two plates of a capacitor, with the air or plastic dielectric between them forming an insulating layer. Under high-frequency operation, electromagnetic energy is coupled and transmitted through the electric field of the second gap 4, forming typical capacitive coupling characteristics. The equivalent capacitance value of the second gap 4 mainly depends on the following structural parameters: the gap distance between the two loop radiators, the relative area of ​​adjacent conductors, and the characteristics of the dielectric material between them. By precisely adjusting the structural parameters, its equivalent capacitance value can be changed, thereby controlling the coupling strength and phase relationship between the two radiators. This controllable capacitive coupling mechanism allows the antenna to achieve precise tuning of the resonant frequency and optimization of radiation performance while maintaining a compact structure, effectively improving the antenna's impedance matching characteristics and operational stability. The second gap 4 and the first gap 13 work synergistically in the circuit, jointly forming a multi-level coupling network, providing the antenna with more flexible frequency control capabilities and better environmental adaptability.

[0033] When electrical energy is introduced through feed point 11, the first ring radiator 1 and the second ring radiator 2 are electromagnetically coupled through the second gap 4 to form an electromagnetic radiation field. When a high-frequency signal is introduced into the first ring radiator 1 through feed point 11, the first radiator, after being energized, is equivalent to an inductive element and can establish a time-varying electromagnetic field. This electromagnetic energy is coupled and transmitted through the second gap 4 between the first ring radiator 1 and the second ring radiator 2. This gap structure behaves as a capacitive element in the equivalent circuit. Thus, the equivalent inductance of the first ring radiator 1 and the equivalent capacitance of the gap structure together constitute an electromagnetic coupling network, realizing the efficient transfer and redistribution of energy between the two radiators. In this process, the first ring radiator 1, as the main radiating unit, generates the basic radiation field, and the second ring radiator 2, as a parasitic unit, generates a secondary radiation field under electromagnetic coupling excitation. The two radiation fields are vector superimposed in space. By reasonably designing the relative size, spacing, and gap parameters of the two ring radiators, the synthesized radiation field pattern can be optimized, making the radiated energy more concentrated in a specific direction, thereby significantly improving the directivity and overall gain of the antenna. Meanwhile, this dual-ring coupling structure forms a self-stabilizing mechanism for the electromagnetic field. When parasitic parameters are introduced by surrounding metal components, the coupling path between the two rings can compensate for the resulting impedance changes to a certain extent, keeping the antenna's operating frequency stable and reducing the risk of frequency drift. This characteristic enables the antenna to maintain a stable impedance matching state and radiation performance even in complex system environments, significantly improving product reliability and environmental adaptability.

[0034] In some embodiments, please refer to Figure 2 , Figure 3 and Figure 4 , Figure 2 This is a schematic diagram of the structure of a planar loop antenna provided in an embodiment of the present invention, where the first and second loop radiators are square rings. Figure 3 This is a schematic diagram of the structure of a planar loop antenna provided in an embodiment of the present invention, where the first and second loop radiators are rectangular rings. Figure 4This is a schematic diagram of the structure of a planar loop antenna provided in an embodiment of the present invention, where the first loop radiator 1 and the second loop radiator 2 are elliptical rings. The first loop radiator 1 and the second loop radiator 2 have the same shape. The first loop radiator 1 and the second loop radiator 2 can be circular, elliptical, or rectangular rings. The consistent ring structure of the first loop radiator 1 and the second loop radiator 2 can ensure the uniformity and predictability of electromagnetic field coupling between the two radiators, which is beneficial to forming a stable and controllable radiation mode. When the first loop radiator 1 and the second loop radiator 2 are circular rings, the antenna can obtain approximately omnidirectional radiation characteristics on the horizontal plane. When they are elliptical or rectangular rings, radiation enhancement can be achieved in a specific direction, thereby flexibly adapting to different coverage requirements. This consistent shape design can simplify the antenna tuning process and maximize the use of the limited space inside the portable electronic device through a regular geometric layout, thereby providing greater flexibility for the internal structure design of the whole device while ensuring the antenna radiation performance.

[0035] Specifically, when both the first ring radiator 1 and the second ring radiator 2 are circular ring structures, the antenna can generate approximately omnidirectional radiation characteristics in the horizontal plane. This characteristic stems from the inherent rotational symmetry of the circular structure. When a high-frequency current propagates uniformly along the ring conductor, it forms a uniformly distributed radiation field pattern in the horizontal plane. The first ring radiator 1, as the main radiating unit, maintains an equal amplitude distribution of the magnetic field component generated by its ring current in all directions of the horizontal plane. The second ring radiator 2, as a parasitic unit, is excited through gap coupling, and its ring current, together with the current of the main radiator, further balances the field strength distribution in the horizontal plane. This dual-ring cooperative working mechanism effectively compensates for the directional fluctuations that may exist in a single ring structure, ensuring that the synthesized electromagnetic wave maintains a stable radiation intensity within a 360-degree horizontal range. This omnidirectional radiation characteristic ensures that the antenna can maintain a reliable signal connection even in application scenarios where communication terminals are randomly oriented, making it particularly suitable for short-range wireless communication systems such as Bluetooth and ZigBee that require omnidirectional coverage. By optimizing the spacing and coupling strength of the two rings, the overall gain and radiation efficiency of the antenna can be further improved while maintaining omnidirectionality.

[0036] When the first ring radiator 1 and the second ring radiator 2 adopt an elliptical or rectangular ring structure, the antenna can achieve radiation enhancement in a specific direction. This characteristic stems from the directional modulation of surface current distribution by the non-circular ring structure. In the elliptical ring structure, the conductor path along the major axis is longer, resulting in a more concentrated current density in this region and a stronger equivalent radiation source. Simultaneously, the change in ring curvature alters the phase relationship of electromagnetic wave superposition, causing the radiation fields at both ends of the major axis to superimpose in phase, ultimately resulting in radiation enhancement in the direction perpendicular to the major axis. The rectangular ring structure generates a more significant edge radiation effect through its straight-side conductors; the current discontinuity at the four corners excites a stronger electric field distribution. When the currents on the long-side conductor of the rectangle are in phase, a stronger radiation beam is constructed in the direction perpendicular to the long side. By adjusting the ratio of the major and minor axes of the elliptical ring or the length and width of the rectangular ring, the antenna's radiation directivity and beamwidth can be precisely controlled. This directional enhancement characteristic allows the antenna to be optimized for specific coverage areas, making it valuable for applications requiring directional communication, such as smart homes and industrial sensor networks.

[0037] In some embodiments, the feeding method of the feeding point 11 is probe feeding or spring-loaded feeding. These two feeding methods can make the antenna suitable for different equipment structures and assembly process requirements. They are easy to directly solder to the printed circuit board (PCB) and also suitable for reliable connection to the motherboard through contact springs. Both feeding methods can ensure efficient transmission of radio frequency signals, while facilitating the manufacturability and testability of the whole machine mass production, effectively reducing assembly complexity and production costs.

[0038] In some embodiments, the operating frequency band of the loop planar antenna is 2400-2483.5MHz. This frequency band configuration allows the antenna to fully cover the operating frequency bands of mainstream short-range wireless communication protocols such as Bluetooth, Wi-Fi, and ZigBee, ensuring compatibility with wireless communication modules of various IoT devices, portable electronic products, and smart home devices. It also allows the antenna to exhibit stable impedance characteristics and uniform radiation efficiency within this frequency band, supporting high-efficiency data transmission to meet the performance requirements of modern wireless communication antennas.

[0039] In some embodiments, the carrier 3 is provided with a plurality of annular grooves 31, and the first annular radiator 1 and the second annular radiator 2 are both disposed in the annular grooves 31. This allows the carrier 3 to provide precise positioning and stable support for the first annular radiator 1 and the second annular radiator 2, ensuring that the relative positions between the radiators remain consistent, thereby guaranteeing the stability of antenna performance and the consistency of the product. In addition, this embedded layout of the first annular radiator 1 and the second annular radiator disposed in the annular grooves 31 can reduce the overall profile height of the antenna, thereby reducing the space occupied inside the device.

[0040] In some embodiments, please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of a planar loop antenna, including a first loop radiator and two second loop radiators, according to an embodiment of the present invention. A third gap 5 is provided between adjacent second loop radiators 2. This gap structure establishes a controllable capacitive coupling path between adjacent parasitic elements. When a second loop radiator 2 is excited by the electromagnetic field of the first loop radiator 1, an induced current is generated on its surface. The third gap 5 between adjacent second loop radiators 2 will exhibit capacitive coupling characteristics. By adjusting the size of this gap, its equivalent capacitance value can be changed, thereby precisely controlling the energy exchange and phase distribution between each second loop radiator 2. The capacitive coupling introduced by the third gap 5 can adjust the current amplitude and phase on each parasitic element, thereby optimizing the overall current distribution of the antenna. It can introduce additional coupled resonant modes near the main resonant frequency, effectively expanding the antenna's operating bandwidth. In addition, it can improve the antenna's radiation pattern and enhance its directivity or omnidirectional performance. This design of introducing gap coupling in the parasitic element array provides an effective means to achieve fine control of radiation characteristics while maintaining the compactness of the antenna structure, enhancing the flexibility and environmental adaptability of antenna performance design.

[0041] Please see Figure 6 , Figure 6 The return loss curve provided in this embodiment of the invention has a -10dB matching bandwidth that can cover 2.4GHz-2.5GHz, completely covering the target frequency band. The return loss curve is smooth and without drastic fluctuations throughout the entire operating frequency band, especially showing excellent performance near the core frequency point. This indicates that the antenna has stable impedance matching, low energy reflection, and high radiation efficiency throughout the entire operation process.

[0042] Please see Figure 7 , Figure 7 The gain curve provided in this embodiment of the invention shows that the antenna gain is stable above 1 dBi throughout the entire operating frequency band from 2400 MHz to 2500 MHz. This gain characteristic indicates that the present invention can maintain wide bandwidth characteristics while providing effective radiation performance. The stable gain response ensures the consistency of signal radiation intensity within the operating frequency band, avoids communication quality fluctuations caused by frequency changes, and can fully meet the needs of typical 2.4 GHz frequency band wireless communication applications such as Bluetooth and Wi-Fi.

[0043] Please see Figure 8 , Figure 8The radiation efficiency curve provided in this embodiment of the invention shows that the antenna's radiation efficiency is above 30% in the operating frequency band of 2400MHz to 2500MHz, and can reach about 35% in the center frequency band. This radiation efficiency characteristic indicates that the antenna structure can effectively convert most of the input energy into electromagnetic wave radiation with low energy loss. In the operating frequency band, the radiation efficiency curve changes smoothly without significant drop, indicating that the antenna can maintain stable radiation performance throughout the entire bandwidth.

[0044] This application provides an electronic device, including a planar loop antenna as described above; the electronic device described in this embodiment can be an electronic product such as a TWS earphone, a smart wearable device, or an IoT sensor.

[0045] This invention arranges a first annular radiator 1 and at least one second annular radiator 2 in an inner-outer ring arrangement on a carrier 3, with gaps between the radiators to form a multi-level electromagnetic coupling path. This structure can effectively suppress parasitic effects introduced by surrounding metal components, significantly reduce the risk of frequency shift, and ensure that the antenna maintains stable impedance characteristics and radiation performance in complex electromagnetic environments with densely packed motherboards, batteries, and other components. At the same time, the annular radiator structure has the characteristic of high space utilization. By highly integrating multiple annular radiators on the carrier 3, the physical size of the antenna can be reduced, thereby optimizing the overall performance of the antenna and miniaturizing the physical structure.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A planar loop antenna, characterized in that, include: Supporting component (3); A first annular radiator (1) is provided on the support member (3). The first annular radiator (1) is provided with a power supply point (11) and a grounding point (12). A first gap (13) is provided on the first annular radiator (1) and located between the power supply point (11) and the grounding point (12). At least one second annular radiator (2) is provided on the support member (3) and surrounds the outside of the first annular radiator (1), and a second gap (4) is provided between the first annular radiator (1) and the second annular radiator (2); When electrical energy is introduced through the feed point (11), the first annular radiator (1) and the second annular radiator (2) are electromagnetically coupled through the second gap (4) to form an electromagnetic radiation field.

2. The planar loop antenna according to claim 1, characterized in that, The first annular radiator (1) has the same shape as the second annular radiator (2).

3. A planar loop antenna according to claim 2, characterized in that, The first annular radiator (1) and the second annular radiator (2) are circular, elliptical, or rectangular rings.

4. A planar loop antenna according to claim 1, characterized in that, The power supply point (11) is powered by a probe or a spring-loaded foot.

5. A planar loop antenna according to claim 1, characterized in that, The operating frequency band of the ring-shaped planar antenna is 2400-2483.5MHz.

6. A planar loop antenna according to claim 1, characterized in that, The support member (3) is provided with a plurality of annular grooves (31), and the first annular radiator (1) and the second annular radiator (2) are both provided in the annular grooves (31).

7. A planar loop antenna according to claim 1, characterized in that, The support component (3) is made of plastic.

8. A planar loop antenna according to claim 1, characterized in that, The second annular radiator (2) is a passive parasitic element.

9. A planar loop antenna according to claim 1, characterized in that, A third gap (5) is provided between adjacent second annular radiators (2).

10. An electronic device, characterized in that, Includes a planar loop antenna as described in any one of claims 1-9.

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