Circularly polarized antenna and wearable device

Abstract

The utility model relates to the technical field of antennas, in particular to a circularly polarized antenna and a wearable device. The circularly polarized antenna comprises a grounding plate which is provided with a feed port; the feed body is provided with a first coupling end and a second coupling end, and the first coupling end is electrically connected with the feed port; one end of the first radiator is connected with the second coupling end, and the other end of the first radiator is connected with the grounding plate; one end of the second radiating body is connected with the second coupling end, the other end of the second radiating body is separated from the grounding plate, and the second radiating body and the first radiating body are located on the two sides of the feed body respectively in the circumferential direction of the grounding plate. The first radiating body is grounded, so that when the circularly polarized antenna works, the current intensity of the grounding end of the first radiating body is relatively high, that is, current exists on the antenna branch knot and certain current exists on the grounding plate, and the current distribution on the left side and the right side is relatively uniform, so that a circularly polarized directional diagram is relatively symmetrical and stable; and the circular polarization effect of the circular polarization antenna is improved.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and more particularly to a circularly polarized antenna and wearable device. Background Technology

[0002] In wireless communication systems, antennas are key components for signal transmission and reception. With the development of wireless communication technology, applications such as wireless data communication and acquisition are becoming increasingly widespread. Wireless transceiver devices are trending towards miniaturization, thus circularly polarized antennas are receiving more and more research and application.

[0003] Compared to linearly polarized antennas, circularly polarized antennas can receive not only circularly polarized electromagnetic waves of the same rotation direction, but also electromagnetic waves of arbitrary linear polarization. Furthermore, the electromagnetic waves radiated by these antennas can be received by either circularly polarized antennas of the same rotation direction or antennas of arbitrary linear polarization. However, the circular polarization effect of current circularly polarized antennas is not ideal. Utility Model Content

[0004] This application discloses a circularly polarized antenna and a wearable device, which can solve the problem of poor circular polarization effect of current circularly polarized antennas.

[0005] To achieve the above objectives, in a first aspect, embodiments of this application disclose a circularly polarized antenna, comprising:

[0006] Grounding plate with power supply port;

[0007] The power supply has a first coupling end and a second coupling end, wherein the first coupling end is electrically connected to the power supply port.

[0008] A first radiator, one end of which is connected to the second coupling end, and the other end of which is connected to the ground plane;

[0009] The second radiator has one end connected to the second coupling end and the other end separated from the ground plane. The second radiator and the first radiator are located on both sides of the feed body along the circumference of the ground plane.

[0010] When the first radiator and the second radiator resonate in the operating frequency band, the electrical signals on the first radiator and the second radiator satisfy the condition that the resonance amplitude is equal and the resonance phase is 90 degrees apart.

[0011] In one alternative embodiment, the first radiator includes a first part and a second part connected together, the end of the first part away from the second part being connected to a second coupling end, the end of the second part away from the first part being connected to the ground plane, and the first part being parallel to the ground plane.

[0012] In one alternative embodiment, the second part is perpendicular to the ground plane.

[0013] In one optional embodiment, the extension length of the second part is L1, the extension length of the feed body is L2, the extension length of the first part is L3, and (L1+L2)<(1 / 4)L3.

[0014] In one optional embodiment, the ground plane has a first edge and a second edge disposed adjacent to each other, the first part includes a first segment and a second segment connected together, the end of the first segment opposite to the second segment is connected to the second part, and the end of the second segment opposite to the first segment is connected to the second coupling end;

[0015] The first segment is parallel to the first edge, and the second segment is parallel to the second edge.

[0016] In one optional embodiment, the ground plane has a circular cross-sectional shape, and both the first part and the second radiator have an arc-shaped structure, and the first part and the second radiator are concentrically arranged.

[0017] In one alternative embodiment, the ground plane has a first edge and a third edge disposed opposite to each other, the end of the first radiator connected to the ground plane is close to the first edge, and the power supply port is close to the third edge.

[0018] In one optional embodiment, the sum of the extension lengths of the first radiator and the feeder is L4, and the sum of the extension lengths of the second radiator and the feeder is L5, where 0.23 ≤ (L5 / L4) ≤ 0.4.

[0019] In one optional embodiment, the operating wavelength of the circularly polarized antenna is λ, where L4 > 0.5λ and L5 < 0.25λ.

[0020] In an alternative embodiment, L4 = (0.6~0.7)λ, L5 = (0.20~0.24)λ.

[0021] In one alternative embodiment, L4 = 114–133 mm and L5 = 38–46 mm.

[0022] Secondly, this application provides a wearable device including the circularly polarized antenna described in any of the above embodiments.

[0023] Compared with related technologies, the beneficial effects of this application are:

[0024] In this application, the circularly polarized antenna includes a ground plane, a feed element, a first radiator, and a second radiator. The first coupling end of the feed element is connected to the feed port on the ground plane. The two ends of the first radiator are respectively connected to the second coupling end of the feed element and the ground plane. The second radiator is connected to the second coupling end. When the first and second radiators resonate in the operating frequency band, the electrical signals on the first and second radiators satisfy the condition that the resonance amplitudes are equal and the resonance phases differ by 90 degrees, thus satisfying the circular polarization characteristics. Since the grounding end of the first radiator, which is far from the feed element, is connected to the ground plane, the first radiator is grounded. Furthermore, when the circularly polarized antenna is working, the current intensity at the grounding end of the first radiator is relatively large. This means that not only are there currents in the antenna branches (the first and second radiators), but there is also a certain current on the ground plane, and the current distribution on the left and right sides is relatively uniform, making the circular polarization pattern more symmetrical and stable, thereby improving the circular polarization effect of the circularly polarized antenna. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a current distribution diagram on the ground plane when the current circularly polarized antenna is in operation;

[0027] Figure 2 This is a schematic diagram of a circularly polarized antenna disclosed in an embodiment of this application;

[0028] Figure 3 This is a schematic diagram of the structure of a circularly polarized antenna disclosed in another embodiment of this application;

[0029] Figure 4 This is a schematic diagram of the structure of a circularly polarized antenna disclosed in another embodiment of this application;

[0030] Figure 5 This is a current distribution diagram on the ground plane of the circularly polarized antenna disclosed in the embodiments of this application during operation;

[0031] Figure 6 The reflection coefficient curve of the circularly polarized antenna disclosed in the embodiments of this application in the operating frequency band;

[0032] Figure 7 The axial ratio curve of the circularly polarized antenna disclosed in the embodiments of this application in the operating frequency band;

[0033] Figure 8 The axial ratio curve of the circularly polarized antenna disclosed in the embodiments of this application in the operating frequency band is shown.

[0034] Figure 9 The actual right-hand circular polarization gain curve of the circularly polarized antenna disclosed in the embodiments of this application in the operating frequency band;

[0035] Figure 10 This is the 3D axial ratio radiation pattern of the circularly polarized antenna disclosed in the embodiments of this application in the operating frequency band;

[0036] Figure 11 This is a 3D right-hand circularly polarized actual gain pattern of the circularly polarized antenna disclosed in the embodiments of this application in the operating frequency band.

[0037] Explanation of reference numerals in the attached figures:

[0038] 100. Grounding; 101. First edge; 102. Second edge; 103. Third edge;

[0039] 200. Feeder;

[0040] 300. First radiator; 310. First part; 311. First section; 312. Second section; 320. Second part;

[0041] 400. Second radiator. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0044] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0045] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0046] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0047] In wireless communication systems, antennas are key components for signal transmission and reception. With the development of wireless communication technology, applications such as wireless data communication and acquisition are becoming increasingly widespread. Wireless transceiver devices are trending towards miniaturization, thus circularly polarized antennas are receiving more and more research and application.

[0048] Compared to linearly polarized antennas, circularly polarized antennas can receive not only circularly polarized electromagnetic waves of the same rotation direction, but also electromagnetic waves of arbitrary linear polarization, and the electromagnetic waves they radiate can be received by circularly polarized antennas of the same rotation direction or antennas of arbitrary linear polarization.

[0049] However, the current circular polarization effect of circularly polarized antennas is not ideal. For example, patent publication number CN111490343A discloses a monopole circularly polarized positioning antenna. This positioning antenna includes a ground plane 100, a feed section, a first radiating arm, and a second radiating arm. The ground plane 100 has a feed terminal, and one end of the feed section is electrically connected to the feed terminal. The first and second radiating arms are both connected to the other end of the feed section. When the monopole antenna is fed and operates in its operating frequency band, the electrical signal resonance amplitudes on the two radiating arms are equal, and the phase difference of the resonance is 90°, satisfying the characteristics of circular polarization of the antenna. The inventors discovered that neither the first nor the second radiating arm is connected to the ground plane 100, that is, neither the first nor the second radiating arm is grounded. Therefore, when the monopole antenna is working, the current is mainly concentrated on the antenna stubs (the first and second radiating arms), and the current on the ground plane 100 is very weak, with the current concentrated on the right side (see [link to relevant documentation]). Figure 1 This causes asymmetrical current distribution, resulting in an asymmetrical and unstable radiation pattern. This explains why the circularly polarized beam of CN111490343A is deflected to theta-50°, and why the beam width of beams with an axial ratio less than or equal to 3dB is only about 50° (see CN111490343A). Figure 3 This obviously leads to poor circular polarization performance of the circularly polarized antenna.

[0050] The circularly polarized antenna and wearable device provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0051] like Figure 2 As shown in the figure, this application discloses a circularly polarized antenna, which can be a single-frequency circularly polarized antenna, including:

[0052] Ground plane 100 has a power supply port. Ground plane 100 can be made of a dielectric substrate, such as a PCB (Printed Circuit Board).

[0053] The power supply 200 has a first coupling end and a second coupling end. The first coupling end is electrically connected to the power supply port. For example, the power supply 200 can be perpendicular to the ground plane 100 or inclined relative to the ground plane 100.

[0054] The first radiator 300 has one end connected to the second coupling end and the other end connected to the ground plane 100. That is, the ground plane 100, the feed body 200 and the first radiator 300 form a ring structure. When the circularly polarized antenna is excited based on the feed body 200, the ground plane 100, the feed body 200 and the first radiator 300 constitute a "ring antenna".

[0055] The second radiator 400 has one end connected to the second coupling terminal and the other end separated from the ground plane 100. That is, the end of the second radiator 400 furthest from the second coupling terminal is not grounded. The second radiator 400 and the first radiator 300 are located on opposite sides of the feed body 200 along the circumference of the ground plane 100. Specifically, when the circularly polarized antenna is excited based on the feed body 200, the feed body 200 and the second radiator 400 form an "inverted L-shaped antenna". For example, the second radiator 400 and the first radiator 300 can be distributed sequentially along a first clockwise direction or in the opposite direction. Here, the first clockwise direction can be either clockwise or counterclockwise. The combination of a loop antenna and an inverted L-shaped antenna enables the circularly polarized antenna to achieve circular polarization over a large angle range.

[0056] When the first radiator 300 and the second radiator 400 resonate in the operating frequency band, which can be the GPS (Global Positioning System) L1 band 1575.42±1.023MHz or the L5 band 1176.45±1.023MHz, the electrical signals on the first radiator 300 and the second radiator 400 satisfy the condition that the resonance amplitude is equal and the resonance phase is 90 degrees apart, thus satisfying the circular polarization characteristics.

[0057] In this application, the circularly polarized antenna includes a ground plane 100, a feed element 200, a first radiator 300, and a second radiator 400. The first coupling end of the feed element 200 is connected to the feed port on the ground plane 100. The two ends of the first radiator 300 are respectively connected to the second coupling end of the feed element 200 and the ground plane 100. The second radiator 400 is connected to the second coupling end. When the first radiator 300 and the second radiator 400 resonate in the operating frequency band, the electrical signals on the first radiator 300 and the second radiator 400 satisfy the condition that the resonance amplitude is equal and the resonance phase differs by 90 degrees, thereby satisfying the circular polarization characteristics. Since the grounding terminal of the first radiator 300, which is furthest from the feed body 200, is connected to the ground plane 100, meaning the first radiator 300 is grounded, and the current intensity at the grounding terminal of the first radiator 300 is relatively large when the circularly polarized antenna is working, that is, there is current not only in the antenna stubs (first radiator 300 and second radiator 400), but also in the ground plane 100, and the current distribution on the left and right sides is relatively uniform (see [reference]). Figure 5 This makes the circular polarization pattern more symmetrical and stable, thereby improving the circular polarization effect of the circular polarization antenna.

[0058] In one alternative embodiment, please refer to Figure 3 The first radiator 300 includes a first part 310 and a second part 320 connected together. The end of the first part 310 away from the second part 320 is connected to a second coupling end, and the end of the second part 320 away from the first part 310 is connected to a ground plane 100. The first part 310 is parallel to the ground plane 100.

[0059] In this embodiment, the first radiator 300 includes a first part 310 and a second part 320 connected to each other. The first part 310 is parallel to the ground plane 100, increasing the interaction area and coupling degree between the first radiator 300 and the ground plane 100. The second part 320 is connected to the ground plane 100, thereby providing an electrical connection between the first radiator 300 and the ground plane 100, ensuring the integrity of the current loop. The first part 310 and the second part 320 work together to make the current distribution on the first radiator 300 more uniform and smooth, reducing current loss and reflection, and greatly improving the radiation efficiency of the circularly polarized antenna. Of course, the first part 310 can also be tilted relative to the ground plane 100, and this application does not limit this.

[0060] In one alternative embodiment, please continue to refer to Figure 3 The second part 320 is perpendicular to the ground plane 100, that is, the second part 320 is perpendicular to the first part 310.

[0061] In this embodiment, the second part 320, being perpendicular to the ground plane 100, enables more efficient current conduction in the direction perpendicular to the ground plane 100, thereby enhancing the radiation component of the circularly polarized antenna in the direction perpendicular to the ground plane 100. Furthermore, the second part 320, perpendicular to the ground plane 100, ensures that the current flows perpendicular to the ground plane 100, reducing stray current in the horizontal direction and thus reducing stray radiation in the horizontal direction. This reduces interference with other electronic devices in the same plane, improving the electromagnetic compatibility of the system on circuit boards with densely packed electronic devices. Of course, the second part 320 can also be tilted relative to the ground plane 100; this application does not limit this.

[0062] In one optional embodiment, the extension length of the second part 320 is L1, the extension length of the feed body 200 is L2, and the extension length of the first part 310 is L3, where (L1+L2)<(1 / 4)L3. It should be noted that when this embodiment is combined with the next embodiment, the extension length of the first part 310 is the sum of the extension lengths of the first segment 311 and the second segment 312.

[0063] In this embodiment, (L1+L2) is set to be smaller than (1 / 4)L3. This allows for smaller extension lengths of both the second part 320 and the feed element 200, which helps optimize the antenna's electric field distribution. This makes the amplitude and phase relationship of the two orthogonal polarization components closer to the ideal circular polarization conditions, thereby reducing the axial ratio, improving circular polarization purity, and enhancing the antenna's ability to receive and transmit circularly polarized signals. Furthermore, the smaller extension lengths of both the second part 320 and the feed element 200 reduce their space occupation in the vertical direction, making the circularly polarized antenna more compact and easier to install in space-constrained devices or systems, such as wearable devices and small drones, where antenna size requirements are strict. Of course, (L1+L2) can also be greater than (1 / 4)L3; this application does not limit this.

[0064] In one alternative embodiment, please continue to refer to Figure 3 The ground plane 100 has a first edge 101 and a second edge 102 arranged adjacent to each other. The first part 310 includes a first segment 311 and a second segment 312 connected together. The end of the first segment 311 facing away from the second segment 312 is connected to the second part 320. The end of the second segment 312 facing away from the first segment 311 is connected to the second coupling end. The first segment 311 is parallel to the first edge 101, and the second segment 312 is parallel to the second edge 102. That is, the first segment 311 and the second segment 312 are arranged at an angle.

[0065] In this embodiment, the first segment 311 and the second segment 312, which are at an angle, interact with the ground plane 100, introducing more radiation nulls into the radiation pattern. By rationally designing the position and depth of these nulls, unwanted radiation directions can be effectively suppressed, reducing signal interference. Furthermore, the angled first segment 311 and the second segment 312 increase the complexity of the circularly polarized antenna, resulting in more reactive and resistive elements in the equivalent circuit model of the circularly polarized antenna. This enables good impedance matching over a wider frequency range, thereby improving the operating bandwidth of the circularly polarized antenna. Of course, the first part 310 may also include only the second segment 312 parallel to the second edge 102 without including the first segment 311; this application does not limit this.

[0066] For example, the second segment 312 is connected to the second radiator 400 and is set at an angle. The angle can be 70° to 180°, such as 71°, 80°, 90°, 110°, 115°, 120°, 140°, 151°, 160°, 165°, 170°, 175°, etc. This application does not limit this.

[0067] In one alternative embodiment, please refer to Figure 4 The ground plane 100 has a circular cross-sectional shape, and both the first part 310 and the second radiator 400 have an arc-shaped structure. Furthermore, the first part 310 and the second radiator 400 are concentrically arranged. This allows the circularly polarized antenna of this application to be more adaptable to wearable devices with circular casings, such as smartwatches, enabling a more compact layout of components within the smartwatch and thus reducing its size. For example, the first part 310 can be arc-shaped, and the second radiator 400 can also be arc-shaped. The end of the first part 310 away from the second coupling end bends in a first direction, and the end of the second radiator 400 away from the second coupling end bends in a second direction. The angle between the first and second directions is ninety degrees.

[0068] In one optional embodiment, the ground plane 100 has a first edge 101 and a third edge 103 disposed opposite to each other. The end of the first radiator 300 connected to the ground plane 100 is close to the first edge 101. That is, the end of the first radiator 300 connected to the ground plane 100 is located on the side of the ground plane 100 close to the first edge 101. The power supply port is close to the third edge 103. That is, the power supply port is close to the side of the ground plane 100 close to the third edge 103. This allows the grounding end of the first radiator 300 and the power supply port to be located on opposite sides of the ground plane 100, respectively.

[0069] In this embodiment, the end of the first radiator 300 connected to the ground plane 100 is the grounding end of the first radiator 300. In this embodiment, the grounding end of the first radiator 300 is close to the first edge 101, and the feed port is close to the third edge 103. This allows the grounding end and the feed port of the first radiator 300 to be located on opposite sides of the ground plane 100. When the circularly polarized antenna is working, current will flow through the grounding end and the feed port of the first radiator 300. This will generate a large current at the grounding end and the feed port of the first radiator 300, so that a large current is distributed on both sides of the ground plane 100. This will make the current distribution on both sides of the ground plane 100 more uniform, and make the circular polarization pattern more symmetrical and stable, thereby further improving the circular polarization effect of the circularly polarized antenna.

[0070] In one optional embodiment, the sum of the extension lengths of the first radiator 300 and the feeder 200 is L4, and the sum of the extension lengths of the second radiator 400 and the feeder 200 is L5, where 0.23 ≤ (L5 / L4) ≤ 0.4. For example, (L5 / L4) can be equal to 0.235, 0.239, 0.3, 0.33, 0.36, 0.38, etc., and this application does not limit this to such values.

[0071] In this embodiment, the ratio of L5 to L4 determines the frequency difference between the resonant frequencies of the "loop antenna" formed by the ground plane 100, feed element 200, and first radiator 300, and the "inverted L-shaped antenna" formed by the feed element 200 and second radiator 400. The frequency difference between the "loop antenna" and the "inverted L-shaped antenna" determines the phase difference between the two antennas. In this embodiment, the ratio (L5 / L4) is controlled between 0.23 and 0.4, which makes the phase difference between the "loop antenna" and the "inverted L-shaped antenna" closer to 90 degrees, thereby reducing the axial ratio and achieving good circular polarization performance. Of course, (L5 / L4) can also be greater than 0.4 or less than 0.23, and this application does not limit this.

[0072] In one optional embodiment, the operating wavelength of the circularly polarized antenna is λ, L4 > 0.5λ, and L5 < 0.25λ. This better satisfies the phase difference requirement of the two orthogonal currents in the circular polarization formation condition, helps maintain a stable phase difference between the currents generated by the first radiator 300 and the second radiator 400, and makes the synthesized electric field vector closer to the ideal circular trajectory, thereby improving the circular polarization purity, enhancing the axial ratio performance, and strengthening the circularly polarized antenna's ability to receive and transmit signals in different polarization directions. Of course, L4 can also be less than 0.5λ, and L5 can also be greater than 0.25λ; this application does not impose any limitations on this.

[0073] In one optional embodiment, L4 = (0.6~0.7)λ, and L5 = (0.20~0.24)λ. For example, L4 can be equal to 0.61λ, 0.62λ, 0.627λ, 0.63λ, 0.64, 0.65λ, 0.66λ, 0.663λ, 0.67λ, 0.68λ, 0.695λ, etc., and this application does not limit this; L5 can be equal to 0.21λ, 0.22λ, 0.225λ, 0.23λ, 0.231, 0.235λ, 0.238λ, etc., and this application does not limit this.

[0074] This embodiment can further satisfy the phase difference requirement of the two orthogonal currents in the circular polarization formation conditions, further maintain a stable phase difference between the currents generated by the first radiator 300 and the second radiator 400, and make the synthesized electric field vector closer to the ideal circular trajectory, thereby improving the circular polarization purity, enhancing the axial ratio performance, and strengthening the ability of the circular polarization antenna to receive and transmit signals in different polarization directions.

[0075] In one optional embodiment, L4 = 114–133 mm, and L5 = 38–46 mm. For example, L4 can be equal to 115 mm, 116 mm, 118 mm, 119 mm, 119.4 mm, 120.5 mm, 121.3 mm, 122.8 mm, 125 mm, 128.6 mm, 130.2 mm, 131 mm, 132.5 mm, etc., and this application does not limit this; L5 can be equal to 39 mm, 41 mm, 42 mm, 42.3 mm, 43.8 mm, 44 mm, 44.2 mm, 44.5 mm, 45 mm, etc., and this application does not limit this.

[0076] This application can better meet the phase difference requirement of two orthogonal currents in the circular polarization formation conditions, further maintain a stable phase difference between the currents generated by the first radiator 300 and the second radiator 400, and make the synthesized electric field vector closer to the ideal circular trajectory, thereby improving the circular polarization purity, enhancing the axial ratio performance, and strengthening the ability of the circular polarization antenna to receive and transmit signals in different polarization directions.

[0077] Figure 6 For the reflection coefficient result (S11), from Figure 6 It can be seen that the circularly polarized antenna resonates at 1.575 GHz in the GPS-L1 band, and its impedance bandwidth (-10 dB) can completely cover the GPS-L1 band (1575.42 ± 1.023 MHz).

[0078] Figure 7 The axial ratio of the antenna at a specific angle in space (theta = 0°, phi = 0°, i.e., the +z axis direction) is derived from... Figure 7It can be seen that the axial ratio of the circularly polarized antenna in the GPS-L1 band is less than 3dB, indicating that the axial ratio characteristics of the circularly polarized antenna are good.

[0079] Figure 8 The results show the axial ratio of the circularly polarized antenna at 1.575 GHz in the GPS-L1 band with cross-sections of phi = 0°, 45°, and 90°. The axial ratio of the antenna is less than 3 dB in the range of theta = -36° to 68°, indicating that the axial ratio beam characteristics of the circularly polarized antenna are relatively good.

[0080] Figure 9 This represents the actual right-hand circular gain of the circularly polarized antenna at a frequency of 1.575 GHz and cross-sections of phi = 0°, 45°, and 90°. Combined with... Figure 6 It can be seen that the right-hand circular gain is the highest within the angle range where the axial ratio is less than 3dB. This indicates that the right-hand circular polarization radiation characteristics of the circularly polarized antenna are good.

[0081] Figure 10 and 11 The axial ratio and right-hand circular gain in three dimensions are given, which also demonstrates that the right-hand circular polarization radiation characteristics of the circularly polarized antenna are good.

[0082] This application also discloses a wearable device including the circularly polarized antenna described in any of the above embodiments, thus enabling the wearable device to possess the beneficial effects of the aforementioned circularly polarized antenna, which will not be elaborated further here. For example, the wearable device here may be a smartwatch, smart bracelet, or smart glasses, etc., and this application does not limit the specific type of wearable device.

[0083] The foregoing embodiments of this application focus on describing the differences between various embodiments. As long as the different optimization features between embodiments are not contradictory, they can be combined to form better embodiments. For the sake of brevity, these differences will not be elaborated upon here. The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art, under the guidance of this application, can make many modifications without departing from the spirit and scope of the claims, all of which fall within the protection scope of this application.

Claims

1. A circularly polarized antenna, characterized by, The application relates to a ground plate (100) with a feeding port; a feeding body (200) with a first coupling end and a second coupling end, the first coupling end being electrically connected with the feeding port; a first radiating body (300), one end of the first radiating body (300) being connected with the second coupling end, and the other end being connected with the ground plate (100); and a second radiating body (400), one end of the second radiating body (400) being connected with the second coupling end, and the other end being separated from the ground plate (100), the second radiating body (400) and the first radiating body (300) being respectively located on two sides of the feeding body (200) along the circumference of the ground plate (100); when the first radiating body (300) and the second radiating body (400) resonate in a working frequency band, the electric signals on the first radiating body (300) and the second radiating body (400) satisfy the conditions of equal resonance amplitude and ninety-degree phase difference. The first radiating body (300) comprises a first part (310) and a second part (320) connected with each other, one end of the first part (310) away from the second part (320) is connected with the second coupling end, one end of the second part (320) away from the first part (310) is connected with the ground plate (100), and the first part (310) is parallel to the ground plate (100). The second part (320) is perpendicular to the ground plate (100). The extension length of the second part (320) is L1, the extension length of the feeding body (200) is L2, and the extension length of the first part (310) is L3, (L1+L2) is less than (1 / 4)L3. The ground plate (100) has a first edge (101) and a second edge (102) arranged adjacently, the first part (310) comprises a first segment (311) and a second segment (312) connected with each other, one end of the first segment (311) away from the second segment (312) is connected with the second part (320), and one end of the second segment (312) away from the first segment (311) is connected with the second coupling end. The first segment (311) is parallel to the first edge (101), and the second segment (312) is parallel to the second edge (102).

2. The circularly polarized antenna of claim 1, wherein, The cross-sectional shape of the ground plate (100) is circular, the first part (310) and the second radiating body (400) are both in arc structures, and the first part (310) and the second radiating body (400) are concentrically arranged.

3. The circularly polarized antenna of claim 2, wherein, The ground plate (100) has a first edge (101) and a third edge (103) arranged oppositely, one end of the first radiating body (300) connected with the ground plate (100) is close to the first edge (101), and the feeding port is close to the third edge (103).

4. The circularly polarized antenna of claim 2, wherein, ​ 5. The circularly polarized antenna of any one of claims 2 to 4, wherein, ​ ​ 6. The circularly polarized antenna of any one of claims 2 to 4, wherein, ​ 7. The circularly polarized antenna of claim 1, wherein, ​ 8. The circularly polarized antenna of claim 1, wherein, The sum of the extension lengths of the first radiator (300) and the feeder (200) is L4, and the sum of the extension lengths of the second radiator (400) and the feeder (200) is L5, 0.23≤(L5 / L4)≤0.

4.

9. The circularly polarized antenna of claim 8, wherein, The working wavelength of the circularly polarized antenna is λ, L4>0.5λ, and L5<0.25λ.

10. The circularly polarized antenna of claim 9, wherein, L4=(0.6-0.7)λ, and L5=(0.20-0.24)λ.

11. The circularly polarized antenna of claim 8, wherein, L4=114-133mm, and L5=38-46mm.

12. A wearable device, comprising: The circularly polarized antenna as claimed in any one of claims 1 to 11. The circularly polarized antenna as claimed in any one of claims 1 to 11.

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