Circularly polarized positioning antenna and wearable device

Abstract

The invention discloses a circularly polarized positioning antenna and wearable equipment. The circularly polarized positioning antenna comprises a first annular radiator working at a first frequency band; the coupling connection with the first annular radiator is a first branch knot, and the first branch knot is used for accessing a first feed signal to excite the first annular radiator to work in a first radiation mode; the second branch knot is in coupling connection with the first annular radiator, a preset distance is formed between the second branch knot and the first branch knot, the second branch knot is used for being grounded or used for being connected with a second feed signal, and the two radiation modes have the same amplitude and the 90-degree phase difference, that is, the annular radiator generates right-handed circularly polarized radiation. Therefore, the positioning antenna can better receive the navigation satellite signal, and the right-handed circularly polarized radiation generated by the annular radiator can also filter the left-handed circularly polarized navigation satellite signal reflected by the high-rise building or the ground to reduce multipath interference, thereby effectively improving the positioning precision of the positioning antenna of the wearable device.

Description

Technical Field

[0001] This application belongs to the technical field of antennas, and particularly relates to a circularly polarized positioning antenna and a wearable device. Background Art

[0002] In the field of smart watches or bracelets, positioning accuracy has always been a pain point that people are concerned about. Most of the positioning antennas of traditional smart watches or bracelets are linearly polarized antennas. However, the signals sent by navigation satellites are right-handed circularly polarized signals after passing through the ionosphere. Therefore, the positioning antennas of smart watches or bracelets cannot fully receive the signals of navigation satellites. Moreover, after the signals of navigation satellites are reflected an odd number of times by the ground, high-rise buildings, trees, etc., they will become left-handed circularly polarized signals, and the resulting multipath interference will seriously affect the positioning effect of the whole machine. Summary of the Invention

[0003] The purpose of this application is to provide a circularly polarized positioning antenna and a wearable device, aiming to solve the technical problem of the low positioning accuracy of the antenna of the existing wearable device.

[0004] In the first aspect of the embodiment of this application, a circularly polarized positioning antenna is provided, including:

[0005] A first annular radiator, which operates in a first frequency band;

[0006] A first stub, which is coupled to the first annular radiator. One end of the first stub far from the first annular radiator is used to access a first feeding signal to excite the first annular radiator to operate in a first radiation mode;

[0007] A second stub, which is coupled to the first annular radiator and has a preset distance from the first stub. One end of the second stub far from the first annular radiator is used for grounding or for accessing a second feeding signal to excite the first annular radiator to operate in a second radiation mode. The phase difference between the first feeding signal and the second feeding signal is 90°.

[0008] The above circularly polarized positioning antenna is coupled and fed by one stub, and the other stub is also coupled and fed or grounded, so as to excite two radiation modes of the first annular radiator. The two radiation modes have the same amplitude and a phase difference of 90 degrees, that is, the first annular radiator generates right-handed circularly polarized radiation, so that the positioning antenna can better receive the signals of navigation satellites. At the same time, the right-handed circularly polarized radiation generated by the first annular radiator can also filter the left-handed circularly polarized navigation satellite signals reflected by high-rise buildings or the ground to reduce multipath interference, thereby effectively improving the positioning accuracy of the positioning antenna of the wearable device.

[0009] In one embodiment, it further includes a second annular radiator coupled to the first annular radiator 10. The second annular radiator operates in a second frequency band. One of the first annular radiator and the second annular radiator is disposed on the outer periphery of the other and they are isolated from each other.

[0010] By coupling the two annular radiators to each other, two radiation modes of the second annular radiator are realized. The amplitudes of the two radiation modes are equal and the phases differ by 90°, also achieving a circular polarization effect; the two annular radiators act together to achieve dual-band circular polarization.

[0011] In one embodiment, the centers of the first annular radiator and the second annular radiator fall on the same axis.

[0012] In one embodiment, the perimeter of the first annular radiator corresponds to the wavelength of the first frequency band.

[0013] In one embodiment, the perimeter of the second annular radiator corresponds to the wavelength of the second frequency band.

[0014] In one embodiment, a plurality of first inductor components are provided on the first annular radiator, and the inductor components are arranged at intervals along the circumferential direction of the first annular radiator; and / or

[0015] A plurality of second inductor components are provided on the second annular radiator, and the second inductor components are arranged at intervals along the circumferential direction of the second annular radiator.

[0016] In one embodiment, the first inductor component and the second inductor component are lumped inductors or distributed inductors.

[0017] In one embodiment, the first stub and the second stub both include a first coupling section and a second coupling section. The long side of the first coupling section is directly opposite to the edge of the first annular radiator and a coupling gap is provided therebetween. The first end of the second coupling section is connected to the first coupling section, and the second end extends in a direction away from the first coupling section and serves as the end away from the first annular radiator.

[0018] By adjusting the dimensions of the stub and the spacing of the coupling gap, the coupling degree can be adjusted to achieve matching tuning of the antenna.

[0019] In one embodiment, the plane where the first stub is located, the plane where the second stub is located are perpendicular to the plane where the first annular radiator is located, or

[0020] The projections of the first stub and the second stub in the direction perpendicular to the plane where the first annular radiator is located fall outside the range of this plane.

[0021] In one embodiment, the main bodies of the first stub and the second stub are of a T-shaped structure or an inverted L-shaped structure.

[0022] In one embodiment, both the first stub and the second stub include a capacitor and a first coupling section. One end of the capacitor is connected to the first annular radiator, and the other end is connected to the first end of the first coupling section. The second end of the first coupling section serves as the end far from the first annular radiator. This example provides another implementation manner of the stub.

[0023] In one embodiment, the first annular radiator and the second annular radiator are of a square annular structure, a rounded square annular structure, a rectangular annular structure, a rounded rectangular annular structure, an elliptical annular structure, or a circular ring structure.

[0024] In one embodiment, the preset distance along the circumference of the first annular radiator for the first stub and the second stub is 0.125 times to 0.375 times the wavelength of the first frequency band.

[0025] A second aspect of the embodiments of the present application provides a wearable device, including a circuit board and the circularly polarized positioning antenna as described above. The first stub of the circularly polarized positioning antenna is connected to the first radio frequency port of the circuit board, and the second stub of the circularly polarized positioning antenna is connected to the second radio frequency port or the ground port of the circuit board.

[0026] The above wearable device adopts all the embodiments of the above circularly polarized positioning antenna, and thus has at least all the beneficial effects of the above embodiments, which will not be elaborated herein one by one. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of a single-feed single-frequency circularly polarized positioning antenna provided by an embodiment of the present invention;

[0028] Figure 2 It is a schematic structural diagram of a dual-feed single-frequency circularly polarized positioning antenna provided by Embodiment 1 of the present invention;

[0029] Figure 3 It is a schematic structural diagram of a dual-feed single-frequency circularly polarized positioning antenna provided by Embodiment 2 of the present invention;

[0030] Figure 4 It is a schematic diagram of S parameters of a dual-feed single-frequency circularly polarized positioning antenna provided by an embodiment of the present invention;

[0031] Figure 5 It is a top two-dimensional axial ratio simulation diagram of a dual-feed single-frequency circularly polarized positioning antenna provided by an embodiment of the present invention;

[0032] Figure 6The 2D four-axis ratio simulation diagrams of the phi = 0°, 45°, 90°, and 135° sections of the dual-feed single-frequency circularly polarized positioning antenna provided by the embodiments of the present invention;

[0033] Figure 7 The 2D right-handed circular polarization gain schematic diagram of the dual-feed single-frequency circularly polarized positioning antenna provided by the embodiments of the present invention;

[0034] Figure 8 The structural schematic diagram of the single-feed dual-frequency circularly polarized positioning antenna provided by the embodiments of the present invention;

[0035] Figure 9 The structural schematic diagram of the dual-feed dual-frequency circularly polarized positioning antenna provided by the embodiments of the present invention;

[0036] Figure 10 The S-parameter schematic diagram of the single-feed dual-frequency circularly polarized positioning antenna provided by the embodiments of the present invention;

[0037] Figure 11 The top 2D axis ratio simulation diagram of the single-feed dual-frequency circularly polarized positioning antenna when the second annular radiator is working;

[0038] Figure 12 The top 2D axis ratio simulation diagram of the single-feed dual-frequency circularly polarized positioning antenna when the first annular radiator is working;

[0039] Figure 13 The top 2D right-handed circular polarization gain schematic diagram of the single-feed dual-frequency circularly polarized positioning antenna when the second annular radiator is working;

[0040] Figure 14 The top 2D right-handed circular polarization gain schematic diagram of the single-feed dual-frequency circularly polarized positioning antenna when the first annular radiator is working;

[0041] Figure 15 The 2D four-axis ratio simulation diagrams of the phi = 0° and 90° sections of the single-feed dual-frequency circularly polarized positioning antenna when the second annular radiator is working;

[0042] Figure 16 The 2D four-axis ratio simulation diagrams of the phi = 0° and 90° sections of the single-feed dual-frequency circularly polarized positioning antenna when the first annular radiator is working;

[0043] Figure 17 The right-handed circular polarization gain schematic diagram of the single-feed dual-frequency circularly polarized positioning antenna when the second annular radiator is working;

[0044] Figure 18Schematic diagram of the right - hand circular polarization gain when the first annular radiator of the single - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention is working;

[0045] Figure 19 Schematic diagram of the S - parameters of the dual - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention;

[0046] Figure 20 Top two - dimensional axial ratio simulation diagram when the second annular radiator of the dual - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention is working;

[0047] Figure 21 Top two - dimensional axial ratio simulation diagram when the first annular radiator of the dual - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention is working;

[0048] Figure 22 Two - dimensional four - axial ratio simulation diagrams of the phi = 0°, 45°, 90°, 135° sections when the second annular radiator of the dual - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention is working;

[0049] Figure 23 Two - dimensional four - axial ratio simulation diagrams of the phi = 0°, 45°, 90°, 135° sections when the first annular radiator of the dual - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention is working;

[0050] Figure 24 Schematic diagram of the two - dimensional right - hand circular polarization gain when the second annular radiator of the dual - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention is working;

[0051] Figure 25 Schematic diagram of the two - dimensional right - hand circular polarization gain when the first annular radiator of the dual - feed dual - frequency circular polarization positioning antenna provided by the embodiment of the present invention is working. Detailed implementation manners

[0052] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the following further describes the present application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0053] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0054] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0055] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0056] Please refer to Figure 1 and Figure 2 , a circularly polarized positioning antenna provided by an embodiment of the present application and applicable to a wearable device includes: a first annular radiator 10, a first branch 20, and a second branch 30.

[0057] The first annular radiator 10 operates in a first frequency band, such as 1.575 GHz or 1.176 GHz. Optionally, the main body of the first annular radiator 10 is a centrosymmetric structure or an axisymmetric structure, such as a circular ring structure, a square ring structure, a rounded square ring structure, a rectangular ring structure, a rounded rectangular ring structure, an elliptical ring structure, etc., ensuring that two modes of excitation with equal amplitude and a 90° phase difference are generated on the antenna, realizing the circular polarization characteristic of the antenna.

[0058] The first branch 20 is coupled to the first annular radiator 10, and one end of the first branch 20 away from the first annular radiator 10 is used to access a first feeding signal to excite the first annular radiator 10 to operate in a first radiation mode; the second branch 30 is coupled to the first annular radiator 10 and has a preset distance from the first branch 20.

[0059] Please refer to Figure 1 , in one embodiment, one end of the second branch 30 away from the first annular radiator 10 is used to ground 100 to excite the first annular radiator 10 to operate in a second radiation mode. Please refer to Figure 2 , in another embodiment, one end of the second branch 30 away from the first annular radiator 10 is used to access a second feeding signal to excite the first annular radiator 10 to operate in a second radiation mode, and the phase difference between the first feeding signal and the second feeding signal of the alternating current signal is 90°. The performances of the two implementation manners are similar, and either can be selected according to needs during application.

[0060] The above-mentioned circularly polarized positioning antenna and the wearable device are coupled and fed through a stub, and the other stub is also coupled and fed or grounded 100, so as to excite two radiation modes of the first annular radiator 10. The two radiation modes have the same amplitude and a phase difference of 90 degrees, that is, the first annular radiator 10 generates right-handed circularly polarized radiation, so that the positioning antenna can better receive navigation satellite signals. At the same time, the right-handed circularly polarized radiation generated by the first annular radiator 10 can also filter the left-handed circularly polarized navigation satellite signals reflected by high-rise buildings or the ground to reduce multipath interference, thereby effectively improving the positioning accuracy of the positioning antenna of the wearable device.

[0061] In one embodiment, the perimeter of the first annular radiator 10 corresponds to the wavelength of the first frequency band. For example, the perimeter of the first annular radiator 10 is substantially equal to the wavelength of the first frequency band, or the perimeter of the first annular radiator 10 is substantially equal to 1 / 4 of the wavelength of the first frequency band, ensuring that the antenna resonates at the required frequency point.

[0062] In one embodiment, the preset distance between the first stub 20 and the second stub 30 along the periphery of the first annular radiator 10 is 0.1 to 0.5 times the wavelength of the first frequency band, and generally 0.125 to 0.375 times is selected. It should be noted that when the first annular radiator 10 is a square structure, a rounded square structure, a rectangular structure or a rounded rectangular structure, the two stubs are respectively coupled and connected to two adjacent sides of the first annular radiator 10, such as Figure 1 and Figure 2 In the solution provided by the embodiment, the first stub 20 and the second stub 30 are respectively arranged at the midpoint positions of two adjacent sides of the square-shaped first annular radiator 10. At this time, the antenna has a better and good circular polarization effect.

[0063] In one embodiment, the coupling between the stub and the radiator is a slot coupling feed, which is easier to match and tune. Specifically, the first stub 20 and / or the second stub 30 includes a first coupling section and a second coupling section. The long side of the first coupling section is directly opposite to the edge of the first annular radiator 10, and a coupling slot is provided therebetween. The first end of the second coupling section is connected to the first coupling section, and the second end extends away from the first coupling section and serves as the end away from the first annular radiator 10. Thus, the main body of the stub forms a T-shaped structure or an inverted L-shaped structure, and by adjusting the size of the stub and the spacing of the coupling slot, the coupling degree can be adjusted to achieve the matching and tuning of the antenna.

[0064] In some embodiments, the plane where the first stub 20 is located, the plane where the second stub 30 is located, and the plane where the first annular radiator 10 is located are perpendicular to each other; in other embodiments, the projections of the first stub 20 and the second stub 30 in the direction perpendicular to the plane where the first annular radiator 10 is located fall outside the range of the first annular radiator 10, and the included angles formed by the plane where the first stub 20 is located, the plane where the second stub 30 is located, and the plane where the first annular radiator 10 is located are between ±90°.

[0065] In other embodiments, the stubs and the radiator are directly fed. The first stub 20 and / or the second stub 30 each include a capacitor and a third coupling section. One end of the capacitor is connected to the first annular radiator 10, and the other end is connected to the first end of the third coupling section. The second end of the third coupling section is the end far from the first annular radiator 10. In this way, another implementation manner of the stub and the coupling is provided. By selecting capacitors with different capacitances, the coupling degree can be adjusted to achieve the matching tuning of the antenna. It can be understood that the first stub 20 and the second stub 30 can choose the same coupling manner or different coupling manners in the above two coupling manners.

[0066] Please refer to Figure 3 , in a further embodiment, to achieve miniaturization, a plurality of first inductive elements 40 are provided on the first annular radiator 10, and the first inductive elements 40 are arranged at intervals along the circumferential direction of the first annular radiator 10. Optionally, the first inductive elements 40 are equally spaced along the circumferential direction of the first annular radiator 10. Of course, they may not be equally spaced, and can be specifically adjusted according to actual needs. The first inductive elements 40 are provided in this embodiment mainly to extend the physical length of the first annular radiator 10, so as to reduce the size of the positioning antenna and effectively miniaturize the antenna. Optionally, the first inductive elements 40 can usually be lumped inductors, that is, inductors, or can also be serpentine bent traces.

[0067] It can be seen from Figure 3 that in this embodiment, four first inductive elements 40 are provided on the first annular radiator 10, but in fact, it is not limited to this. Different numbers of first inductive elements 40 can also be set according to different size requirements. Usually, in order to achieve a good circular polarization effect, the first inductive elements 40 are equally spaced along the circumferential direction of the first annular radiator 10, and each first inductive element 40 is arranged at the position with the maximum current, such as the midpoint positions of the sides of the square first annular radiator 10. The inductance value range of the first inductive elements 40 can be flexibly selected according to the specific operating frequency band and the limited size. The larger the inductance, the smaller the volume of the annular radiator can be. In some cases where higher miniaturization is required, most or all of the sides of the annular radiator can be composed of distributed inductance, that is, most or all of the sides are serpentine bent traces, or multiple inductors are loaded.

[0068] From Figure 4 It can be seen that the above-mentioned circularly polarized positioning antenna resonates at 1.575 GHz in the GPS (Global Positioning System) L1 band, and the impedance bandwidth (S11 < -6 dB) can completely cover the entire GPS-L1 band (1575 ± 2 MHz), indicating that the above-mentioned positioning antenna has good reception of navigation satellite signals.

[0069] From Figure 5 and Figure 6 It can be seen that when the above-mentioned positioning antenna operates in the L1 band of GPS, the axial ratio at the top (phi = 0°, theta = 0°) of the positioning antenna is below 5 dB. When the above-mentioned positioning antenna operates at 1.575 GHz in the GPS-L1 band and the cross-section is phi = 0°, 45°, 90°, 135°, within the range of θ = -60 to 60°, the axial ratio of the positioning antenna is less than 10 dB, indicating that the axial ratio characteristic of the above-mentioned positioning antenna is good and meets the performance requirements of the positioning antenna.

[0070] From Figure 7 It can be seen that when the above-mentioned positioning antenna operates at 1.575 GHz in the GPS-L1 band, the right-handed circular polarization gain at the top (phi = 0°, theta = 0°) of the positioning antenna is about 2.1 dB. Under the condition of the same gain, the signal received by this circularly polarized antenna is 3 dB higher than that of the traditional linearly polarized antenna. Therefore, the positioning effect of the above-mentioned positioning antenna is better than that of the traditional linearly polarized antenna.

[0071] Please refer to Figure 8 , the circularly polarized positioning antenna provided by the embodiment of the present application can also achieve dual-band circular polarization. In this embodiment, the circularly polarized positioning antenna further includes a second ring radiator 50 coupled to the first ring radiator 10. The second ring radiator 50 operates in the second band. One of the first ring radiator 10 and the second ring radiator 50 is disposed on the outer periphery of the other and is isolated from each other. It can be understood that the sizes of the first ring radiator 10 and the second ring radiator 50 are set according to their different operating bands. For example, if the first ring radiator 10 operates at 1.575 GHz and the second ring radiator 50 operates at 1.176 GHz, then the first ring radiator 10 will be on the outer periphery of the second ring radiator 50.

[0072] By coupling two loop radiators with each other, two radiation modes of the second loop radiator 50 are realized. The amplitudes of the two radiation modes are equal and the phases differ by 90°, achieving the circular polarization effect as well. The two loop radiators work together to achieve dual-band circular polarization. When the first loop radiator 10 needs to work, a feeding signal matching its operating frequency is connected. When the second loop radiator 50 needs to work, a feeding signal matching its operating frequency is connected. In this way, the dual-band circular polarization positioning antenna of this embodiment works in a time-sharing manner, can match the positioning signals of two frequency bands, and improves the positioning accuracy.

[0073] Generally, the first loop radiator 10 and the second loop radiator 50 have the same shape, or different shapes can also be set according to requirements. The second loop radiator 50 is similar to the first loop radiator 10 and is a centrosymmetric structure or an axisymmetric structure, such as a circular ring structure, a square loop structure, a rounded square loop structure, a rectangular loop structure, a rounded rectangular loop structure, an elliptical loop structure, etc., ensuring the excitation of two modes with equal amplitude and a phase difference of 90° on the antenna and realizing the circular polarization characteristic of the antenna.

[0074] In one of the embodiments, to achieve a good circular polarization effect, the centers of the first loop radiator 10 and the second loop radiator 50 are on the same axis, making the coupling degree in all directions of the two balanced.

[0075] In one of the embodiments, the perimeter of the second loop radiator 50 corresponds to the wavelength of the second frequency band. For example, the perimeter of the second loop radiator 50 is basically equal to the wavelength of the second frequency band, or the perimeter of the second loop radiator 50 is basically equal to 1 / 4 of the wavelength of the second frequency band, ensuring that the antenna resonates at the required frequency points.

[0076] Please refer to Figure 9 , in one of the embodiments, for miniaturization, a plurality of second inductor devices 60 are provided on the second loop radiator 50, and the second inductor devices 60 are arranged at intervals along the circumference of the second loop radiator 50. Optionally, the second inductor devices 60 are equally spaced along the circumference of the second loop radiator 50. Of course, they can also be not equally spaced, and can be adjusted according to actual needs specifically. The second inductor devices 60 are provided in this embodiment mainly to extend the physical length of the second loop radiator 50 to reduce the size of the positioning antenna and enable the antenna to effectively achieve miniaturization. Optionally, the second inductor devices 60 can usually be lumped inductors, that is, inductors, and can also be serpentine bent traces.

[0077] By Figure 9It can be seen that in this embodiment, four second inductance devices 60 are provided on the second ring radiator 50, but in fact it is not limited to this. Different numbers of second inductance devices 60 can also be provided according to different size requirements. Usually, in order to achieve a good circular polarization effect, each second inductance device 60 is arranged at equal intervals in the circumferential direction of the second ring radiator 50, and each second inductance device 60 is provided at the position with the largest current, such as the midpoint position of each side of the square-shaped second ring radiator 50. The inductance value range of the second inductance device 60 can be flexibly selected according to the specific working frequency band and the limited size. The larger the inductance, the smaller the volume of the ring radiator can be. In some cases where miniaturization is required to be high, most or all of the sides of the ring radiator can be composed of distributed inductance, that is, most or all of the sides are serpentine curved routing, or multiple inductors are loaded.

[0078] There is a coupling gap between the first annular radiator 10 and the second annular radiator 50. By adjusting the spacing of the coupling gap, the coupling degree can be adjusted to achieve matching tuning of the antenna.

[0079] from Figure 10 It can be seen that the above Figure 8 The single-feed dual-frequency circularly polarized positioning antenna shown produces a resonance at 1.575 GHz in the GPS-L1 band and another resonance at 1.176 GHz in the GPS-L5 band, and the impedance bandwidth (S11<-6dB) can completely cover the entire GPS-L1 band (1575±2MHz) and GPS-L5 band (1176±2MHz), indicating good reception of navigation satellite signals.

[0080] from Figure 11 , 13 , 15, 17, it can be seen that the above Figure 8 When the positioning antenna shown works in the L5 frequency band of GPS 1.176 GHz, the axial ratio of the top of the positioning antenna (phi=0°, theta=0°) is below 1 dB, and the right-hand circular polarization gain of the top is about 1.9 dB. When the above positioning antenna works in the L5 frequency band of GPS 1.176 GHz and the section is phi=0°, 90°, in the range of θ=-60~75°, the axial ratio of the positioning antenna is less than 10 dB, indicating that the axial ratio characteristics of the above positioning antenna are good and meet the performance requirements of the positioning antenna.

[0081] from Figure 12 , 14 , 16, 18, it can be seen that the above Figure 8When the positioning antenna shown operates at the L1 frequency band of GPS, 1.575 GHz, the axial ratio at the top of the positioning antenna (phi = 0°, theta = 0°) is below 3 dB, and the right-hand circular polarization gain at the top is about 2.8 dB. When the above positioning antenna operates at the L1 frequency band of GPS, 1.575 GHz, and the cross-section is phi = 0°, 90°, within the range of θ = -75 to 50°, the axial ratio of the positioning antenna is less than 10 dB, indicating that the axial ratio characteristic of the above positioning antenna is good and meets the performance requirements of the positioning antenna. Under the same gain, the circular polarization antenna can receive satellite signals 3 dB higher than the traditional linear polarization antenna, and the positioning effect of the above positioning antenna is better than that of the traditional linear polarization antenna.

[0082] From Figure 19 It can be seen that the above Figure 9 shown dual-feed dual-band circular polarization positioning antenna resonates at 1.575 GHz in the GPS-L1 frequency band and generates another resonance at 1.176 GHz in the GPS-L5 frequency band, and the impedance bandwidth (S11 < -6 dB) can fully cover the entire GPS-L1 frequency band (1575 ± 2 MHz) and GPS-L5 frequency band (1176 ± 2 MHz), indicating good reception of navigation satellite signals.

[0083] From Figure 20 , 22 , 24 It can be seen that the above Figure 9 shown positioning antenna operates at 1.176 GHz in the L5 frequency band of GPS. The axial ratio at the top of the positioning antenna (phi = 0°, theta = 0°) is below 5.6 dB. When the above positioning antenna operates at 1.176 GHz in the L5 frequency band of GPS and the cross-section is phi = 0°, 45°, 90°, 135°, within the range of θ = -60 to 60°, the axial ratio of the positioning antenna is less than 10 dB, indicating that the axial ratio characteristic of the above positioning antenna is good and meets the performance requirements of the positioning antenna. The above Figure 9 shown positioning antenna operates at 1.176 GHz in the L5 frequency band of GPS. The right-hand circular polarization gain at the top of the positioning antenna (phi = 0°, theta = 0°) is about 2.4 dB. Under the same gain, the circular polarization antenna can receive satellite signals 3 dB higher than the traditional linear polarization antenna, and the positioning effect of the above positioning antenna is better than that of the traditional linear polarization antenna.

[0084] From Figure 21 , 23 , 25 It can be seen that the above Figure 9When the positioning antenna shown operates at the L1 frequency band of GPS, which is 1.575 GHz, the axial ratio at the top of the positioning antenna (phi = 0°, theta = 0°) is below 4.5 dB. When the above-mentioned positioning antenna operates at the L1 frequency band of GPS, which is 1.575 GHz, and the cutting planes are phi = 0°, 45°, 90°, and 135°, within the range of θ = -55 to 60°, the axial ratio of the positioning antenna is less than 10 dB, indicating that the axial ratio characteristic of the above-mentioned positioning antenna is good and meets the performance requirements of the positioning antenna. The above Figure 9 When the positioning antenna shown operates at the L1 frequency band of GPS, which is 1.176 GHz, the right-hand circular polarization gain at the top of the positioning antenna (phi = 0°, theta = 0°) is about 0.9 dB. Under the condition of the same gain, the satellite signal received by this circular polarization antenna is 3 dB higher than that of the traditional linear polarization antenna. The positioning effect of the above-mentioned positioning antenna is better than that of the traditional linear polarization antenna.

[0085] In addition, the present application also provides a wearable device, including a circuit board and the circular polarization positioning antenna described in any one of the foregoing embodiments. One end of the first branch of the circular polarization positioning antenna, which is far from the first annular radiator, is connected to the first radio frequency port of the circuit board, and one end of the second branch of the circular polarization positioning antenna, which is far from the first annular radiator, is connected to the second radio frequency port or the ground port of the circuit board.

[0086] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A circularly polarized positioning antenna, characterized in that, it includes: A first annular radiator, which operates in a first frequency band, and the first annular radiator is a centrosymmetric structure or an axially symmetric structure; A first stub, which is coupled to the first annular radiator, and one end of the first stub away from the first annular radiator is used to access a first feeding signal to excite the first annular radiator to operate in a first radiation mode; A second stub, which is coupled to the first annular radiator and has a preset distance from the first stub. One end of the second stub away from the first annular radiator is used for grounding or for accessing a second feeding signal to excite the first annular radiator to operate in a second radiation mode, and the phase difference between the first feeding signal and the second feeding signal is 90°; Both the first stub and / or the second stub include a first coupling section and a second coupling section. The long side of the first coupling section is directly opposite to the edge of the first annular radiator and a coupling gap is provided therebetween. The first end of the second coupling section is connected to the first coupling section, and the second end extends in a direction away from the first coupling section and serves as the end away from the first annular radiator; Or, Both the first stub and / or the second stub include a capacitor and a third coupling section. One end of the capacitor is connected to the first annular radiator, and the other end is connected to the first end of the third coupling section. The second end of the third coupling section serves as the end away from the first annular radiator.

2. The circularly polarized positioning antenna according to claim 1, characterized in that, it further includes a second annular radiator coupled to the first annular radiator. The second annular radiator operates in a second frequency band. One of the first annular radiator and the second annular radiator is disposed on the outer periphery of the other and they are isolated from each other.

3. The circularly polarized positioning antenna according to claim 2, characterized in that, the second annular radiator is a centrosymmetric structure or an axially symmetric structure.

4. The circularly polarized positioning antenna according to claim 2, characterized in that, the first annular radiator and the second annular radiator have the same shape.

5. The circularly polarized positioning antenna according to claim 2, characterized in that, there is a coupling gap between the first annular radiator and the second annular radiator.

6. The circularly polarized positioning antenna according to claim 2, characterized in that, the centers of the first annular radiator and the second annular radiator are on the same axis.

7. The circularly polarized positioning antenna according to claim 1, characterized in that, the perimeter of the first annular radiator corresponds to the wavelength of the first frequency band.

8. The circularly polarized positioning antenna according to claim 2, characterized in that, the perimeter of the second annular radiator corresponds to the wavelength of the second frequency band.

9. The circularly polarized positioning antenna according to claim 2, characterized in that, a plurality of first inductive components are provided on the first annular radiator, and the first inductive components are arranged at intervals along the circumference of the first annular radiator; and / or A plurality of second inductor devices are provided on the second annular radiator, and the second inductor devices are arranged at intervals along the circumferential direction of the second annular radiator.

10. The circularly polarized positioning antenna according to claim 9, wherein: The first inductor device and the second inductor device are lumped inductors or distributed inductors.

11. The circularly polarized positioning antenna according to claim 9, wherein: Each of the first inductor devices is arranged at equal intervals in the circumferential direction of the first annular radiator; and / or Each of the second inductor devices is arranged at equal intervals in the circumferential direction of the second annular radiator.

12. The circularly polarized positioning antenna according to claim 1, wherein: The plane where the first branch is located, the plane where the second branch is located are perpendicular to the plane where the first annular radiator is located, or The projections of the first branch and the second branch in the direction perpendicular to the plane where the first annular radiator is located fall outside the range of the first annular radiator.

13. The circularly polarized positioning antenna according to claim 1, wherein: The included angle formed by the plane where the first branch is located, the plane where the second branch is located and the plane where the first annular radiator is located is between ±90°.

14. The circularly polarized positioning antenna according to claim 1, wherein: The main bodies of the first branch and the second branch are T-shaped structures or inverted L-shaped structures.

15. The circularly polarized positioning antenna according to any one of claims 2 to 14, wherein: The first annular radiator and the second annular radiator are square annular structures, rounded square annular structures, rectangular annular structures, rounded rectangular annular structures, elliptical annular structures or circular ring structures.

16. The circularly polarized positioning antenna according to any one of claims 1 to 14, wherein: The preset distance of the first branch and the second branch along the periphery of the first annular radiator is 0.1 times to 0.5 times the wavelength of the first frequency band.

17. The circularly polarized positioning antenna according to any one of claims 1 to 14, wherein: The preset distance of the first branch and the second branch along the periphery of the first annular radiator is 0.125 times to 0.375 times the wavelength of the first frequency band.

18. The circularly polarized positioning antenna according to any one of claims 1 to 14, wherein: When the first annular radiator is a square structure, a rounded square structure, a rectangular structure or a rounded rectangular structure, the first branch and the second branch are respectively coupled and connected to two adjacent sides of the first annular radiator.

19. The circularly polarized positioning antenna according to claim 18, wherein: The first branch and the second branch are respectively coupled and connected to the midpoint positions of two adjacent sides of the first annular radiator.

20. A wearable device, wherein: Comprising a circuit board and a circularly polarized positioning antenna as described in any one of claims 1 to 19, one end of the first branch of the circularly polarized positioning antenna, which is away from the first annular radiator, is connected to the first RF port of the circuit board, and one end of the second branch of the circularly polarized positioning antenna, which is away from the first annular radiator, is connected to the second RF port or the ground port of the circuit board.

Images