Circularly polarized positioning antennas and wearable devices

Abstract

A circularly polarized positioning antenna and a wearable device, the circularly polarized positioning antenna comprising: a first annular radiator operating in a first frequency band; a first branch coupled to the first annular radiator, the first branch being used to access a first feed signal to excite the first annular radiator to operate in a first radiation mode; a second branch coupled to the first annular radiator and having a preset distance from the first branch, the second branch being used to be grounded or to access a second feed signal, the two radiation modes having the same amplitude and a phase difference of 90 degrees, that is, the annular radiator generates right-handed circularly polarized radiation, so that the positioning antenna can better receive navigation satellite signals, and at the same time, the right-handed circularly polarized radiation generated by the annular radiator can also filter left-handed circularly polarized navigation satellite signals reflected by high-rise buildings or the ground, so as to reduce multipath interference, thereby effectively improving the positioning accuracy of the positioning antenna of the wearable device.

Description

Technical Field

[0001] The present application belongs to the field of antenna technology, and in particular relates to a circularly polarized positioning antenna and a wearable device. Background Art

[0002] In the field of smart watches or wristbands, positioning accuracy has always been a pain point that people are concerned about. Traditional smart watches or wristbands have linearly polarized positioning antennas, but the signals sent by navigation satellites are right-hand circularly polarized signals after passing through the ionosphere. Therefore, the positioning antennas of smart watches or wristbands cannot receive all the signals from navigation satellites. The signals from navigation satellites are reflected an odd number of times by the ground, tall buildings, trees, etc., and become left-hand circularly polarized signals. The multipath interference generated will seriously affect the positioning effect of the entire device. 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 low antenna positioning accuracy of existing wearable devices.

[0004] A first aspect of an embodiment of the present application provides a circularly polarized positioning antenna, comprising:

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

[0006] A first branch node is coupled to the first annular radiator, wherein an end of the first branch node away from the first annular radiator is used to receive a first feeding signal to excite the first annular radiator to work in a first radiation mode;

[0007] A second branch is coupled to the first annular radiator and has a preset distance from the first branch. An end of the second branch away from the first annular radiator is used for grounding or for connecting a second feeding signal to excite the first annular radiator to operate in a second radiation mode. The first feeding signal and the second feeding signal differ in phase by 90°.

[0008] The above-mentioned circularly polarized positioning antenna is coupled and fed through a branch, and the other branch is also coupled and fed or grounded, thereby exciting 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 navigation satellite signals. 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, a second ring radiator coupled to the first ring radiator 10 is further included, the second ring radiator operates in a second frequency band, and one of the first ring radiator and the second ring radiator is arranged on the periphery of the other and 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 two radiation modes have equal amplitudes and a phase difference of 90°, and the circular polarization effect is also achieved. The two annular radiators work together to achieve dual-frequency circular polarization.

[0011] In one embodiment, the center of the first annular radiator and the center of the second annular radiator are located on the same axis.

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

[0013] In one embodiment, the circumference of the second ring-shaped radiator corresponds to the wavelength of the second frequency band.

[0014] In one of the embodiments, a plurality of first inductance devices are disposed on the first annular radiator, and the inductance devices are arranged at intervals along the circumference of the first annular radiator; and / or

[0015] A plurality of second inductance devices are disposed on the second annular radiator, and the second inductance devices are arranged at intervals along the circumference of the second annular radiator.

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

[0017] In one embodiment, the first branch and the second branch both include a first coupling segment and a second coupling segment, the long side of the first coupling segment 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 segment is connected to the first coupling segment, and the second end extends in a direction away from the first coupling segment and serves as the end away from the first annular radiator.

[0018] By adjusting the size of the branches and the spacing of the coupling gaps, the coupling degree can be adjusted to achieve matching tuning of the antenna.

[0019] In one embodiment, the plane where the first branch node is located, the plane where the second branch node is located, and the plane where the first annular radiator is located are perpendicular to each other, or

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

[0021] In one embodiment, the main body of the first branch node and the second branch node is a T-shaped structure or an inverted L-shaped structure.

[0022] In one embodiment, the first branch and the second branch both include a capacitor and a first coupling segment, 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 segment, and the second end of the first coupling segment serves as the end away from the first annular radiator. This example provides another implementation method of the branch.

[0023] In one embodiment, 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 annular structures.

[0024] In one embodiment, the preset distance between the first branch and the second branch along the periphery of the first annular radiator is 0.125 to 0.375 times the wavelength of the first frequency.

[0025] The second aspect of an embodiment of the present application provides a wearable device, comprising a circuit board and the circularly polarized positioning antenna as described above, wherein the first branch of the circularly polarized positioning antenna is connected to the first RF port of the circuit board, and the second branch of the circularly polarized positioning antenna is connected to the second RF port of the circuit board or the ground port of the circuit board.

[0026] The above-mentioned wearable device adopts all the embodiments of the above-mentioned circularly polarized positioning antenna, and thus has at least all the beneficial effects of the above-mentioned embodiments, which will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of a single-feed single-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the structure of a dual-fed single-frequency circularly polarized positioning antenna provided in Embodiment 1 of the present invention;

[0029] Figure 3 A schematic diagram of the structure of a dual-fed single-frequency circularly polarized positioning antenna provided in Embodiment 2 of the present invention;

[0030] Figure 4 A schematic diagram of the S parameters of a dual-fed single-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

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

[0032] Figure 6A two-dimensional four-axis ratio simulation diagram of the phi=0°, 45°, 90°, and 135° sections of the dual-fed single-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

[0033] Figure 7 A schematic diagram of the two-dimensional right-hand circular polarization gain of a dual-fed single-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

[0034] Figure 8 A schematic diagram of the structure of a single-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

[0035] Fig. 9 A schematic diagram of the structure of a dual-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

[0036] Fig.10 A schematic diagram of the S parameters of a single-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

[0037] Fig.11 A top two-dimensional axial ratio simulation diagram of the second annular radiator of the single-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention when in operation;

[0038] Fig.12 A top two-dimensional axial ratio simulation diagram of the first annular radiator in the single-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention when it is working;

[0039] Fig.13 A schematic diagram of the top two-dimensional right-hand circular polarization gain of the second annular radiator of the single-fed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention when working;

[0040] Fig.14 A schematic diagram of the top two-dimensional right-hand circular polarization gain when the first annular radiator in the single-fed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention is working;

[0041] Fig.15 A two-dimensional four-axis ratio simulation diagram of the phi=0° and 90° sections of the second annular radiator of the single-fed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention when working;

[0042] Fig.16 A two-dimensional four-axis ratio simulation diagram of the phi=0° and 90° sections when the first annular radiator in the single-fed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention is working;

[0043] Fig.17 A schematic diagram of the right-hand circular polarization gain of the second annular radiator of the single-fed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention when working;

[0044] Fig.18A schematic diagram of the right-hand circular polarization gain when the first annular radiator in the single-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention is working;

[0045] Fig.19 A schematic diagram of the S parameters of a dual-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention;

[0046] Fig. 20 A top two-dimensional axial ratio simulation diagram of the second annular radiator of the dual-feed dual-frequency circularly polarized positioning antenna provided by an embodiment of the present invention when in operation;

[0047] Fig.21 A top two-dimensional axial ratio simulation diagram of the first annular radiator in the dual-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention when it is working;

[0048] Fig. 22 A two-dimensional four-axis ratio simulation diagram of the phi=0°, 45°, 90°, and 135° sections of the second annular radiator of the dual-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention when working;

[0049] Fig.23 A two-dimensional four-axis ratio simulation diagram of the phi=0°, 45°, 90°, and 135° sections when the first annular radiator in the dual-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention is working;

[0050] Fig.24 A schematic diagram of two-dimensional right-hand circular polarization gain when the second annular radiator in the dual-feed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention is working;

[0051] Fig.25 A schematic diagram of the two-dimensional right-hand circular polarization gain when the first annular radiator in the dual-fed dual-frequency circularly polarized positioning antenna provided in an embodiment of the present invention is working. DETAILED DESCRIPTION

[0052] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying 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 being "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 being "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 position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present application.

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

[0056] See also Figure 1 and Figure 2 A circularly polarized positioning antenna that can be used for a wearable device provided in an embodiment of the present application 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., to ensure that two modes of excitation with equal amplitude and a phase difference of 90° are generated on the antenna, thereby realizing the circular polarization characteristics 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 the first feeding signal to excite the first annular radiator 10 to operate in the 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] See also Figure 1 In one embodiment, one end of the second branch 30 away from the first annular radiator 10 is used to be grounded 100 to stimulate the first annular radiator 10 to work in the second radiation mode. Figure 2 In another embodiment, the end of the second branch 30 away from the first annular radiator 10 is used to receive the second feeding signal to stimulate the first annular radiator 10 to work in the second radiation mode, and the phase difference between the first feeding signal and the second feeding signal of the AC signal is 90°. The two implementations have similar performances and can be selected according to needs when applied.

[0060] The above-mentioned circularly polarized positioning antenna and wearable device are coupled and fed through a branch, and another branch is also coupled and fed or grounded 100, thereby exciting two radiation modes of the first annular radiator 10, and 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 circumference of the first annular radiator 10 corresponds to the wavelength of the first frequency band, for example, the circumference of the first annular radiator 10 is substantially equal to the wavelength of the first frequency band, or the circumference of the first annular radiator 10 is substantially equal to 1 / 4 of the wavelength of the first frequency band, to ensure that the antenna resonates at a required frequency.

[0062] In one embodiment, the preset distance between the first branch 20 and the second branch 30 along the periphery of the first annular radiator 10 is 0.1 to 0.5 times the wavelength of the first frequency, and is generally 0.125 to 0.375 times. 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 branches are coupled to two adjacent sides of the first annular radiator 10, such as Figure 1 and Figure 2 In the solution provided in the embodiment, the first branch 20 and the second branch 30 are respectively arranged at the midpoints of two adjacent sides of the first square-shaped annular radiator 10. In this case, the antenna is better and has a good circular polarization effect.

[0063] In one embodiment, the branch and the radiator are slot-coupled for feeding, which makes matching and tuning easier. Specifically, the first branch 20 and / or the second branch 30 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 10 and a coupling gap is provided between the two, 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 an end away from the first annular radiator 10. Thus, the main body of the branch constitutes a T-shaped structure or an inverted L-shaped structure, and by adjusting the size of the branch and the spacing of the coupling gap, the coupling degree can be adjusted to achieve matching tuning of the antenna.

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

[0065] In other embodiments, the branch and the radiator are directly fed, and the first branch 20 and / or the second branch 30 both include a capacitor and a third coupling segment, 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 segment, and the second end of the third coupling segment is the end away from the first annular radiator 10. In this way, another implementation method of branches and coupling is provided, and capacitors with different capacitances can be selected to adjust the coupling degree to achieve matching tuning of the antenna. It can be understood that the first branch 20 and the second branch 30 can select the same coupling method or different coupling methods in the above two coupling methods.

[0066] See also Figure 3 In a further embodiment, in order to achieve miniaturization, a plurality of first inductance devices 40 are provided on the first annular radiator 10, and each first inductance device 40 is arranged at intervals along the circumference of the first annular radiator 10. Optionally, each first inductance device 40 is arranged at equal intervals in the circumference of the first annular radiator 10, and of course, it may not be arranged at equal intervals, and the specific arrangement can be adjusted according to actual needs. In this embodiment, the first inductance device 40 is provided 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 inductance device 40 can generally be a lumped inductor, that is, an inductor, or a serpentine curved trace.

[0067] Depend on Figure 3 It can be seen that in this embodiment, four first inductance devices 40 are provided on the first annular radiator 10, but in fact it is not limited to this. Different numbers of first inductance devices 40 can also be provided according to different size requirements. Usually, in order to achieve a good circular polarization effect, each first inductance device 40 is arranged at equal intervals in the circumferential direction of the first annular radiator 10, and each first inductance device 40 is provided at the position with the largest current, such as the midpoint position of each side of the square-shaped first annular radiator 10. The inductance value range of the first inductance device 40 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 annular radiator can be. In some cases where miniaturization is required to be high, 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 curved routing, or multiple inductors are loaded.

[0068] from Figure 4 It can be seen that the circularly polarized positioning antenna resonates at 1.575 GHz in the GPS (Global Positioning System) L1 frequency band, and the impedance bandwidth (S11<-6dB) can completely cover the entire GPS-L1 frequency band (1575±2MHz), indicating that the 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 frequency band of GPS, the axial ratio of the top of the positioning antenna (phi=0°, theta=0°) is below 5dB. When the above-mentioned positioning antenna operates in the GPS-L1 frequency band of 1.575GHz and the cross-sections are phi=0°, 45°, 90°, and 135°, in the range of θ=-60 to 60°, the axial ratio of the positioning antenna is less than 10dB, indicating that the axial ratio characteristics of the above-mentioned positioning antenna are good and meet the performance requirements of the positioning antenna.

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

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

[0072] By coupling the two annular radiators to each other, two radiation modes of the second annular radiator 50 are realized. The two radiation modes have equal amplitudes and a phase difference of 90°, and the circular polarization effect is also achieved. The two annular radiators work together to achieve dual-frequency circular polarization. When the first annular radiator 10 is required to work, a feed signal matching its working frequency is connected. When the second annular radiator 50 is required to work, a feed signal matching its working frequency is connected. In this way, the dual-frequency circularly polarized positioning antenna of this embodiment works in time-sharing mode, which can match the positioning signals of the two frequency bands and improve the positioning accuracy.

[0073] Generally, the first annular radiator 10 and the second annular radiator 50 have the same shape, and different shapes can also be set according to needs. The second annular radiator 50 is similar to the first annular radiator 10, and is a centrally symmetrical structure or an axially symmetrical 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., which ensures that two modes of excitation with equal amplitude and a phase difference of 90° are generated on the antenna, thereby realizing the circular polarization characteristics of the antenna.

[0074] In one embodiment, in order to achieve a good circular polarization effect, the center of the first annular radiator 10 and the center of the second annular radiator 50 fall on the same axis, so that the coupling degree of the two in all directions is balanced.

[0075] In one embodiment, the circumference of the second ring radiator 50 corresponds to the wavelength of the second frequency band. For example, the circumference of the second ring radiator 50 is substantially equal to the wavelength of the second frequency band, or the circumference of the second ring radiator 50 is substantially equal to 1 / 4 of the wavelength of the second frequency band, so as to ensure that the antenna resonates at the required frequency point.

[0076] See also Fig. 9 In one embodiment, in order to achieve miniaturization, a plurality of second inductance devices 60 are provided on the second ring radiator 50, and each second inductance device 60 is arranged at intervals along the circumference of the second ring radiator 50. Optionally, each second inductance device 60 is arranged at equal intervals in the circumference of the second ring radiator 50, and of course, it can also be arranged at different intervals, which can be adjusted according to actual needs. In this embodiment, the second inductance device 60 is mainly used to extend the physical length of the second ring radiator 50 to reduce the size of the positioning antenna and effectively miniaturize the antenna. Optionally, the second inductance device 60 can generally be a lumped inductor, that is, an inductor, or a serpentine curved trace.

[0077] Depend on Fig. 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 Fig.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 Fig.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 Fig.12 , 14 , 16, 18, it can be seen that the above Figure 8When the positioning antenna shown works at the L1 frequency band of GPS at 1.575 GHz, the axial ratio of the top of the positioning antenna (phi = 0°, theta = 0°) is below 3 dB, and the right-hand circular polarization gain of the top is about 2.8 dB. When the positioning antenna works at the L1 frequency band of GPS at 1.575 GHz and the 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 positioning antenna is good and meets the performance requirements of the positioning antenna. Under the condition of the same gain, the circularly polarized antenna receives satellite signals 3 dB higher than the traditional linearly polarized antenna, and the positioning effect of the positioning antenna is better than that of the traditional linearly polarized antenna.

[0082] from Fig.19 It can be seen that the above Fig. 9 The dual-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.

[0083] from Fig. 20 , 22 , 24 It can be seen that the above Fig. 9 When the positioning antenna shown works at the GPS L5 frequency band 1.176GHz, the axial ratio of the top of the positioning antenna (phi=0°, theta=0°) is below 5.6dB. When the positioning antenna works at the GPS L5 frequency band 1.176GHz and the sections are phi=0°, 45°, 90°, and 135°, within the range of θ=-60 to 60°, the axial ratio of the positioning antenna is less than 10dB, indicating that the axial ratio characteristics of the positioning antenna are good and meet the performance requirements of the positioning antenna. Fig. 9 When the positioning antenna shown works at the L5 frequency band of GPS 1.176 GHz, the right-hand circular polarization gain of the top of the positioning antenna (phi=0°, theta=0°) is about 2.4 dB. Under the condition of the same gain, the circularly polarized antenna receives satellite signals 3 dB better than the traditional linearly polarized antenna. The positioning effect of the above positioning antenna is better than that of the traditional linearly polarized antenna.

[0084] from Fig.21 , 23 , 25 It can be seen that the above Fig. 9When the positioning antenna shown works at the GPS L1 frequency band 1.575 GHz, the axial ratio of the top of the positioning antenna (phi = 0°, theta = 0°) is below 4.5 dB. When the positioning antenna works at the GPS L1 frequency band 1.575 GHz and the sections 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 characteristics of the positioning antenna are good and meet the performance requirements of the positioning antenna. Fig. 9 When the positioning antenna shown works in the L1 frequency band of GPS 1.176GHz, the right-hand circular polarization gain of the top of the positioning antenna (phi=0°, theta=0°) is about 0.9dB. Under the condition of the same gain, the circularly polarized antenna receives satellite signals 3dB better than the traditional linearly polarized antenna. The positioning effect of the above positioning antenna is better than that of the traditional linearly polarized antenna.

[0085] In addition, the present application also provides a wearable device, including a circuit board and a circularly polarized positioning antenna as described in any of the above embodiments, wherein one end of a first branch of the circularly polarized positioning antenna away from the first annular radiator is connected to a first RF port of the circuit board, and one end of a second branch of the circularly polarized positioning antenna away from the first annular radiator is connected to a second RF port of the circuit board or a ground port of the circuit board.

[0086] The embodiments described above 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 aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions 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 circular polarization positioning antenna, characterized in that: include: A first annular radiator, which operates in a first frequency band; A first branch node is coupled to the first annular radiator, wherein an end of the first branch node away from the first annular radiator is used to receive a first feeding signal to excite the first annular radiator to work in a first radiation mode; a second branch node, coupled to the first annular radiator and having a preset distance from the first branch node, wherein an end of the second branch node away from the first annular radiator is used for grounding or for connecting a second feeding signal to excite the first annular radiator to operate in a second radiation mode, and a phase difference of the first feeding signal and the second feeding signal is 90°; The first branch and / or the second branch each include a first coupling section and a second coupling section, wherein a long side of the first coupling section is directly opposite to an edge of the first annular radiator and a coupling gap is provided therebetween, a first end of the second coupling section is connected to the first coupling section, and a second end extends in a direction away from the first coupling section and serves as an end away from the first annular radiator; or, The first branch and / or the second branch both include a capacitor and a third coupling segment, one end of the capacitor is connected to the first ring radiator, and the other end is connected to the first end of the third coupling segment, and the second end of the third coupling segment serves as the end away from the first ring radiator.

2. The circularly polarized positioning antenna according to claim 1, characterized in that: It also includes a second annular radiator coupled to the first annular radiator, the second annular radiator operates in a second frequency band, and one of the first annular radiator and the second annular radiator is arranged on the periphery of the other and isolated from each other.

3. The circularly polarized positioning antenna according to claim 2, characterized in that: The center of the first annular radiator and the center of the second annular radiator fall on the same axis.

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

5. The circularly polarized positioning antenna according to claim 2, characterized in that: The circumference of the second ring-shaped radiator corresponds to the wavelength of the second frequency band.

6. The circularly polarized positioning antenna according to claim 2, characterized in that: A plurality of first inductance devices are disposed on the first annular radiator, and the inductance devices are arranged at intervals along the circumference of the first annular radiator; and / or A plurality of second inductance devices are disposed on the second annular radiator, and the second inductance devices are arranged at intervals along the circumference of the second annular radiator.

7. The circularly polarized positioning antenna according to claim 6, characterized in that: The first inductor and the second inductor are lumped inductors or distributed inductors.

8. The circularly polarized positioning antenna according to claim 1, characterized in that: The plane where the first branch node is located, the plane where the second branch node is located, and the plane where the first annular radiator is located are perpendicular to each other, or The projections of the first branch and the second branch in a direction perpendicular to the plane where the first annular radiator is located fall outside the range of the plane.

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

10. The circularly polarized positioning antenna according to any one of claims 2 to 9, characterized in that: 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 annular structures.

11. The circularly polarized positioning antenna according to any one of claims 1 to 9, characterized in that: The preset distance between the first branch and the second branch along the periphery of the first annular radiator is 0.125 to 0.375 times the wavelength of the first frequency.

12. A wearable device, characterized in that: It comprises a circuit board and a circularly polarized positioning antenna as described in any one of claims 1 to 11, wherein one end of a first branch of the circularly polarized positioning antenna away from the first ring radiator is connected to a first RF port of the circuit board, and one end of a second branch of the circularly polarized positioning antenna away from the first ring radiator is connected to a second RF port of the circuit board or a ground port of the circuit board.

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