Circular polarization positioning antenna and wearable device

Abstract

A circularly polarized positioning antenna and a wearable device, the circularly polarized positioning antenna comprising a feeding branch, having a feeding portion and a first feeding arm and a second feeding arm at an angle; a first radiating arm coupled with the first feeding arm, the first radiating arm being bent and arranged in a first clearance area extending along the arrangement direction of the first feeding arm, the first clearance area being located on one side of the first feeding arm; a second radiating arm coupled with the second feeding arm, the second radiating arm being bent and arranged in a second clearance area extending along the arrangement direction of the second feeding arm; the electrical signals on the first radiating arm and the second radiating arm satisfy equal amplitude and a phase difference of 90°, thereby realizing circularly polarized radiation, so as to reduce multipath interference, thereby effectively improving the positioning accuracy of the positioning antenna of the wearable device; being bent and arranged in the clearance area can reduce the volume of the entire antenna, which is conducive to miniaturization and easier to implement on wearable products.

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.

[0003] In addition, traditional circularly polarized antennas, such as four-arm spiral antennas, require multiple contact points to be added on the motherboard for feeding or grounding, which takes up more space on the motherboard. Summary of the invention

[0004] The purpose of this application is to provide a circularly polarized positioning antenna and a wearable device, aiming to solve the problems of low antenna positioning accuracy and large space occupied by the mainboard of existing wearable devices.

[0005] A first aspect of an embodiment of the present application provides a circularly polarized positioning antenna, comprising:

[0006] A feeding branch having a feeding portion at one end for receiving a feeding signal, a first feeding arm connected to the other end of the feeding portion, and a second feeding arm connected to the other end of the feeding portion, wherein an angle is formed between the first feeding arm and the second feeding arm;

[0007] A first radiating arm, one end of which is coupled to the first feeding arm, the first radiating arm being bent and arranged in a first clearance area, the first clearance area being located at one side of the first feeding arm and extending along an arrangement direction of the first feeding arm;

[0008] A second radiating arm, one end of which is coupled to the second feeding arm, the second radiating arm is bent and arranged in a second clearance area, the second clearance area is located on one side of the second feeding arm and extends along the arrangement direction of the second feeding arm;

[0009] When the first radiation arm and the second radiation arm resonate near the operating frequency, the electrical signals on the first radiation arm and the second radiation arm have equal amplitudes and a phase difference of 90°.

[0010] The circularly polarized positioning antenna uses a feeding branch to feed two radiating arms to form two orthogonal mode resonances, so that at the working frequency, the resonance amplitudes of the two modes are equal, the phase difference is 90°, and circularly polarized radiation is generated. When the polarization mode is right-hand circular polarization, the positioning antenna can better receive navigation satellite signals, and the right-hand circular polarization radiation generated can also filter the left-hand circular polarization 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. In addition, the monopole antenna has only one feeding point, which can reduce the space occupied by the mainboard and improve the utilization rate of the circuit board.

[0011] In one embodiment, the first radiating arm comprises:

[0012] A first coupling section is parallel to and spaced from the first feeding arm, and is directly opposite to at least a portion of the first feeding arm for coupling;

[0013] A first curved radiating section, wherein the head end of the first curved radiating section is connected to an end of the first coupling section away from the feeding portion, and the distance between the end of the first curved radiating section and the feeding portion is greater than the distance between the head end of the first curved radiating section and the feeding portion.

[0014] In one embodiment, the second radiating arm comprises:

[0015] A second coupling section is parallel and spaced from the second feeding arm and directly opposite to at least a portion of the second feeding arm for coupling;

[0016] A second curved radiating section, a starting point of the second curved radiating section is connected to an end of the second coupling section away from the feeding part, and a distance between the end of the second curved radiating section and the feeding part is greater than a distance between the head end of the second curved radiating section and the feeding part.

[0017] In one embodiment, the other end of the first radiation arm is connected to or spaced apart from the other end of the second radiation arm.

[0018] In one of the embodiments, the routing lengths of the first radiation arm and the second radiation arm correspond to 1 / 4 of the working wavelength of the circularly polarized positioning antenna, and the two are not equal in length.

[0019] In one embodiment, the first feeding arm and the second feeding arm are straight bar type.

[0020] In one embodiment, the first feeding arm and the second feeding arm are symmetrical to each other.

[0021] In one embodiment, the feeding portion, the first feeding arm and the second feeding arm are perpendicular to each other.

[0022] In one embodiment, the angle ranges from 75° to 105°.

[0023] A second aspect of an embodiment of the present application provides a wearable device, comprising the circularly polarized positioning antenna as described above.

[0024] 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

[0025] Figure 1 A schematic diagram of the structure of a circularly polarized positioning antenna provided in an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of the S parameters of the circularly polarized positioning antenna provided in an embodiment of the present invention;

[0027] Figure 3 A two-dimensional axial ratio diagram of the circularly polarized positioning antenna provided in an embodiment of the present invention is a curve of axial ratio variation with frequency at phi=65° and theta=64°;

[0028] Figure 4 A two-dimensional axial ratio diagram of the circularly polarized positioning antenna provided in an embodiment of the present invention is a curve of axial ratio variation with angle at sections of phi=40°, 65°, and 90°;

[0029] Figure 5 A three-dimensional radiation pattern of a circularly polarized positioning antenna provided in an embodiment of the present invention;

[0030] Figure 6 The two-dimensional radiation pattern of the circularly polarized positioning antenna provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] See also Figure 1 The circularly polarized positioning antenna (hereinafter referred to as the positioning antenna) that can be used for wearable devices provided in an embodiment of the present application has a dielectric substrate 100, such as a PCB board. The dielectric substrate 100 can be a ground plate, and a feeding end 101 connected to a GPS (Global Positioning System) module is provided on the dielectric substrate 100. The circularly polarized positioning antenna includes a feeding branch 11, a first radiating arm 1212 and a second radiating arm 13.

[0036] The feeding branch 11 has a feeding part 111 at one end for receiving the feeding signal output by the GPS module, a first feeding arm 112 connected to the other end of the feeding part 111, and a second feeding arm 113 connected to the other end of the feeding part 111, and there is an angle between the first feeding arm 112 and the second feeding arm 113. One end of the first radiating arm 12 is coupled with the first feeding arm 112, and the first radiating arm 12 is bent and arranged in the first clearance area 10, and the first clearance area 10 is located at one side of the first feeding arm 112 and extends along the arrangement direction (first direction) x of the first feeding arm 112; one end of the second radiating arm 13 is coupled with the second feeding arm 113, and the second radiating arm 13 is bent and arranged in the second clearance area 20, and the second clearance area 20 is located at one side of the second feeding arm 113 and extends along the arrangement direction (second direction) y of the second feeding arm 113; wherein, when the first radiating arm 12 and the second radiating arm 13 resonate near the operating frequency point, such as 1.575 GHz in the GPS L1 frequency band, or 1.760 GHz in the L5 frequency band, the electrical signals (electric fields or current signals) on the first radiating arm 12 and the second radiating arm 13 satisfy equal amplitudes and a phase difference of 90°, so as to form two orthogonal modes of resonance and generate circularly polarized radiation. In addition, the positioning antenna has only one feeding terminal, which can reduce the space occupied by the mainboard and improve the utilization rate of the circuit board.

[0037] More specifically, in Figure 1 As shown, when looking down at the front side of the dielectric substrate 100, the first radiating arm 12 needs to be located in the clockwise direction (i.e., on the right side) of the second radiating arm 13 to ensure that when the first radiating arm 12 and the second radiating arm 13 resonate near the operating frequency, the current amplitudes of the first radiating arm 12 and the second radiating arm 13 are equal, and the current phase of the second radiating arm 13 is 90° earlier than the current phase of the first radiating arm 12, thereby achieving right-handed circularly polarized radiation.

[0038] It should be noted that the clearance area of ​​the antenna is the area where the antenna ground is not laid, that is, the first radiating arm 12 and the second radiating arm 13 are arranged outside the ground plane to reduce the capacitance to the ground and reduce the impact on the antenna matching to improve the gain of the antenna. In the process of setting the positioning antenna, the matching of the entire positioning antenna can be adjusted by adjusting the length of the feeding part 111, the first feeding arm 112 and the second feeding arm 113, adjusting the coupling gap between the first feeding arm 112 and the first radiating arm 12, and adjusting the coupling gap between the second feeding arm 113 and the second radiating arm 13. Furthermore, the two radiating arms 12 and 13 are arranged in a curved manner in the clearance area, which can reduce the volume of the entire antenna, which is conducive to the miniaturization of the antenna and the miniaturization of the device for setting the antenna.

[0039] In addition, the other end of the first radiation arm 12 and the other end of the second radiation arm 13 may be connected, or may be open circuits arranged at intervals, and the circular polarization effect may also be achieved.

[0040] In some embodiments, the routing lengths of the first radiation arm 12 and the second radiation arm 13 correspond to 1 / 4 of the working wavelength of the circularly polarized positioning antenna, and the two are not equal in length. That is, the routing lengths of the first radiation arm 12 and the second radiation arm 13 are substantially equal to 1 / 4 of the working wavelength of the positioning antenna to ensure that the antenna resonates at the required frequency; and the first radiation arm 12 and the second radiation arm 13 are set to be unequal in length to ensure that the radiation of the two radiation arms achieves degenerate mode separation. In other embodiments, the routing lengths of the first radiation arm 12 and the second radiation arm 13 are substantially equal to the working wavelength of the positioning antenna.

[0041] As described above, when arranging the antenna, by controlling the length of the first radiating arm 12 and the second radiating arm 13 and controlling the phase advance or lag of the electrical signals on the first radiating arm 12 and the second radiating arm 13, right-hand circular polarization can be achieved, and better reception of satellite signals can be achieved; at the same time, because the positioning antenna is a right-hand circularly polarized antenna, the left-hand circularly polarized satellite signal reflected by a high-rise building or the ground can be filtered to reduce multipath interference; at the same time, a circularly polarized receiving antenna is used, which has a gain about 3dB higher than that of a linearly polarized antenna, thereby achieving a better positioning effect.

[0042] In one embodiment, the first feed arm 112 and the second feed arm 113 are generally arranged in a straight line. In other embodiments, it is understood that due to the limitation of the equipment space, the first feed arm 112 and / or the second feed arm 113 may be bent in a certain arc in the actual arrangement, but it does not affect the arrangement in one direction. In addition, the first feed arm 112 and / or the second feed arm 113 can also extend other branches outside the main body to help increase the gain, axial ratio and other performance of the antenna, for example, branches are arranged in a direction perpendicular to the dielectric substrate 100, and branches are arranged parallel to the dielectric substrate 100.

[0043] Optionally, there is an angle a between the first feeding arm 112 and the second feeding arm 113, that is, between the first direction x and the second direction y, and the range of the angle a is 70° to 110°. By respectively arranging the first radiating arm 12 and the second radiating arm 13 in the clearance areas of the two directions x and y forming the angle a, when the first radiating arm 12 and the second radiating arm 13 resonate near the operating frequency, two orthogonal modes of resonance are formed to generate good circularly polarized radiation. Relatively speaking, the circularly polarized radiation is better when the angle a is in the range of 75° to 105°.

[0044] In one embodiment, the first feeding arm 112 and the second feeding arm 113 are perpendicular to each other, that is, the angle a is 90°. In this way, the angle formed by the arrangement directions of the first radiating arm 12 and the second radiating arm 13 is also 90°, so that the two radiating arms achieve equal amplitude orthogonal resonance when feeding, and achieve good circular polarization radiation. It can be understood that due to the limitation of the equipment space, the feeding part 111 can be perpendicular or non-perpendicular to the first feeding arm 112 and the second feeding arm 113, but it is at a certain angle to the plane where the first feeding arm 112 and the second feeding arm 113 are located, which does not affect the feeding of the two feeding arms; in addition, the dielectric substrate 100 can also be parallel to the plane, and the feeding part 111 can also be perpendicular or non-perpendicular to the dielectric substrate 100. In addition, the first feeding arm 112 and the second feeding arm 113 can be symmetrical to each other, or they can be of different lengths.

[0045] In one embodiment, the first radiating arm 12 includes a first coupling segment 121 and a first bending radiating segment 122 ; the second radiating arm 13 includes a second coupling segment 131 and a second bending radiating segment 132 .

[0046] One end of the first coupling section 121 close to the feeding portion 111 is one end of the first radiating arm 12, the first coupling section 121 is parallel and spaced apart from the first feeding arm 112, and is directly opposite to at least a portion of the first feeding arm 112 for coupling; one end of the second coupling section 131 close to the feeding portion 111 is one end of the second radiating arm 13, the second coupling section 131 is parallel and spaced apart from the second feeding arm 113, and is directly opposite to at least a portion of the second feeding arm 113 for coupling, and the matching of the antenna can be adjusted by adjusting the coupling gap between the coupling section and the feeding arm and the directly opposite length.

[0047] The head end of the first bent radiating section 122 is connected to the end of the first coupling section 121 away from the feeding part 111, and the end of the first bent radiating section 122 is the other end of the first radiating arm 12, and the distance between it and the feeding part 111 is greater than the distance between the head end of the first bent radiating section 122 and the feeding part 111; the starting point of the second bent radiating section 132 is connected to the end of the second coupling section 131 away from the feeding part 111, and the end of the second bent radiating section 132 is the other end of the second radiating arm 13, and the distance between it and the feeding part 111 is greater than the distance between the head end of the second bent radiating section 132 and the feeding part 111. It can be understood that in order to ensure that the electrical signals on the first radiation arm 12 and the second radiation arm 13 have equal amplitudes and a phase difference of 90° to form two orthogonal modes of resonance, the first bent radiation section 122 and the second bent radiation section 132 are basically symmetrical, with only a certain length difference of about 1 / 4 of the working wavelength.

[0048] In general, the first curved radiant section 122 and the second curved radiant section 132 are curved lines that connect one or more planes in a curved manner. In this embodiment, the first curved radiant section 122 encloses a rectangular space 10a on the first clearance area 10 along the first direction x, and the second curved radiant section 132 encloses a rectangular space 20a on the second clearance area 20 along the second direction y. In other embodiments, the space 10a and the space 20a enclosed by the first curved radiant section 122 and the second curved radiant section 132 may be cylindrical, elliptical, or multifaceted. Alternatively, in some embodiments, the first curved radiant section 122 and the second curved radiant section 132 are curved lines that are serpentine along a plane.

[0049] In one embodiment, the first radiation arm 12 and / or the second radiation arm 13 are loaded with an inductor (not shown), wherein the inductor is a lumped inductor or a distributed inductor. The inductor is a lumped inductor or a distributed inductor. The inductor is mainly used to increase the equivalent length of the first antenna, so as to reduce the size of the positioning antenna and effectively miniaturize the antenna; optionally, the inductor can generally be a lumped inductor, i.e., an inductor, or a serpentine curved trace.

[0050] from Figure 2 It can be seen that the circularly polarized positioning antenna resonates at 1.575 GHz, and the impedance bandwidth (S11<-6 dB) can completely cover the entire GPS-L1 frequency band (1575±2 MHz), indicating that the positioning antenna has good reception of navigation satellite signals.

[0051] from Figure 3 It can be seen that the above positioning antenna can achieve the best circular polarization performance (i.e., the minimum axial ratio) at a specific spatial angle (theta=64°, phi=65°). In the GPS L1 frequency band, the axial ratio is <1dB, indicating that the axial ratio characteristics of the above positioning antenna are very good and meet the performance requirements of the positioning antenna.

[0052] from Figure 4 It can be seen that when the above-mentioned positioning antenna operates in the GPS-L1 frequency band of 1.575 GHz and the sections are phi = 40°, 65°, and 90°, in the range of θ = 5° to 75°, the axial ratio of the positioning antenna is less than 10 dB, indicating that the axial ratio characteristics of the above-mentioned positioning antenna are good and meet the performance requirements of the positioning antenna.

[0053] from Figure 5 and Figure 6It can be seen that when the above-mentioned positioning antenna operates in the GPS-L1 frequency band of 1.575GHz, the positioning antenna achieves a maximum right-hand circular polarization directivity coefficient of 1.59dB at a certain position (phi=90°, theta=30°). Under the same directivity coefficient, the satellite signal received by the circularly polarized antenna is 3dB higher than that received by the linearly polarized antenna. At the same time, it has a suppression function for interference signals. Therefore, the positioning effect of the above-mentioned positioning antenna is better than that of the traditional linearly polarized antenna.

[0054] A second aspect of an embodiment of the present application provides a wearable device, comprising the circularly polarized positioning antenna as described above.

[0055] 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 repeated here one by one. The above-mentioned wearable device positioning antenna can better receive navigation satellite signals, and the right-handed circularly polarized radiation generated 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. In wearable devices, the space of the motherboard is relatively limited. Traditional circularly polarized antennas such as four-arm spirals need to add multiple contact points on the motherboard for feeding or grounding, which takes up more space on the motherboard. Realizing the positioning antenna in the form of a monopole can reduce the space occupied by the antenna on the motherboard.

[0056] 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 feeding branch having a feeding portion at one end for receiving a feeding signal, a first feeding arm connected to the other end of the feeding portion, and a second feeding arm connected to the other end of the feeding portion, wherein an angle is formed between the first feeding arm and the second feeding arm; A first radiating arm, one end of which is coupled to the first feeding arm, the first radiating arm being bent and arranged in a first clearance area, the first clearance area being located at one side of the first feeding arm and extending along the arrangement direction of the first feeding arm; the first radiating arm comprising a first bent radiating section; A second radiating arm, one end of which is coupled to the second feeding arm, the second radiating arm is bent and arranged in a second clearance area, the second clearance area is located on one side of the second feeding arm and extends along the arrangement direction of the second feeding arm; the second radiating arm includes a second bent radiating section; When the first radiation arm and the second radiation arm resonate near the operating frequency, the electrical signals on the first radiation arm and the second radiation arm have equal amplitudes and a phase difference of 90°; The first curved radiant section encloses a rectangular space on the first clearance area along a first direction, and the second curved radiant section encloses a rectangular space on the second clearance area along a second direction, and the first direction and the second direction form an angle of 70° to 110°.

2. The circularly polarized positioning antenna according to claim 1, characterized in that: The first radiating arm further comprises: A first coupling section is parallel to and spaced from the first feeding arm, and is directly opposite to at least a portion of the first feeding arm for coupling; The head end of the first curved radiating section is connected to an end of the first coupling section away from the feeding portion, and the distance between the end of the first curved radiating section and the feeding portion is greater than the distance between the head end of the first curved radiating section and the feeding portion.

3. The circularly polarized positioning antenna according to claim 1, characterized in that: The second radiating arm further comprises: A second coupling section is parallel and spaced from the second feeding arm and directly opposite to at least a portion of the second feeding arm for coupling; The starting point of the second curved radiating section is connected to an end of the second coupling section away from the feeding part, and the distance between the end of the second curved radiating section and the feeding part is greater than the distance between the beginning of the second curved radiating section and the feeding part.

4. The circularly polarized positioning antenna according to any one of claims 1 to 3, characterized in that: The other end of the first radiation arm is connected to or spaced apart from the other end of the second radiation arm.

5. The circularly polarized positioning antenna according to any one of claims 1 to 3, characterized in that: The routing lengths of the first radiation arm and the second radiation arm correspond to 1 / 4 of the working wavelength of the circularly polarized positioning antenna, and the two are not of equal length.

6. The circularly polarized positioning antenna according to any one of claims 1 to 3, characterized in that: The first feeding arm and the second feeding arm are straight bar type.

7. The circularly polarized positioning antenna according to any one of claims 1 to 3, characterized in that: The first feeding arm and the second feeding arm are symmetrical to each other.

8. The circularly polarized positioning antenna according to any one of claims 1 to 3, characterized in that: The feeding portion, the first feeding arm and the second feeding arm are perpendicular to each other.

9. The circularly polarized positioning antenna according to any one of claims 1 to 3, characterized in that: The angle between the first feeding arm and the second feeding arm ranges from 75° to 105°.

10. A wearable device, characterized in that: It comprises the circularly polarized positioning antenna as described in any one of claims 1 to 9.

Images