Circularly polarized antennas and navigation equipment

Abstract

The present application relates to a circularly polarized antenna and navigation equipment, wherein a broadband power splitter is electrically connected to a feed network, the broadband power splitter is electrically connected to the feed network, the feed network is electrically connected to a second radiating unit, and the second radiating unit is coupled to a first radiating unit. The first radiating unit comprises a low-frequency annular radiator and a high-frequency annular radiator, the low-frequency annular radiator and the high-frequency annular radiator being concentric annular, and the low-frequency annular radiator having a slow-wave structure. Based on this structure, the circularly polarized antenna achieves full navigation frequency band coverage. Furthermore, this structure allows the antenna to maintain low frequency while reducing its size, thereby miniaturizing the entire circularly polarized antenna.

Description

Technical Field

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

[0002] The Global Navigation Satellite System (GNSS) is a satellite-based radio navigation system.

[0003] Generally speaking, in order to better receive GNSS signals, the design of navigation and positioning antennas needs to meet many stringent requirements in many aspects. However, the existing technology lacks an antenna with small size and ultra-wideband coverage. Summary of the Invention

[0004] Based on this, it is necessary to provide a circularly polarized antenna and navigation equipment to address the above technical problems, which can achieve ultra-wideband coverage while reducing the antenna size.

[0005] In a first aspect, the present application provides a circularly polarized antenna, comprising a first radiating element, a second radiating element, a feed network, and a broadband power splitter arranged from top to bottom; the broadband power splitter is electrically connected to the feed network, the feed network is electrically connected to the second radiating element, and the second radiating element is coupled to the first radiating element;

[0006] The broadband power splitter is used to convert the received radio frequency signal into four sub-signals that meet the circular polarization requirements; the feeding network is used to feed the four sub-signals into the second radiating unit, so that the second radiating unit is coupled with the first radiating unit for feeding;

[0007] Among them, the first radiating unit includes a low-frequency annular radiator and a high-frequency annular radiator. The low-frequency annular radiator and the high-frequency annular radiator are concentric rings, and the low-frequency annular radiator is a slow-wave structure. The bandwidth corresponding to the frequency generated by the low-frequency annular radiator and the high-frequency annular radiator during coupling feeding is greater than or equal to the full-band navigation bandwidth.

[0008] In one embodiment, the slow-wave structure is in the shape of a broken line, and the spacing between adjacent broken points on the broken line is 1 mm.

[0009] In one embodiment, the inner diameter of the low-frequency annular radiation plate is 50 mm, and the outer diameter of the low-frequency annular radiation plate is 56.8 mm; the inner diameter of the high-frequency annular radiation plate is 34 mm, and the outer diameter of the high-frequency annular radiation plate is 42 mm.

[0010] In one embodiment, the low-frequency annular radiation plate and the high-frequency annular radiation plate are laid on the upper surface of the first printed circuit board.

[0011] In one embodiment, the second radiation unit includes four radiation patches with groove structures, and the four radiation patches with notch structures are symmetrically laid on the upper surface of the second printed circuit board, and a gap of a preset size is separated between two adjacent radiation patches.

[0012] In one embodiment, the radiation patch with the groove structure is a W-shaped radiation patch or a U-shaped radiation patch.

[0013] In one embodiment, the preset size is 8.73 mm.

[0014] In one embodiment, the diameter of the first printed circuit board is 84 mm, the diameter of the second printed circuit board is 120 mm, and the height between the first printed circuit board and the second printed circuit board is 7 mm.

[0015] In one embodiment, the feeding network includes four feeding plates; the four feeding plates are laid on the lower surface of the second printed circuit board and are correspondingly located directly below the gaps between the radiation patches.

[0016] In one embodiment, the feeding plate has a length of 13 mm and a width of 3 mm.

[0017] In one embodiment, the feed network further comprises four feed assemblies, each feed sheet comprising a feed point extending from the upper surface to the lower surface of the second printed circuit board;

[0018] The upper end of each feeding component passes through a feeding point and reaches the upper surface of the second printed circuit board, and the lower end of each feeding component is connected to the broadband power dividing unit.

[0019] In one embodiment, the feeding component is a feeding needle, and the length of the feeding needle is 13 mm.

[0020] In one embodiment, the broadband power division unit includes a broadband power division network and a third printed circuit board. The broadband power division network is laid on the lower surface of the third printed circuit board, and the lower ends of the four feeding components pass through the third printed circuit board to connect to the broadband power division network.

[0021] In one embodiment, the diameter of the third printed circuit board is 150 mm, and the height between the third printed circuit board and the second printed circuit board is 13 mm.

[0022] In a second aspect, the present application provides a navigation device, which includes the circularly polarized antenna provided by any one of the embodiments of the first aspect above.

[0023] The circularly polarized antenna and navigation equipment provided in the present application are characterized in that the broadband power splitter unit is electrically connected to the feeding network, the broadband power splitter unit is electrically connected to the feeding network, the feeding network is electrically connected to the second radiating unit, and the second radiating unit is coupled to the first radiating unit; wherein, the first radiating unit includes a low-frequency annular radiating plate and a high-frequency annular radiating plate, the low-frequency annular radiating plate and the high-frequency annular radiating plate are concentric rings, and the low-frequency annular radiating plate is a slow-wave structure. Based on this structure, the broadband power splitter is used to convert the received RF signal into a four-way sub-signal that meets the circular polarization requirements; the feeding network is used to feed the four-way sub-signal into the second radiating unit so that the second radiating unit is coupled and fed with the first radiating unit. In this way, the bandwidth corresponding to the frequency generated by the low-frequency annular radiator and the high-frequency annular radiator in the first radiating unit during coupling feeding is greater than or equal to the full-band navigation bandwidth. In the entire process, because the broadband power splitter is used to convert the received RF signal into a four-way sub-signal that meets the circular polarization requirements, the subsequent feeding network, the second radiating unit and the first radiating unit are all carried out for the four-way sub-signal that meets the circular polarization requirements. After the second radiating unit and the first radiating unit are coupled and fed, two low-frequency and high-frequency annular radiating patches are provided in the first radiating unit, thereby increasing the bandwidth of the antenna radiation signal. Since the bandwidth needs to be greater than or equal to the full-band navigation bandwidth, the circularly polarized antenna covers the full-band navigation band. In addition, because the low-frequency annular radiation plate in the first radiation unit adopts a slow-wave structure, this structure can reduce the size of the antenna while ensuring the low frequency, thereby miniaturizing the entire circularly polarized antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is a schematic diagram of the structure of a circularly polarized antenna in one embodiment;

[0025] Figure 2 is a schematic diagram of a concentric double-ring radiating patch in a first radiating unit in one embodiment;

[0026] Figure 3 is a schematic diagram of a radiation patch with a groove structure in the second radiation unit in one embodiment;

[0027] Figure 4 is a schematic diagram of a W-shaped radiation patch in a second radiation unit in one embodiment;

[0028] Figure 5 Schematic diagram of a feed sheet in a feed network in one embodiment;

[0029] Figure 6 is a schematic cross-sectional view of an antenna array in one embodiment;

[0030] Figure 7 is a schematic diagram of a feeding point in a feeding network in one embodiment;

[0031] Figure 8 1 is a schematic diagram of a broadband power division network according to an embodiment of the present invention;

[0032] Figure 9 FIG1 is a schematic diagram of a broadband power splitter network on a printed circuit board in one embodiment;

[0033] Figure 10 Schematic diagram of standing wave simulation results of a broadband power splitter network in one embodiment;

[0034] Figure 11 is a schematic cross-sectional view of an antenna element in another embodiment;

[0035] Figure 12 is an overall schematic diagram of an antenna in one embodiment;

[0036] Figure 13 A schematic diagram of screw holes in a printed circuit board in one embodiment;

[0037] Figure 14 Schematic diagram of antenna gain simulation results in one embodiment;

[0038] Figure 15 Schematic diagram of the simulation results of antenna low elevation gain in one embodiment;

[0039] Figure 16 Schematic diagram of antenna axial ratio simulation results in one embodiment;

[0040] Description of reference numerals:

[0041] 10: first radiation unit; 20: second radiation unit;

[0042] 30: Feed network; 40: Broadband power splitter unit;

[0043] 50: screw; 60: medium support column;

[0044] 101: low frequency annular radiator; 102: high frequency annular radiator;

[0045] 103: a first printed circuit board; 201: a radiation patch with a groove structure;

[0046] 202: second printed circuit board; 301: feed plate;

[0047] 302: feeding component; 3011: feeding point;

[0048] 401: broadband power distribution network; 402: third printed circuit board. DETAILED DESCRIPTION

[0049] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0050] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0052] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0053] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0054] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0055] Specifically, see Figure 1 , Figure 1 The main schematic diagram of a circularly polarized antenna in an embodiment of the present application is shown, which includes a first radiating unit 10, a second radiating unit 20, a feeding network 30 and a broadband power splitter unit 40 arranged from top to bottom; the broadband power splitter unit 40 is electrically connected to the feeding network 30, the feeding network 30 is electrically connected to the second radiating unit 20, and the second radiating unit 20 is coupled to the first radiating unit 10; the broadband power splitter unit 40 is used to convert the received RF signal into a four-way sub-signal that meets the circular polarization requirements; the feeding network 30 is used to feed the four-way sub-signal into the second radiating unit 20, so that the second radiating unit 20 is coupled and fed with the first radiating unit 10; wherein, the first radiating unit 10 includes a low-frequency annular radiation plate 101 and a high-frequency annular radiation plate 102, the low-frequency annular radiation plate 101 and the high-frequency annular radiation plate 102 are concentric annular, and the low-frequency annular radiation plate 101 is a slow-wave structure, and the bandwidth corresponding to the frequency generated by the low-frequency annular radiation plate 101 and the high-frequency annular radiation plate 102 during coupling feeding is greater than or equal to the full-band navigation bandwidth.

[0056] In an embodiment of the present application, the first radiating unit 10, the second radiating unit 20, the feeding network 30 and the broadband power splitter unit 40 are arranged in sequence from top to bottom; optionally, when arranged from top to bottom, the geometric centers of the first radiating unit 10, the second radiating unit 20, the feeding network 30 and the broadband power splitter unit 40 are located on the same straight line.

[0057] Continue to see Figure 1 The broadband power splitter unit 40 is connected to the feeding network 30 for feeding, the feeding network 30 is also connected to the second radiating unit 20 for feeding, and the second radiating unit 20 and the first radiating unit 10 are coupled or electrically coupled.

[0058] There is a preset interval between the first radiating element 10 and the second radiating element 20, and there is also a preset interval between the feed network 30 and the broadband power splitter unit 40. The specific values ​​of these two preset intervals are not limited in this embodiment of the application and can be determined based on actual conditions. A substrate separates the second radiating element 20 and the feed network 30, i.e., the second radiating element 20 and the feed network 30 are the front and back surfaces of the same substrate.

[0059] Based on the above connection structure, the second radiation unit 20 is coupled and fed with the first radiation unit 10. Specifically, after the RF signal enters the broadband power splitter unit 40, the broadband power splitter unit 40 converts the received RF signal into a four-way sub-signal that meets the circular polarization requirement. Because the broadband power splitter unit 40 is connected to the feeding network, the four-way sub-signal will be fed into the feeding network 30. The feeding network 30 is also connected to the second radiation unit 20, so the feeding network continues to feed the four-way sub-signal into the second radiation unit 20, and the second radiation unit 20 and the first radiation unit 10 are coupled and fed. Thus, the second radiation unit 20 couples the four-way sub-signal into the first radiation unit 10, and the first radiation unit 10 converts the signal into an electromagnetic wave signal and transmits it into space. Alternatively, based on Figure 1 The structure can also receive electromagnetic wave signals in space. The process of receiving electromagnetic wave signals is completely opposite to the process of transmitting electromagnetic wave signals, which will not be described in detail here.

[0060] Continue to see Figure 1 The first radiating element 10 includes a low-frequency annular radiator 101 and a high-frequency annular radiator 102. The low-frequency annular radiator 101 and the high-frequency annular radiator 102 are concentric annular shapes, and the low-frequency annular radiator 101 has a slow-wave structure. A slow-wave structure is a structure for implementing electromagnetic waves. Generally, when implementing an antenna, for the same size, a radiator made with a slow-wave structure extends the current path length, resulting in a lower frequency.

[0061] The bandwidth corresponding to the frequency generated by the low-frequency annular radiator 101 and the high-frequency annular radiator 102 during coupling feeding is greater than or equal to the full-band navigation bandwidth.

[0062] Specifically, when the feed network 30 feeds the four-path sub-signals into the second radiating element 20, and the second radiating element 20 couples the signals to the first radiating element 10, the low-frequency annular radiating plate 101 generates a first resonance point under the excitation of the coupled signal, and simultaneously, the high-frequency annular radiating plate 102 generates a second resonance point under the excitation of the signal. The first resonance point and the second resonance point are different resonance points, and the frequency of the first resonance point is lower than the frequency of the second resonance point.

[0063] In order to achieve full-band coverage of satellite navigation, based on the above structure, in the actual simulation process, it is necessary to make the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point greater than or equal to the full-band bandwidth of navigation. In actual applications, the radiation area of ​​the first radiation unit 10, the second radiation unit 20, the feeding network 30, and other parameters such as the spacing between each other can be adjusted to ensure that the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point is greater than or equal to the full-band bandwidth of navigation. Among them, the full-band bandwidth of navigation, that is, the full-band bandwidth of satellite navigation, is 1.1-1.7GHz. If the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point is greater than or equal to the full-band bandwidth of navigation, it can be ensured that the circularly polarized antenna feeds the signal to the second radiation unit 20 through the feeding network 30, and the electromagnetic waves radiated by the second radiation unit 20 and the first radiation unit 10 coupled and fed can cover the full-band bandwidth of satellite navigation.

[0064] In the circularly polarized antenna provided in an embodiment of the present application, the broadband power splitter unit 40 is electrically connected to the feeding network 30, the feeding network 30 is electrically connected to the second radiating unit 20, and the second radiating unit 20 is coupled to the first radiating unit 10; wherein, the first radiating unit 10 includes a low-frequency annular radiating plate 101 and a high-frequency annular radiating plate 102, the low-frequency annular radiating plate 101 and the high-frequency annular radiating plate 102 are concentric rings, and the low-frequency annular radiating plate 101 is a slow-wave structure. Based on this structure, the broadband power splitter unit 40 can convert the received RF signal into a four-way sub-signal that meets the circular polarization requirements; the feeding network 30 can feed the four-way sub-signal into the second radiating unit 20, so that the second radiating unit 20 is coupled and fed with the first radiating unit 10. In this way, the bandwidth corresponding to the frequency generated by the low-frequency annular radiator 101 and the high-frequency annular radiator 102 in the first radiating unit 10 during coupling feeding is greater than or equal to the full-band navigation bandwidth. In the entire process, because the broadband power splitter unit 40 converts the received RF signal into a four-way sub-signal that meets the circular polarization requirements, the subsequent feeding network 30, the second radiating unit 20 and the first radiating unit 10 are all transmitted with the four-way sub-signal that meets the circular polarization requirements. After the second radiating unit 20 and the first radiating unit 10 are coupled and fed, two low-frequency and high-frequency annular radiating patches are provided in the first radiating unit 10, thereby increasing the bandwidth of the antenna radiation signal. Since the bandwidth needs to be greater than or equal to the full-band navigation bandwidth, the circularly polarized antenna covers the full-band navigation band. In addition, because the low-frequency annular radiation plate 101 in the first radiation unit 10 adopts a slow-wave structure, this structure can reduce the size of the antenna while ensuring low frequency, thereby miniaturizing the entire circularly polarized antenna.

[0065] The connection method between the various components in the circularly polarized antenna and the implementation structure of each component are described below through specific embodiments.

[0066] The slow wave structure of the low frequency annular radiation plate 101 is described in detail. In one embodiment, Figure 2 As shown, the slow-wave structure is in the shape of a broken line, and the spacing between adjacent inflection points on the broken line is 1 mm.

[0067] in, Figure 2 The arrow points to a partially enlarged schematic diagram of the slow-wave structure. The spacing L1 between adjacent inflection points on the broken line shape is 1mm, and the depth L2 of the concave surface of the broken line is also 1mm. It should be noted that the spacing between all adjacent inflection points and the depth of the concave surface in the broken line structure are 1mm. Figure 2 For the sake of clarity, the dimensions are marked in two intervals.

[0068] Optionally, the low-frequency annular radiation plate 101 and the high-frequency annular radiation plate 102 are both laid on the upper surface of the first printed circuit board 103. Figure 2 and Figure 1 , Figure 2 The first printed circuit board 103 is Figure 1 The upper middle layer of the substrate, that is, the upper surface (front) of the first printed circuit board 103 is printed with a concentric double-ring low-frequency ring radiation plate 101 and a high-frequency ring radiation plate 102, and the lower surface (back) of the first printed circuit board 103 is not printed with anything.

[0069] In one embodiment, the inner diameter of the low-frequency annular radiator 101 is 50 mm, and the outer diameter of the low-frequency annular radiator 101 is 56.8 mm; the inner diameter of the high-frequency annular radiator 102 is 34 mm, and the outer diameter of the high-frequency annular radiator 102 is 42 mm. For the low-frequency annular radiator 101, its inner diameter and outer diameter both refer to the circle on which the convex surface of the broken line is located.

[0070] Based on the above diameter data, the radiation area S of the high-frequency annular radiation plate 102 can be calculated as follows: 2 Similarly, the radiation area of ​​the low-frequency annular radiation plate 101 can be calculated as S = π*((56.8-50) / 2) 2 -1*1*N, where N is the number of spacings in the polyline structure; for example, Figure 2 Taking the local enlarged view pointed by the middle arrow as an example, the number of visible spacings in the local enlarged view is 4. Of course, in the specific implementation structure, the number of spacings in the broken line structure of the low-frequency annular radiation plate 101 shall be based on its actual situation, and the embodiment of this application does not limit it.

[0071] like Figure 3As shown, the second radiation unit 20 is described. In one embodiment, the second radiation unit 20 includes four radiation patches 201 with groove structures, and the four radiation patches 201 with groove structures are symmetrically laid on the upper surface of the second printed circuit board 202, and there is a gap of a preset size between two adjacent radiation patches 201.

[0072] in, Figure 3 The four groove-structured radiation patches 201 are only an example and are not necessarily limited to this in actual application. The four groove-structured radiation patches 201 are symmetrically arranged on the second printed circuit board 202. Figure 3 and Figure 1 From the perspective of the second printed circuit board 202, Figure 1 Regarding the second layer substrate (i.e., the middle layer substrate), it should be noted that the radiation patch 201 with four groove structures is printed on the upper surface (i.e., the front surface) of the second printed circuit board 202, while the feeding network 30 is printed on the lower surface (i.e., the back surface) of the second printed circuit board 202, that is, the second radiation unit 20 and the feeding network 30 share the same substrate.

[0073] Among the radiation patches 201 with four groove structures, there is a preset size gap between two adjacent radiation patches 201. Optionally, the preset size can be 8.73 mm. Figure 3 L3 shown in the figure is the gap between two adjacent radiation patches 201.

[0074] In one embodiment, the radiation patch 201 with four groove structures is a W-shaped radiation patch or a U-shaped radiation patch. Figure 4 As shown, taking the W-shaped radiation patches as an example, there is a gap L3 between the four W-shaped radiation patches, and the four W-shaped radiation patches are symmetrically arranged on the front side of the second printed circuit board 202 .

[0075] As mentioned above, the feed network 30 is printed on the lower surface (ie, the back surface) of the second printed circuit board 202. Figure 5 FIG2 is a schematic diagram of a feed network 30 printed on the back side of the second printed circuit board 202. In one embodiment, the feed network 30 includes four feed pads 301, which are laid directly below the gaps between corresponding radiating patches on the lower surface of the second printed circuit board 202. In other words, each feed pad 301 corresponds to a gap, and each feed pad 301 is located directly below the corresponding gap.

[0076] like Figure 5 The position of each feeding plate 301 is located at Figure 4However, the size of the feed plate 301 is not required to be exactly the same as the size of the gap L3. The actual sizes of the two can be determined based on actual needs. Figure 5 The dimensions of one of the feed plates are illustrated in FIG. 1 , where the length of the feed plate is 13 mm and the width is 3 mm.

[0077] In order to realize the feeding connection between the feeding network 30 and the broadband power splitter unit 40, as shown in FIG. Figure 6 As shown, in one embodiment, the feeding network 30 further includes four feeding components 302, each feeding plate 301 includes a feeding point 3011 that passes through the upper surface to the lower surface of the second printed circuit board 202; the upper end of each feeding component 302 passes through a feeding point 3011 to reach the upper surface of the second printed circuit board 202, and the lower end of each feeding component 302 is connected to the broadband power splitter unit 40.

[0078] It should be noted that Figure 6 This is a cross-sectional view of the antenna, so Figure 6 The feeding assembly 302 and feeding plate 301 shown in FIG are not all the components and feeding plates. Figure 6 It can be seen that the four feed needle assemblies 302 and the four feed plates 301 are connected one to one, that is, one feed assembly 302 is connected to one feed plate 301, and each feed assembly 302 is connected to the feeding point of the corresponding feed plate 301. In this way, each feed assembly 302 and the corresponding feed plate 301 are connected to form an L-shaped probe. The four symmetrically arranged L-shaped probes can ensure the circular polarization characteristics of the antenna.

[0079] Among them, after each feeding component 302 is connected to the feeding point of the corresponding feeding plate 301, it will pass through the second printed circuit board 202, that is, from the feeding point on the lower surface of the second printed circuit board 202 through the second printed circuit board 202 to the upper surface of the second printed circuit board.

[0080] like Figure 7 As shown, FIG (a) schematically shows the front side of the second printed circuit board 202, and FIG (b) schematically shows the back side of the second printed circuit board 202. Figure 7 It can be seen that the feeding points 3011 on the four feeding sheets 301 extend from the back to the front, so the four feeding components 302, after being connected to the feeding points 3011 of the corresponding feeding sheets 301, will reach the front of the second printed circuit board 202. Of course, it is understood that in order to ensure the firmness of the connection, the four feeding components 302 will be welded and fixed to form feeding pads after reaching the front of the second printed circuit board 202. That is, the pad formed on the front 3011 after the feeding components 302 are welded is called a feeding pad. In actual applications, the diameter of the feeding pad can be 1 mm.

[0081] In one embodiment, the feeding component is a feeding needle, and the length of the feeding needle is 13 mm. The feeding needle can be implemented by a metal rod.

[0082] From the above Figure 6 It can be seen that the broadband power splitter unit 40 includes a broadband power splitter network 401 and a third printed circuit board 402 , wherein the broadband power splitter network 401 is laid on the lower surface of the third printed circuit board 402 .

[0083] like Figure 8 The figure shows the implementation principle diagram of the broadband power division network. Taking the Wilkinson power divider as an example, the broadband power division network 401 includes an input port Input and four output ports. When transmitting a signal, the RF signal received by the broadband power division network 401 enters from the input port Input, is divided into two paths after passing through the Wilkinson power divider, and then each path is divided into ports with different phases: 0°, 90°, 180°, and 270° after passing through the Wilkinson power divider. In this way, the design of 4 feeding phases can ensure the high precision and circular polarization characteristics of the antenna, and the highly symmetrical structure makes the axis of the satellite navigation antenna relatively small, with high circular polarization performance, thereby increasing the accuracy of the satellite navigation antenna.

[0084] With the above Figure 6 Taking the broadband power splitting network 401 shown in FIG. 4 as an example, when the broadband power splitting network 401 is implemented on the back of the third printed circuit board 402, the layout is as follows: Figure 9 As shown, Figure 9 A, B, C, and D correspond to the four phase feed points of 0°, 90°, 180°, and 270°. The four feed points are isolated from each other by isolation resistors R1, R2, and R3. Optionally, R1 = R2 = R3 = 100Ω.

[0085] The four-way signals of the feeding network 30 are fed from the broadband power division network 401. Therefore, in order to ensure the expansion of the bandwidth of the broadband power division network 401, Figure 9 In the broadband power division network 401 segment, two-stage matching segments are used, namely Figure 9 The thick and thin lines in the figure represent different levels of matching segments, thereby achieving a wider bandwidth of the broadband power division network 401.

[0086] like Figure 10 As shown above Figure 9 The data after network simulation of the implementation layout of the medium-broadband power division network 401 can be found in Figure 10 As shown in the dotted box in FIG, the standing wave is less than 1.3 in the 1.1 to 1.7 GHz frequency band (full navigation frequency band), so it meets the design indicators.

[0087] Because the broadband power splitter network 401 has four output ports A, B, C, and D, when the four feeding components 302 in the feeding network 30 are connected to the broadband power splitter unit 40, they are actually connected to the four ports A, B, C, and D of the broadband power splitter network 401 in the broadband power splitter unit 40.

[0088] Specifically, if Figure 11 The figure shows a cross-sectional view of the antenna from a low-angle perspective. There are four feeding points on the front of the third printed circuit board 402, corresponding to the four ports of the broadband power splitting network 401 on the back. That is, the four feeding components 302 in the feeding network 30 are connected to the third printed circuit board 402 at the four feeding points on the front of the third printed circuit board 402 (the circled positions in the figure), and then pass through the third printed circuit board 402 to reach the four ports A, B, C, and D of the broadband power splitting network 401 on the back, thereby achieving corresponding connections.

[0089] The sizes of the first printed circuit board 103, the second printed circuit board 202, and the third printed circuit board 402 increase in order. In one embodiment, the diameter of the first printed circuit board 103 is 84 mm, the diameter of the second printed circuit board 202 is 120 mm, and the diameter of the third printed circuit board 402 is 150 mm.

[0090] Furthermore, there is a preset gap between the first printed circuit board 103, the second printed circuit board 202, and the third printed circuit board 402, that is, all three are arranged in space. Specifically, the height between the first printed circuit board 103 and the second printed circuit board 202 is 7 mm, and the height between the third printed circuit board 402 and the second printed circuit board 202 is 13 mm.

[0091] To further clarify the relationship between the first radiation unit 10, the second radiation unit 20, the feed network 30, and the broadband power splitter unit 40, see Figure 12 The overall schematic diagram of the antenna provided, where: Figure 12 Only visible parts are marked.

[0092] Among them, because the first printed circuit board 103, the second printed circuit board 202, and the third printed circuit board 402 are spaced apart, that is, there is air between the three, so in order to ensure the stability of the entire antenna, the printed circuit boards need to be supported by dielectric support columns 60 and fixed by screws 50. Figure 11 and Figure 12 As can be seen, the screw 50 is embedded in the dielectric support column 60. Alternatively, since it is to be embedded into the support column from the front side of the printed circuit board, it is natural to drill screw holes 501 on the front side of the printed circuit board, for example, Figure 13In the example, taking the first printed circuit board 103 and the second printed circuit board 202 as examples, there are four screw holes 501 on the first printed circuit board 103 and eight screw holes 501 on the second printed circuit board 202. Four of the screw holes 501 are used for connection with the first printed circuit board 103, and the remaining four screw holes 501 are used for connection with the third printed circuit board 402. Optionally, the diameter of each of these screw holes 501 can be 3 mm.

[0093] Optionally, in order to reduce the impact on antenna radiation, the support columns and screws in the antenna are made of non-metal.

[0094] Based on the description of the structure of each part of the antenna in the above embodiment, it should be further explained that, because the first printed circuit board 103 and the second printed circuit board 202 are arranged in air, for the first radiating unit 10 and the second radiating unit, it is equivalent to air coupling, and because after the feeding network 30 feeds the four-way sub-signal into the second radiating unit, it is fed from the feeding component 302 into the gaps between the four groove-structured radiating patches 201, and the four gaps couple the signal into the two annular radiating plates in the first radiating unit 10. Therefore, in the embodiment of the present application, it is the gaps between two adjacent radiating patches 201 in the four groove-structured radiating patches 201 that feed the signal fed from the four feeding patches 301 on the back side into the two annular radiating plates in the first radiating unit 10, thereby forming a gap coupling with the two annular radiating plates in the first radiating unit 10, thereby transmitting the signal to space or receiving the electromagnetic wave signal in space, thereby achieving the effect of increasing the antenna bandwidth.

[0095] In the second radiating element 20, the signal passing through the gap between two adjacent radiating patches 201 directly enters the two annular radiating patches in the first radiating element 10. The four grooves in the radiating patch 201 provide path constraints for the signal coupled through the gap. Therefore, the size of the gap and the size of the back feed patch 301 also determine the antenna's radiation performance.

[0096] The antenna provided in the embodiment of the present application has a concentric double-ring radiating plate designed on the top substrate (first printed circuit board 103). Since the size of the ring patch working in the TM11 fundamental mode is much smaller than the size of the circle or rectangle, the use of the ring patch as the radiating unit can reduce the size of the antenna. In addition, the double-ring radiating plate corresponds to the high and low frequency bands of navigation respectively, and the low-frequency ring radiating plate adopts a slow wave design. By extending the electrical length, reducing the frequency and increasing the low-frequency radiation bandwidth, the antenna size is further reduced. There is a gap between the two adjacent groove-structured radiating patches 201 designed on the middle substrate (second printed circuit board 202) and located directly above the back feed plate 301, thereby forming a gap coupling with the concentric double-ring radiating plate on the top substrate, increasing the antenna bandwidth. In the feeding network 30, the four feeding components and the feeding plate 301 printed on the back of the middle substrate constitute four L-shaped probes to ensure the circular polarization characteristics of the antenna, and the broadband power division network 401 printed on the back of the bottom substrate matches the antenna array to ensure that the antenna can achieve broadband use. In other words, in order to achieve broadband coverage of GNSS, this application adopts the design concept of slot coupling to expand the bandwidth, and designs a three-layer stacked substrate with an air gap to reduce the effective dielectric constant. At the same time, the four L-shaped feeds can achieve high precision, matching the broadband feeding network, and the phase difference of each port is 90° to achieve circular polarization characteristics. Through the above design, full coverage of the GNSS satellite navigation frequency band is finally achieved. Therefore, the antenna structure provided in the embodiment of the present application can achieve ultra-wideband coverage while taking into account high gain, low elevation gain, non-circularity and good axial ratio characteristics. Moreover, the array is entirely made of printed circuit boards, which is convenient to manufacture and has high consistency compared to conventional microstrip composite materials in the industry.

[0097] Considering that the metal in the various structures of the above-mentioned embodiments may rust due to prolonged exposure to air, thereby affecting the antenna's radiation performance, the circularly polarized antenna provided in the embodiments of the present application further includes a radome and a cylindrical non-metallic sidewall. The bottom of the radome is connected to the top of the cylindrical non-metallic sidewall to form an antenna cavity. The first radiating element 10, the second radiating element 20, the feed network 30, and the broadband power splitter unit 40 involved in the above-mentioned embodiments are all located within this antenna cavity.

[0098] The radome is made of a non-metallic material, such as FR4 composite material. The non-metallic material used for the columnar sidewalls may also be FR4 composite material. This embodiment of the present application does not limit this.

[0099] Optionally, the shape of the radome can be arc-shaped, square, irregular, etc. The radome can be transparent or opaque. The embodiment of the present application does not limit the shape, color, material, or characteristics of the radome, as long as it allows the antenna's radiation signal to pass through without affecting the radiation effect.

[0100] The antenna structure in the embodiment of the present application has antenna pattern indicators obtained through electromagnetic simulation that meet the design requirements, and in actual simulation, the performance indicators are better than the design requirements. For example, the peak gain, low elevation gain, out-of-roundness and axis ratio all have good indicators, such as Figure 14 The gain simulation result diagram shown is Figure 15 The simulation results of the gain at a low elevation angle of 20° are shown, and Figure 16 The axial ratio simulation results shown in the figure show that the antenna gain is greater than 6.4dBi across the entire frequency band, the minimum gain at a low elevation angle of 20° is -3.0dBi, the non-circularity is less than 0.5, the axial ratio is less than 3.9dB within 80°, and the circular polarization characteristics are good.

[0101] In addition, based on the same inventive concept, embodiments of the present application further provide a navigation device. This navigation device includes the circularly polarized antenna provided in any of the aforementioned embodiments. The implementation solution provided by this navigation device is similar to the implementation solution described above for the circularly polarized antenna. Therefore, the specific limitations of the navigation device can be found in the limitations of the circularly polarized antenna described above and will not be further elaborated here.

[0102] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A circularly polarized antenna, characterized in that: The circularly polarized antenna includes a first radiating element, a second radiating element, a feeding network, and a broadband power splitting unit arranged from top to bottom; the broadband power splitting unit is electrically connected to the feeding network, the feeding network is electrically connected to the second radiating element, and the second radiating element is coupled to the first radiating element; The broadband power splitter is used to convert the received radio frequency signal into four sub-signals that meet the circular polarization requirements; the feeding network is used to feed the four sub-signals into the second radiating unit, so that the second radiating unit is coupled with the first radiating unit for feeding; The first radiating unit includes a low-frequency annular radiator and a high-frequency annular radiator, the low-frequency annular radiator and the high-frequency annular radiator are concentric annular, and the low-frequency annular radiator is a slow-wave structure, and the bandwidth corresponding to the frequency generated by the low-frequency annular radiator and the high-frequency annular radiator during coupling feeding is greater than or equal to the full-band navigation bandwidth; The slow-wave structure is in the shape of a broken line, and the spacing between adjacent inflection points on the broken line is 1 mm; The second radiation unit includes four radiation patches with groove structures, which are symmetrically laid on the upper surface of the second printed circuit board, and a gap of a preset size is spaced between two adjacent radiation patches.

2. The circularly polarized antenna according to claim 1, wherein The inner diameter of the low-frequency annular radiation plate is 50 mm, and the outer diameter of the low-frequency annular radiation plate is 56.8 mm; the inner diameter of the high-frequency annular radiation plate is 34 mm, and the outer diameter of the high-frequency annular radiation plate is 42 mm.

3. The circularly polarized antenna according to claim 1 or 2, characterized in that: The low-frequency annular radiation sheet and the high-frequency annular radiation sheet are laid on the upper surface of the first printed circuit board.

4. The circularly polarized antenna according to claim 1, wherein: The radiation patch with the groove structure is a W-shaped radiation patch or a U-shaped radiation patch.

5. The circularly polarized antenna according to claim 1, wherein: The preset size is 8.73 mm.

6. The circularly polarized antenna according to claim 3, wherein: The diameter of the first printed circuit board is 84 mm, the diameter of the second printed circuit board is 120 mm, and the height between the first printed circuit board and the second printed circuit board is 7 mm.

7. The circularly polarized antenna according to claim 1, wherein: The feeding network includes four feeding plates; the four feeding plates are laid on the lower surface of the second printed circuit board and are correspondingly located directly below the gaps between the radiation patches.

8. The circularly polarized antenna according to claim 7, wherein: The length of the feeding plate is 13 mm and the width is 3 mm.

9. The circularly polarized antenna according to claim 7, wherein: The feed network further comprises four feed components, each of the feed sheets comprising a feed point extending from the upper surface to the lower surface of the second printed circuit board; The upper end of each feeding component passes through a feeding point and reaches the upper surface of the second printed circuit board, and the lower end of each feeding component is connected to the broadband power splitter unit.

10. The circularly polarized antenna according to claim 9, wherein: The feeding component is a feeding needle, and the length of the feeding needle is 13 mm.

11. The circularly polarized antenna according to claim 9, wherein: The broadband power division unit includes a broadband power division network and a third printed circuit board. The broadband power division network is laid on the lower surface of the third printed circuit board, and the lower ends of the four feeding components pass through the third printed circuit board and are connected to the broadband power division network.

12. The circularly polarized antenna according to claim 11, wherein: The diameter of the third printed circuit board is 150 mm, and the height between the third printed circuit board and the second printed circuit board is 13 mm.

13. A navigation device, characterized in that: The navigation device includes the circularly polarized antenna according to any one of claims 1 to 12.

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