Beidou navigation antenna

Abstract

The application provides a Beidou navigation antenna, and relates to the technical field of antennas, and comprises an antenna plate, a first metal plate and a second metal plate.The antenna plate comprises a first dielectric substrate, a first radiator and a second radiator formed on two side surfaces of the first dielectric substrate respectively, and the first radiator and the second radiator constitute a dipole radiator; the first metal plate comprises a second dielectric substrate and a first metal patch formed on one side surface of the second dielectric substrate, and the first metal patch is provided with a first through hole which is consistent with the shape and size of the dipole radiator; and the second metal plate comprises a third dielectric substrate and a second metal patch formed on one side surface of the third dielectric substrate, and the second metal patch is provided with a second through hole which is consistent with the shape and size of the dipole radiator.The technical scheme provided by the application can greatly expand the working bandwidth of the antenna by loading the first metal patch and the second metal patch which are consistent with the shape and size of the dipole radiator on both sides of the dipole radiator.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a Beidou navigation antenna. Background Technology

[0002] The BeiDou system is the world's first satellite navigation system to provide tri-frequency signal services. BeiDou-2 provides three publicly available service signals (B1I, B2I, and B3I) across the B1, B2, and B3 frequency bands. The center frequency of the B1 band is 1561.098 MHz, the B2 band is 1207.14 MHz, and the B3 band is 1268.52 MHz. BeiDou-3 provides five publicly available service signals (B1I, B1C, B2a, B2b, and B3I) across the same three frequency bands. The center frequency of the B1 band is 1575.42 MHz, the B2 band is 1176.45 MHz, and the B3 band is 1268.52 MHz.

[0003] To utilize all the services of the BeiDou system, circularly polarized antennas operating in the aforementioned frequency bands are the preferred design choice for BeiDou navigation antennas. For mobile terminal devices, since the antenna is embedded within the device, the antenna structure needs to be both miniaturized and low-cost. However, in related technologies, BeiDou navigation antennas suffer from drawbacks such as insufficient operating bandwidth, high cost, and complex manufacturing processes. Summary of the Invention

[0004] This invention was completed in order to at least partially solve the technical problems of insufficient operating bandwidth, high cost, and complex manufacturing of BeiDou navigation antennas in the prior art.

[0005] This invention provides a BeiDou navigation antenna, comprising:

[0006] The antenna plate includes a first dielectric substrate, a first radiator formed on one side surface of the first dielectric substrate, and a second radiator formed on the opposite side surface of the first dielectric substrate, wherein the first radiator and the second radiator constitute a dipole radiator.

[0007] A first metal plate includes a second dielectric substrate and a first metal patch formed on one side surface of the second dielectric substrate, wherein the one side surface of the second dielectric substrate and the one side surface of the first dielectric substrate are disposed face-to-face, and the first metal patch has a first through-hole with a shape and size consistent with that of the dipole radiator; and,

[0008] The second metal plate includes a third dielectric substrate and a second metal patch formed on one side surface of the third dielectric substrate, wherein the one side surface of the third dielectric substrate is disposed face-to-face with the other side surface of the first dielectric substrate, and a second through hole is formed on the second metal patch having a shape and size consistent with the dipole radiator.

[0009] The first metal plate and the antenna plate, and the antenna plate and the second metal plate are all spaced apart; the first metal patch, the first radiator, the second radiator and the second metal patch are electrically connected.

[0010] Optionally, the antenna board further includes: a microstrip phase shifter formed on the first dielectric substrate; the microstrip phase shifter is connected to the first radiator and the second radiator respectively, for performing 90° phase shift feeding, so that the first radiator and the second radiator are 90° out of phase.

[0011] Optionally, the microstrip phase shifter includes: a first phase shifter formed on one side surface of the first dielectric substrate, and a second phase shifter formed on the other side surface of the first dielectric substrate; the first radiator includes a first radiating portion and a second radiating portion; the second radiator includes a third radiating portion and a fourth radiating portion; wherein the first radiating portion is connected to the second radiating portion through the first phase shifter, and the third radiating portion is connected to the fourth radiating portion through the second phase shifter.

[0012] Optionally, the BeiDou navigation antenna further includes: a coaxial feed line; the coaxial feed line includes an inner conductor and an outer conductor; the first phase shifter and the first radiator are connected to the inner conductor of the coaxial feed line, and the second phase shifter and the second radiator are connected to the outer conductor of the coaxial feed line.

[0013] Optionally, both the first radiating part and the second radiating part are elongated structures, with one end of each part close to the other and set at 90°. The first phase shifter is a three-quarter ring structure. One end of the first radiating part is connected to one end of the first phase shifter, and the other end of the first phase shifter is connected to one end of the second radiating part.

[0014] Both the third and fourth radiating parts are elongated structures, with one end of each part close together and set at a 90° angle. The second phase shifter is a three-quarters circular ring structure. One end of the third radiating part is connected to one end of the second phase shifter, and the other end of the second phase shifter is connected to one end of the fourth radiating part.

[0015] The first radiating part, the second radiating part, the third radiating part and the fourth radiating part are arranged in a cross shape.

[0016] Optionally, the first radiator further includes a first bend and a second bend, the first bend being connected to an end of the first radiator and the second bend being connected to an end of the second radiator; the second radiator further includes a third bend and a fourth bend, the third bend being connected to an end of the third radiator and the fourth bend being connected to an end of the fourth radiator.

[0017] Optionally, the distance between the antenna plate and the first metal plate is in the range of 5 to 10 mm; the antenna plate further includes: a first helical stub and a second helical stub formed on one side surface of the first dielectric substrate, and a third helical stub and a fourth helical stub formed on the other side surface of the first dielectric substrate; wherein the first helical stub is connected to the middle of the first radiating portion, the second helical stub is connected to the middle of the second radiating portion, the third helical stub is connected to the middle of the third radiating portion, and the fourth helical stub is connected to the middle of the fourth radiating portion.

[0018] Optionally, the first to fourth spiral branches are all inward spiral structures; the inward spiral structure includes a first spiral arm to an Nth spiral arm that are connected end to end and decrease in length, where N is 3, 4 or 5.

[0019] Optionally, the Beidou navigation antenna further includes: four metal pillars; one end of each of the four metal pillars is connected to the first metal patch, and the other end of each of the four metal pillars is connected to the tail end of the first spiral arm and the head end of the second spiral arm of the four spiral branches, respectively.

[0020] Optionally, the distance between the antenna plate and the second metal plate is one-quarter wavelength, and the frequency corresponding to the wavelength is the center frequency of the operating frequency band of the Beidou navigation antenna.

[0021] The technical solution provided by this invention may include the following beneficial effects:

[0022] The BeiDou navigation antenna provided by this invention, by loading a first metal patch and a second metal patch with the same aperture shape and size as the dipole radiator on both sides of the dipole radiator, can greatly widen the antenna's operating bandwidth and cover as much of the BeiDou system's operating frequency band as possible to receive all signals from BeiDou satellites. Furthermore, the BeiDou navigation antenna adopts a microstrip structure, which correspondingly reduces the antenna size and lowers the antenna manufacturing cost.

[0023] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0024] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0025] Figure 1 A three-dimensional structural schematic diagram of the Beidou navigation antenna provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the antenna board provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the first radiator and the first phase shifter provided in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the structure of the second radiator and the second phase shifter provided in an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the structure of the first metal plate provided in an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the structure of the second metal plate provided in an embodiment of the present invention;

[0031] Figure 7 The simulation results of the return loss of the Beidou navigation antenna provided in the embodiment of the present invention are shown in the figure.

[0032] Figure 8 The figure shows the simulation results of the axial ratio of the Beidou navigation antenna provided in the embodiment of the present invention.

[0033] In the figure: 1 - Antenna plate; 11 - First dielectric substrate; 12 - Dipole radiator; 121 - First radiator; 1211 - First radiating section; 1212 - Second radiating section; 1213 - First bending section; 1214 - Second bending section; 122 - Second radiator; 1221 - Third radiating section; 1222 - Fourth radiating section; 1223 - Third bending section; 1224 - Fourth bending section; 13 - Microstrip phase shifter; 131 - First phase shifter; 132 - Second phase shifter; 141 - First helical stub; 142 - Second helical stub; 143 - Third helical stub; 144 - Fourth helical stub; 2 - First metal plate; 21 - Second dielectric substrate; 22 - First metal patch; 3 - Second metal plate; 31 - Third dielectric substrate; 32 - Second metal patch; 4 - Metal pillar; 5 - Coaxial feed line; 6 - Support pillar. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the present invention. In other instances, well-known circuits, materials, or methods have not been specifically described to avoid obscuring the present invention.

[0035] It should be noted that the orientation or positional relationship indicated by various orientation terms is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the purpose of facilitating the description of the present invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0036] Furthermore, the terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence; and, where there is no conflict, the embodiments and features in the embodiments of this invention can be arbitrarily combined with each other. Those skilled in the art should understand that the illustrations provided herein are for illustrative purposes only, and the illustrations are not necessarily drawn to scale. The lines in the figures are divided into solid lines and dashed lines, where solid lines indicate that the identified object is on the front side of the current substrate, and dashed lines indicate that the identified object is on the back side of the current substrate. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be a direct connection or coupling to the other element, or there may be intermediate elements.

[0037] This invention provides a broadband circularly polarized BeiDou navigation antenna. For example... Figure 1As shown, the Beidou navigation antenna includes: antenna plate 1, first metal plate 2, and second metal plate 3.

[0038] like Figure 1 and Figure 2 As shown, the antenna plate 1 includes a first dielectric substrate 11, a first radiator 121 formed on one side surface of the first dielectric substrate 11, and a second radiator 122 formed on the opposite side surface of the first dielectric substrate 11. The first radiator 121 and the second radiator 122 constitute a dipole radiator 12.

[0039] Specifically, in Figure 1 In the middle, the first radiator 121 is located on the upper surface of the first dielectric substrate 11 (i.e., Figure 2 The first radiator 121 on the front side of the substrate shown refers to Figure 2 The second radiator 122 is located on the lower surface of the first dielectric substrate 11 (i.e., a relatively dark structure). Figure 2 On the back side of the substrate shown, the second radiator 122 refers to Figure 2 (The structure is relatively light-colored in the middle). The first radiator 121 and the second radiator 122 are arranged in a centrally symmetrical manner, and the two constitute a dipole radiator 12, with the first radiator 121 serving as one arm of the dipole radiator 12 and the second radiator 122 serving as the other arm of the dipole radiator 12.

[0040] The first radiator 121 and the second radiator 122 can be formed on the first dielectric substrate 11 by etching or electroplating. The first dielectric substrate 11 can be an FR4 substrate with a thickness of 1 mm.

[0041] like Figure 1 and Figure 5 As shown, the first metal plate 2 includes a second dielectric substrate 21 and a first metal patch 22 formed on one side surface of the second dielectric substrate 21. The one side surface of the second dielectric substrate 21 is disposed face-to-face with the one side surface of the first dielectric substrate 11. A first through hole 221 with the same shape and size as the dipole radiator 12 is formed on the first metal patch 22, so that the shape of the first metal patch 22 is complementary to that of the dipole radiator 12.

[0042] Specifically, in Figure 1 In the middle, the first metal patch 22 is located on the lower surface of the second dielectric substrate 21 (i.e., Figure 5 (shown as the back side of the substrate), and the lower surface of the second dielectric substrate 21 is disposed face-to-face with the upper surface of the first dielectric substrate 11.

[0043] The first metal patch 22 can be formed on the second dielectric substrate 21 by etching or electroplating. The second dielectric substrate 21 can be an FR4 substrate with a thickness of 1 mm.

[0044] like Figure 1 and Figure 6 As shown, the second metal plate 3 includes a third dielectric substrate 31 and a second metal patch 32 formed on one side surface of the third dielectric substrate 31. The one side surface of the third dielectric substrate 31 is disposed face-to-face with the other side surface of the first dielectric substrate 11. A second through-hole 321 with the same shape and size as the dipole radiator 12 is formed on the second metal patch 32, making the shapes of the second metal patch 32 complementary to those of the dipole radiator 12. In fact, the opening shape of the first metal patch 22 is the same as the opening shape and size of the second metal patch 32.

[0045] Specifically, in Figure 1 In the middle, the second metal patch 32 is located on the upper surface of the third dielectric substrate 31 (i.e., Figure 6 (as shown on the front side of the substrate), and the upper surface of the third dielectric substrate 31 is disposed face-to-face with the lower surface of the first dielectric substrate 11.

[0046] The second metal patch 32 can be formed on the third dielectric substrate 31 by etching or electroplating. The third dielectric substrate 31 can be an FR4 substrate with a thickness of 1 mm.

[0047] In this design, the first metal plate 2 and the antenna plate 1, as well as the antenna plate 1 and the second metal plate 3, are spaced apart. In other words, the first metal plate 2 and the antenna plate 1 are spaced apart by a certain distance, and the antenna plate 1 and the second metal plate 3 are also spaced apart by a certain distance, with the antenna plate 1 located between the first metal plate 2 and the second metal plate 3. The first metal patch 22, the first radiator 121, the second radiator 122, and the second metal patch 32 are electrically connected. This invention does not limit the specific implementation of the electrical connection; it only requires the formation of a conductive circuit.

[0048] In this embodiment, a first metal patch with the same opening shape and size as the dipole radiator is loaded above the dipole radiator. The two are connected to each other to achieve power feeding and excitation, which can introduce an additional resonant point and broaden the working bandwidth of the antenna. A second metal patch with the same opening shape and size as the dipole radiator is loaded below the dipole radiator. This can achieve directional radiation of the antenna, improve the front-to-back radiation ratio of the antenna, and slightly broaden the working bandwidth.

[0049] In one specific embodiment, the Beidou navigation antenna further includes a plurality of support columns 6. The plurality of support columns 6 are used to support the three dielectric substrates: the first dielectric substrate 11, the second dielectric substrate 21, and the third dielectric substrate 31. Therefore, each support column 6 needs to pass through the first dielectric substrate 11, with one end fixedly connected to the second dielectric substrate 21 and the other end fixedly connected to the third dielectric substrate 31.

[0050] like Figure 1As shown, in this embodiment, four support columns 6 can be used, located at the four corners of the first to third dielectric substrates respectively, and arranged perpendicularly to each dielectric substrate. The support columns 6 can be made of nylon, that is, the support columns 6 are specifically nylon columns.

[0051] In one specific implementation, such as Figure 2 As shown, the antenna plate 1 further includes a microstrip phase shifter 13 formed on the first dielectric substrate 11. The microstrip phase shifter 13 is connected to the first radiator 121 and the second radiator 122 respectively, and is used to perform 90° phase shift feeding, so that the phase difference between the first radiator 121 and the second radiator 122 is 90°.

[0052] Furthermore, such as Figures 2 to 4 As shown, the microstrip phase shifter 13 includes a first phase shifter 131 formed on one side surface of the first dielectric substrate 11, and a second phase shifter 132 formed on the other side surface of the first dielectric substrate 11. The first radiator 121 includes a first radiating portion 1211 and a second radiating portion 1212; the second radiator 122 includes a third radiating portion 1221 and a fourth radiating portion 1222; wherein the first radiating portion 1211 is connected to the second radiating portion 1212 through the first phase shifter 131, and the third radiating portion 1221 is connected to the fourth radiating portion 1222 through the second phase shifter 132.

[0053] Specifically, in Figure 1 In the middle, the first phase shifter 131 is located on the upper surface of the first dielectric substrate 11 (i.e., Figure 2 The second phase shifter 132 is located on the lower surface of the first dielectric substrate 11 (i.e., the front side of the substrate shown). Figure 2 (The back side of the substrate shown). The first phase shifter 131 and the second phase shifter 132 are formed on the upper and lower sides of the first dielectric substrate 11 by etching or electroplating, respectively.

[0054] By connecting (e.g., welding) the first phase shifter 131 and the second phase shifter 132 to the first radiator 121 and the second radiator 122 respectively, a 90° phase shift feeding is achieved, so that the phase difference between the first radiator 121 and the second radiator 122 is 90°, thus realizing right-hand circular polarization radiation.

[0055] In one specific embodiment, the BeiDou navigation antenna further includes a coaxial feed line 5. The coaxial feed line 5 includes an inner conductor and an outer conductor. A first phase shifter 131 and a first radiator 121 located on the upper side of the first dielectric substrate 11 are connected to the inner conductor of the coaxial feed line 5, and a second phase shifter 132 and a second radiator 122 located on the lower side of the first dielectric substrate 11 are connected to the outer conductor of the coaxial feed line 5. The coaxial feed line 5 can be arranged perpendicularly to the antenna plate 1.

[0056] In this embodiment, the coaxial feed line 5 passes through the central region of the first dielectric substrate 11 and is coaxially arranged with the dipole radiator 12.

[0057] In one specific implementation, such as Figure 2 and Figure 3 As shown, both the first radiating part 1211 and the second radiating part 1212 are elongated structures, with one end of each part close to the other and set at a 90° angle. The first phase shifter 131 is a three-quarters circular structure. One end of the first radiating part 1211 is connected to one end of the first phase shifter 131, and the other end of the first phase shifter 131 is connected to one end of the second radiating part 1212.

[0058] Specifically, in Figure 3 In this configuration, the ends of the first radiating part 1211 and the second radiating part 1212 that are close to each other can be called the head end. The head end of the first radiating part 1211 is connected to one end of the first phase shifter 131, and the other end of the first phase shifter 131 is connected to the head end of the second radiating part 1212.

[0059] like Figure 2 and Figure 4 As shown, the third radiating part 1221 and the fourth radiating part 1222 are both elongated structures, with one end of each part close to the other and set at 90°. The second phase shifter 132 is a three-quarters annular structure. One end of the third radiating part 132 is connected to one end of the second phase shifter 1221, and the other end of the second phase shifter 132 is connected to one end of the fourth radiating part 1222.

[0060] exist Figure 4 In this configuration, the end of the third radiating section 1221 and the fourth radiating section 1222 that is close to each other can be called the head end. The head end of the third radiating section 1221 is connected to one end of the second phase shifter 132, and the other end of the second phase shifter 132 is connected to the head end of the fourth radiating section 1222.

[0061] like Figures 2 to 4 As shown, the first radiating part 1211, the second radiating part 1212, the third radiating part 1221 and the fourth radiating part 1222 are arranged in a cross shape.

[0062] In this embodiment, since the first radiating part 1211, the second radiating part 1212, the third radiating part 1221, and the fourth radiating part 1222 are all elongated structures, when they are arranged in a cross shape, they form two horizontal and vertical arms of the cross. Furthermore, the first radiating part 1211 and the third radiating part 1221 constitute a... Figure 2 The cross-shaped horizontal arm shown, the second radiating part 1212 and the fourth radiating part 1222 constitute a cross. Figure 2 The vertical arms are shown in a cross shape. It can be seen that the dipole radiator formed by the first to fourth radiating parts can be called a cross dipole radiator.

[0063] In a specific embodiment, as Figures 2 to 4 shown, the first radiator 121 further includes a first bending portion 1213 and a second bending portion 1214. The first bending portion 1213 is connected to the end of the first radiating portion 1211, and the second bending portion 1214 is connected to the end of the second radiating portion 1212. The second radiator 122 further includes a third bending portion 1223 and a fourth bending portion 1224. The third bending portion 1223 is connected to the end of the third radiating portion 1221, and the fourth bending portion 1224 is connected to the end of the fourth radiating portion 1222.

[0064] In Figure 3 it, the tail end of the first radiating portion 1211 is connected to the first bending portion 1213, and the tail end of the second radiating portion 1212 is connected to the second bending portion 1214. In Figure 4 it, the tail end of the third radiating portion 1221 is connected to the third bending portion 1223, and the tail end of the fourth radiating portion 1222 is connected to the fourth bending portion 1224.

[0065] In this embodiment, the first bending portion 1213, the second bending portion 1214, the third bending portion 1223, and the fourth bending portion 1224 are all strip-shaped structures. They are respectively perpendicularly connected to the tail ends of the first radiating portion 1211, the second radiating portion 1212, the third radiating portion 1221, and the fourth radiating portion 1222, and the bending directions are the same, so that the entire dipole radiator 12 is formed into a "卍" shape, or a symmetric figure of a "卍" shape. Among them, the second bending portion 1214, the second radiating portion 1212, the fourth radiating portion 1222, and the fourth bending portion 1224 form a Z shape, and the first bending portion 1213, the first radiating portion 1211, the third radiating portion 1221, and the third bending portion 1223 form another Z shape, thus forming a cross-Z-shaped dipole radiator.

[0066] In this embodiment, the bent portions at the ends of the first radiator 121 and the second radiator 122 are equivalent to capacitive loading, which reduces the overall size of the antenna compared with the traditional rectangular dipole radiator.

[0067] In a specific embodiment, the Beidou navigation antenna further includes: a plurality of metal posts 4. The dipole radiator 12 is connected to the first metal patch 22 through a plurality of metal posts 4 (such as welding) to achieve feeding excitation.

[0068] In this embodiment, since the shape and size of the opening (also called the slot) on the first metal patch 22 are the same as those of the dipole radiator 12, the shape of the first through hole 221 is also a swastika shape, or a symmetrical swastika shape. The current entering the dipole radiator 12 flows through several metal pillars 4 to the first metal patch 22, generating electromagnetic radiation around the swastika-shaped slot of the first metal patch 22, creating additional resonant points and widening the antenna's operating bandwidth. Moreover, the first metal patch 22 uses a swastika-shaped slot with the same shape and size as the dipole radiator 12, which ensures that the generated resonant point is within the required operating frequency band of the antenna, while not affecting the radiation pattern, allowing the antenna to maintain right-hand circular polarization radiation.

[0069] In one specific embodiment, the distance between the antenna plate 1 and the first metal plate 2 is in the range of 5 to 10 mm.

[0070] In this embodiment, because the distance between the antenna plate 1 and the first metal plate 2 is very close, electromagnetic coupling occurs between the dipole radiator 12 and the first metal patch 22, generating unwanted operating frequencies and causing interference signals to be radiated and received. To solve this problem, a decoupling component can be loaded on the arm of the dipole radiator 12.

[0071] Accordingly, the antenna plate 1 further includes: a first helical stub 141 and a second helical stub 142 formed on one side surface of the first dielectric substrate 11, and a third helical stub 143 and a fourth helical stub 144 formed on the other side surface of the first dielectric substrate 11. The first helical stub 141 is connected to the middle portion of the first radiating portion 1211, the second helical stub 142 is connected to the middle portion of the second radiating portion 1212, the third helical stub 143 is connected to the middle portion of the third radiating portion 1221, and the fourth helical stub 144 is connected to the middle portion of the fourth radiating portion 1222.

[0072] Specifically, in Figure 1 In the middle, the first helical stub 141 and the second helical stub 142 are located on the upper surface of the first dielectric substrate 11 (i.e., Figure 2 The third helical stub 143 and the fourth helical stub 144 are located on the lower surface of the first dielectric substrate 11 (i.e., the front side of the substrate shown). Figure 2(The back side of the substrate shown). The end where the first helical branch 141 is connected to the first radiating portion 1211 can be called the head end, and the tail end of the first helical branch 141 is the free end. The connection between the first helical branch 141 and the first radiating portion 1211 in the middle means that the first helical branch 141 and the first radiating portion 1211 are connected in the middle region. As for the "middle region", it refers to the region that is different from the head end and the tail end. Those skilled in the art can define the size of the middle region according to actual needs. Similarly, the end connecting the second spiral branch 142 / third spiral branch 143 / fourth spiral branch 144 to the second radiating part 1212 / third radiating part 1221 / fourth radiating part 1222 can be called the head end, and the tail end of the second spiral branch 142 / third spiral branch 143 / fourth spiral branch 144 is the free end. The middle connection of the second spiral branch 142 / third spiral branch 143 / fourth spiral branch 144 to the second radiating part 1212 / third radiating part 1221 / fourth radiating part 1222 refers to the connection of the middle region of the second spiral branch 142 / third spiral branch 143 / fourth spiral branch 144 to the second radiating part 1212 / third radiating part 1221 / fourth radiating part 1222.

[0073] like Figures 2 to 4 As shown, the first bend 1213 and the first spiral stub 141 are located on both sides of the first radial portion 1211, the second bend 1214 and the second spiral stub 142 are located on both sides of the second radial portion 1212, the third bend 1223 and the third spiral stub 143 are located on both sides of the third radial portion 1221, and the fourth bend 1224 and the fourth spiral stub 144 are located on both sides of the fourth radial portion 1222. In other words, the bending direction from the first bend to the fourth bend (e.g., ...) Figure 2 (as shown counterclockwise) and the bending direction from the first spiral branch to the fourth spiral branch (as shown) Figure 2 (The clockwise direction shown is the opposite.)

[0074] In this embodiment, by loading several helical stubs on the arm of the dipole radiator 12 as decoupling components, the coupling between the dipole radiator and the first metal patch 22 is reduced. Adjusting the size and number of helical turns of each helical stub can increase the return loss outside the working bandwidth, thereby filtering out noise.

[0075] In one specific implementation, such as Figures 2 to 4 As shown, the first to fourth spiral branches are all inward spiral structures. Each inward spiral structure consists of a first spiral arm to an Nth spiral arm, connected end-to-end with decreasing lengths, where N is 3, 4, or 5. Each spiral arm is a rectangular strip structure. The first spiral arm can be perpendicular to each radial section, and adjacent spiral arms can be perpendicular to each other.

[0076] In this embodiment, considering that increasing the number of spiral turns would complicate antenna fabrication and that the clutter suppression effect would not be significant, each spiral stub is selected to include four spiral arms. Specifically, the first spiral arm's head is connected to the middle of each radiating section, the first spiral arm's tail is connected to the head of the second spiral arm, the second spiral arm's tail is connected to the head of the third spiral arm, the third spiral arm's tail is connected to the head of the fourth spiral arm, and the fourth spiral arm's tail is a free end.

[0077] In one specific implementation, such as Figures 1 to 4 As shown, four metal pillars are used to connect the dipole radiator 12 and the first metal patch 22, and they are arranged perpendicularly to the antenna plate 1 and the first metal plate 2. One end of each of the four metal pillars 4 is connected to the first metal patch 22, and the other end of each of the four metal pillars 4 is connected to the tail end of the first spiral arm and the head end of the second spiral arm of the four spiral stubs 141 to 144, respectively, thereby realizing the connection between the first metal patch 22 and the dipole radiator 12 through the four metal pillars and the four spiral stubs.

[0078] Specifically, the other end of the first metal pillar 4 is connected to the tail end of the first spiral arm and the head end of the second spiral arm of the first spiral branch 141; the other end of the second metal pillar 4 is connected to the tail end of the first spiral arm and the head end of the second spiral arm of the second spiral branch 142; the other end of the third metal pillar 4 is connected to the tail end of the first spiral arm and the head end of the second spiral arm of the third spiral branch 143; and the other end of the fourth metal pillar 4 is connected to the tail end of the first spiral arm and the head end of the second spiral arm of the fourth spiral branch 144.

[0079] In this embodiment, the position of the four metal pillars affects the radiation effect of the first metal patch 22. According to antenna design theory, the operating frequency of the antenna is different depending on the position of the feed point, i.e., the four metal pillars 4. By forming each metal pillar 4 at the first bend of each helical branch (i.e., the tail end of the first helical arm and the head end of the second helical arm), the operating frequency of the first metal patch 22 is in the operating frequency band required by the Beidou navigation antenna, thereby achieving the purpose of widening the operating bandwidth of the designed antenna.

[0080] In one specific embodiment, the distance between the antenna plate 1 and the second metal plate 3 is one-quarter wavelength, and the frequency corresponding to the wavelength is the center frequency of the operating frequency band of the Beidou navigation antenna.

[0081] In this embodiment, in order to achieve directional radiation of the antenna, a second metal plate 3 is loaded at a quarter-wavelength spacing below the antenna plate 1. The frequency corresponding to this wavelength is the center frequency of the antenna's operating frequency band, i.e., 1376MHz.

[0082] Since the shape and size of the opening (also called the slot) on the second metal patch 32 are the same as those of the dipole radiator 12, the shape of the second through-hole 321 is also a swastika shape, or a symmetrical swastika shape. Therefore, the second metal patch 32 and the first metal patch 22 have the same structure. After the electromagnetic radiation generated by the dipole radiator 12 and the first metal patch 22 reaches the second metal patch 32, it excites a rotating current around the swastika-shaped slot on the second metal patch 32. The rotation direction of the current is the same as that of the dipole radiator 12 and the first metal patch 22, which improves the radiation ratio of the antenna and slightly widens the operating bandwidth of the antenna.

[0083] like Figure 7 As shown, the Beidou navigation antenna is in S 11 The simulated bandwidth at <-10dB is 980-1640MHz. For example... Figure 8 As shown, the simulated bandwidth of the Beidou navigation antenna when AR < 3dB is 1070-1630MHz, which realizes wideband circular polarization radiation. It can meet the bandwidth requirements of the three frequency bands B1, B2 and B3 of the Beidou navigation system, and covers the entire working frequency band of the Beidou system. Therefore, it can receive all signals from Beidou satellites.

[0084] The Beidou navigation antenna provided in this invention reduces the overall size of the antenna by replacing the traditional rectangular dipole radiator with a cross-shaped Z-shaped dipole radiator. By loading a first metal patch with a complementary shape above the dipole radiator and connecting them with four metal pillars, power excitation is achieved, introducing an additional resonant point and widening the operating bandwidth. Rectangular spiral stubs are loaded onto each radiating part of the dipole radiator as decoupling components, and the size of each spiral stub is adjusted to drastically reduce the antenna's radiation and reception efficiency outside the operating bandwidth, reducing the radiation and reception of interference signals. By improving the second metal patch to have the same structure as the first metal patch, with both having the same slot shape and size as the dipole radiator, the antenna's radiation ratio is improved, and the operating bandwidth is slightly widened. Furthermore, the antenna uses a microstrip structure, reducing its size and manufacturing costs.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Beidou navigation antenna, characterized in that, include: The antenna plate includes a first dielectric substrate, a first radiator formed on one side surface of the first dielectric substrate, and a second radiator formed on the opposite side surface of the first dielectric substrate, wherein the first radiator and the second radiator constitute a dipole radiator. The first metal plate includes a second dielectric substrate and a first metal patch formed on one side surface of the second dielectric substrate, wherein the one side surface of the second dielectric substrate and the one side surface of the first dielectric substrate are disposed face to face, and a first through hole is formed on the first metal patch that is consistent with the shape and size of the dipole radiator. as well as, The second metal plate includes a third dielectric substrate and a second metal patch formed on one side surface of the third dielectric substrate, wherein the one side surface of the third dielectric substrate is disposed face-to-face with the other side surface of the first dielectric substrate, and a second through hole is formed on the second metal patch having a shape and size consistent with the dipole radiator. The first metal plate and the antenna plate, and the antenna plate and the second metal plate are all spaced apart; the first metal patch, the first radiator, the second radiator and the second metal patch are electrically connected.

2. The Beidou navigation antenna according to claim 1, characterized in that, The antenna board further includes: a microstrip phase shifter formed on the first dielectric substrate; the microstrip phase shifter is connected to the first radiator and the second radiator respectively, and is used to perform 90° phase shift feeding, so that the first radiator and the second radiator are 90° out of phase.

3. The Beidou navigation antenna according to claim 2, characterized in that, The microstrip phase shifter includes: a first phase shifter formed on one side surface of the first dielectric substrate, and a second phase shifter formed on the other side surface of the first dielectric substrate; the first radiator includes a first radiating portion and a second radiating portion; the second radiator includes a third radiating portion and a fourth radiating portion; wherein the first radiating portion is connected to the second radiating portion through the first phase shifter, and the third radiating portion is connected to the fourth radiating portion through the second phase shifter.

4. The Beidou navigation antenna according to claim 3, characterized in that, Also includes: Coaxial feeder cable; The coaxial feeder includes an inner conductor and an outer conductor; the first phase shifter and the first radiator are connected to the inner conductor of the coaxial feeder, and the second phase shifter and the second radiator are connected to the outer conductor of the coaxial feeder.

5. The Beidou navigation antenna according to claim 3, characterized in that, Both the first radiating part and the second radiating part are elongated structures, with one end of each part close together and set at 90°. The first phase shifter is a three-quarter ring structure. One end of the first radiating part is connected to one end of the first phase shifter, and the other end of the first phase shifter is connected to one end of the second radiating part. Both the third and fourth radiating parts are elongated structures, with one end of each part close together and set at a 90° angle. The second phase shifter is a three-quarters circular ring structure. One end of the third radiating part is connected to one end of the second phase shifter, and the other end of the second phase shifter is connected to one end of the fourth radiating part. The first radiating part, the second radiating part, the third radiating part and the fourth radiating part are arranged in a cross shape.

6. The Beidou navigation antenna according to claim 3 or 5, characterized in that, The first radiator further includes a first bent portion and a second bent portion, wherein the first bent portion is connected to the end of the first radiator and the second bent portion is connected to the end of the second radiator; the second radiator further includes a third bent portion and a fourth bent portion, wherein the third bent portion is connected to the end of the third radiator and the fourth bent portion is connected to the end of the fourth radiator.

7. The Beidou navigation antenna according to claim 3 or 5, characterized in that, The distance between the antenna plate and the first metal plate is in the range of 5 to 10 mm; the antenna plate further includes: a first helical stub and a second helical stub formed on one side surface of the first dielectric substrate, and a third helical stub and a fourth helical stub formed on the other side surface of the first dielectric substrate; wherein the first helical stub is connected to the middle of the first radiating portion, the second helical stub is connected to the middle of the second radiating portion, the third helical stub is connected to the middle of the third radiating portion, and the fourth helical stub is connected to the middle of the fourth radiating portion.

8. The Beidou navigation antenna according to claim 7, characterized in that, The first to fourth spiral branches are all inward spiral structures; the inward spiral structure includes a first spiral arm to an Nth spiral arm that are connected end to end and decrease in length, where N is 3, 4 or 5.

9. The Beidou navigation antenna according to claim 8, characterized in that, Also includes: Four metal pillars; one end of each of the four metal pillars is connected to the first metal patch, and the other end of each of the four metal pillars is connected to the tail end of the first spiral arm and the head end of the second spiral arm of the four spiral branches, respectively.

10. The Beidou navigation antenna according to claim 1, characterized in that, The distance between the antenna plate and the second metal plate is one-quarter wavelength, and the frequency corresponding to the wavelength is the center frequency of the operating frequency band of the Beidou navigation antenna.

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