Dual-frequency navigation antenna and satellite communication system

Abstract

The invention discloses a double-frequency navigation antenna and a satellite communication system, and relates to the technical field of antennae, the antenna comprises a dielectric substrate and a metal radiator on one side of the dielectric substrate; metal floors electrically connected with the metal floor are arranged on two opposite sides of the dielectric substrate along the Z direction; the metal radiator comprises a radiation body and a parasitic resonance structure, one end of the parasitic resonance structure is electrically connected with the radiation body and extends in the Z direction, the other end of the parasitic resonance structure extends in the X direction or the Y direction, then extends in the Z direction and is connected to the dielectric substrate, and parasitic resonance protrusions are arranged on the two opposite sides of the parasitic resonance structure in the X direction or the Y direction. The parasitic resonance protrusions extend in the X direction or the Y direction. The radiation body supports a first resonant mode to work in a first working frequency band, and electromagnetic coupling of the parasitic resonant structure and the radiation body introduces a second resonant mode to work in a second working frequency band higher than the first working frequency band. According to the invention, miniaturization, high radiation efficiency and low-cost batch manufacturing of the double-frequency navigation antenna can be realized.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a dual-frequency navigation antenna and a satellite communication system. Background Technology

[0002] With the widespread application of GNSS (Global Navigation Satellite System) in the commercial field, the demand for miniaturized, low-cost, easy-to-assemble, and high-performance antennas is increasing, posing new challenges to antenna design. GPS (Global Positioning System), as the world's earliest satellite communication system, provides users with all-weather, most-area location and navigation information in its civilian frequency bands. Its main frequency bands include GPS L1 (center frequency 1575 MHz, bandwidth 20 MHz), L2 (center frequency 1227 MHz, bandwidth 20 MHz), and L5 (center frequency 1176 MHz, bandwidth 24 MHz). BDS (BeiDou Navigation Satellite System) is also one of the world's important satellite communication systems, with frequency bands including BeiDou B2a (center frequency 1176 MHz, bandwidth 20 MHz), B2b (center frequency 1207 MHz, bandwidth 20 MHz), and B2c (center frequency 1575 MHz, bandwidth 32.736 MHz).

[0003] To ensure navigation accuracy, antennas need to cover as many frequency bands as possible. Traditional dual-band navigation antennas often employ a double-layer patch antenna structure, where the upper and lower PCBs (Printed Circuit Boards) use different patch designs to achieve dual-band radiation, offering advantages such as low profile and miniaturization. However, the traditional dielectric substrate with a thickness of approximately 1 mm significantly reduces the radiation efficiency of patch antennas. Therefore, these antennas typically require specially customized, thicker dielectric substrates, hindering large-scale production applications. Furthermore, the double-layer structure is relatively complex to assemble and difficult to integrate into overall system designs. Ceramic antennas are another commonly used solution, but they are heavier, and achieving dual-band operation usually requires a stacked structure, increasing both cost and overall weight, thus limiting their application in many scenarios. Summary of the Invention

[0004] The main objective of this invention is to propose a dual-frequency navigation antenna and satellite communication system, aiming to achieve miniaturization, high radiation efficiency, and low-cost mass production of the dual-frequency navigation antenna.

[0005] To achieve the above objectives, the present invention proposes a dual-frequency navigation antenna, comprising: A dielectric substrate, wherein metal ground planes are respectively provided on two opposite sides along the Z direction; A metal radiator is disposed on one side of the dielectric substrate and electrically connected to the metal ground plane. The metal radiator includes a radiating body and a parasitic resonant structure. One end of the parasitic resonant structure is electrically connected to the radiating body and extends along the Z direction. The other end of the parasitic resonant structure extends along the X or Y direction and then extends along the Z direction and is connected to the dielectric substrate. Parasitic resonant protrusions are provided on opposite sides of the parasitic resonant structure along the X or Y direction. The parasitic resonant protrusions extend along the X or Y direction. The radiating body is configured to support a first resonant mode to operate in a first operating frequency band, and the parasitic resonant structure introduces a second resonant mode to operate in a second operating frequency band through electromagnetic coupling with the radiating body, the second operating frequency band being higher than the first operating frequency band.

[0006] In one embodiment, the metal radiator is welded to the dielectric substrate.

[0007] In one embodiment, the radiating body has a connecting node and four radiating arms. The connecting node is electrically connected to the parasitic resonant structure. The radiating arms are connected to each other through the connecting node. The radiating arms are radially distributed, and the included angle between two adjacent radiating arms is 90 degrees.

[0008] In one embodiment, each of the radiating arms has a first profile segment and a second profile segment at the end away from the connecting node. The first contour segment extends along the X direction; The second contour segment extends along the Y direction; The first contour segment and the second contour segment are each provided with a support member, which extends along the Z direction and is connected to the dielectric substrate.

[0009] In one embodiment, each of the radiating arms is provided with a first metal branch and a second metal branch; The first metal stub of one of two adjacent radiating arms is electrically connected to the second metal stub of the other radiating arm; One end of the first metal branch extends along the X direction to form a first radiation groove with the corresponding radiation arm, and the other end of the first metal branch extends along the Z direction and is connected to the dielectric substrate. One end of the second metal branch extends along the Y direction to form a second radiation groove between itself and the corresponding radiation arm, and the other end of the second metal branch extends along the Z direction and is connected to the dielectric substrate.

[0010] In one embodiment, each of two adjacent radiating arms in the four radiating arms is provided with a feed slot, and the included angle between the two feed slots is 90 degrees. The metal radiator further includes two power feeding sections, one end of each power feeding section is connected to the connection node, and the other end extends along the Z direction and is fixed to the side of the dielectric substrate away from the metal radiator, and is electrically connected to the metal ground.

[0011] In one embodiment, the dielectric substrate is a rectangular substrate; the metal ground plane includes four first grounding patches and four second grounding patches; Four first grounding patches are disposed on the side of the dielectric substrate facing the metal radiator, and are located on the periphery of the metal radiator, corresponding to the four corners of the dielectric substrate; Four second grounding patches are disposed on the side of the dielectric substrate away from the metal radiator, and the positions of the four second grounding patches correspond to the positions of the four first grounding patches so as to electromagnetically couple with the four first grounding patches.

[0012] In one embodiment, the dielectric substrate is provided with at least four first cutout portions, the at least four first cutout portions are provided around the metal radiator, and at least one first cutout portion is provided between two adjacent first grounding patches; At least two first hollow sections are symmetrically arranged about the X and / or Y directions.

[0013] In one embodiment, the dielectric substrate is further provided with at least four second cutout portions, the at least four second cutout portions are disposed in the Z direction corresponding to the metal radiator, and the positions of at least two second cutout portions are spaced apart from the positions of at least four first cutout portions in the X direction and / or Y direction. At least two second hollow sections are symmetrically arranged about the X and / or Y directions; The width of the second hollowed-out portion is smaller than the width of the first hollowed-out portion, and the length of the second hollowed-out portion is smaller than the length of the first hollowed-out portion.

[0014] The present invention also proposes a satellite communication system, including the dual-frequency navigation antenna described above.

[0015] The technical solution of the present invention comprises a dielectric substrate with metal ground planes on opposite sides along the Z direction; a metal radiator is disposed on one side of the dielectric substrate and electrically connected to the metal ground planes. The metal radiator includes a radiating body and a parasitic resonant structure. One end of the parasitic resonant structure is electrically connected to the radiating body and extends along the Z direction. The other end of the parasitic resonant structure extends along the X or Y direction and then along the Z direction and is connected to the dielectric substrate. Parasitic resonant protrusions are provided on opposite sides along the X or Y direction of the parasitic resonant structure, and the parasitic resonant protrusions extend along the X or Y direction. The radiating body is configured to support a first resonant mode to operate in a first operating frequency band. The parasitic resonant structure introduces a second resonant mode through electromagnetic coupling with the radiating body to operate in a second operating frequency band, and the second operating frequency band is higher than the first operating frequency band. This structure utilizes near-field coupling between the radiating body and the metal ground plane to achieve a low-frequency resonant mode. At the same time, it excites a high-frequency resonant mode by leveraging the additional current path and spatial distribution formed by the parasitic resonant structure and its parasitic resonant protrusions. Furthermore, it constructs orthogonal electric field components that satisfy the requirements for circular polarization through the orthogonal extension layout of the parasitic resonant protrusions. Thus, it achieves dual-frequency coverage, miniaturized layout, good radiation efficiency, and circular polarization characteristics in a single planar structure, while also taking into account low-cost manufacturing and easy assembly. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 2 This is a front view of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 3 This is a rear view of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 4 A schematic diagram of a structural embodiment of the metal radiator provided by the present invention; Figure 5 A front view of an embodiment of a metal radiator provided by the present invention; Figure 6 Rear view of an embodiment of the metal radiator provided by the present invention; Figure 7 A front view of an embodiment of the dielectric substrate provided by the present invention; Figure 8 A rear view of an embodiment of the dielectric substrate provided by the present invention; Figure 9 An unfolded view of an embodiment of the metal radiator provided by the present invention; Figure 10 S-parameter diagram of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 11 Gain and axial ratio diagram of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 12 The radiation pattern of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 13 A carrier-to-noise ratio diagram for an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 14 A carrier-to-noise ratio diagram for another embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 15 An electric field distribution diagram on a metal ground plane at the low-frequency resonant point of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 16 An electric field distribution diagram on a metal floor at a high-frequency resonant point, according to an embodiment of the dual-frequency navigation antenna provided by the present invention. Figure 17 A current distribution diagram at the low-frequency resonant point of an embodiment of the dual-frequency navigation antenna provided by the present invention; Figure 18 A current distribution diagram at the high-frequency resonant point of an embodiment of the dual-frequency navigation antenna provided by the present invention.

[0018] Explanation of icon numbers: 100. Dual-frequency navigation antenna; 10. Dielectric substrate; 101. First cutout portion; 102. Second cutout portion; 20. Metal ground plate; 21. First grounding patch; 22. Second grounding patch; 30. Metal radiator; 31. Radiating body; 311. Connecting node; 312. Radiating arm; 3121. First contour segment; 3122. Second contour segment; 32. Parasitic resonance structure; 33. Parasitic resonance protrusion; 34. Support member; 35. First metal branch; 36. Second metal branch; 37. Feeding part; 301. First radiating slot; 302. Second radiating slot; 303. Feeding slot.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] With the widespread application of GNSS (Global Navigation Satellite System) in the commercial field, the demand for miniaturized, low-cost, easy-to-assemble, and high-performance antennas is increasing, posing new challenges to antenna design. GPS (Global Positioning System), as the world's earliest satellite communication system, provides users with all-weather, most-area location and navigation information in its civilian frequency bands. Its main frequency bands include GPS L1 (center frequency 1575 MHz, bandwidth 20 MHz), L2 (center frequency 1227 MHz, bandwidth 20 MHz), and L5 (center frequency 1176 MHz, bandwidth 24 MHz). BDS (BeiDou Navigation Satellite System) is also one of the world's important satellite communication systems, with frequency bands including BeiDou B2a (center frequency 1176 MHz, bandwidth 20 MHz), B2b (center frequency 1207 MHz, bandwidth 20 MHz), and B2c (center frequency 1575 MHz, bandwidth 32.736 MHz).

[0022] To ensure navigation accuracy, antennas need to cover as many frequency bands as possible. Traditional dual-band navigation antennas often employ a double-layer patch antenna structure, where the upper and lower PCBs (Printed Circuit Boards) use different patch designs to achieve dual-band radiation, offering advantages such as low profile and miniaturization. However, the traditional dielectric substrate with a thickness of approximately 1 mm significantly reduces the radiation efficiency of patch antennas. Therefore, these antennas typically require specially customized, thicker dielectric substrates, hindering large-scale production applications. Furthermore, the double-layer structure is relatively complex to assemble and difficult to integrate into overall system designs. Ceramic antennas are another commonly used solution, but they are heavier, and achieving dual-band operation usually requires a stacked structure, increasing both cost and overall weight, thus limiting their application in many scenarios.

[0023] To address the aforementioned challenges, several factors need to be considered when designing a dual-band navigation antenna: First, how to achieve dual-band operation of the antenna and complete the dual-band design within a compact space, while ensuring that the frequency ratio of the operating frequency band meets the requirements, covers the required frequency band, and guarantees the antenna's radiation efficiency; in addition, to meet the needs of large-scale production and applicability to various application scenarios, low-cost materials must be used, and the number of installation steps and materials must be minimized as much as possible.

[0024] Therefore, this invention proposes a dual-frequency navigation antenna 100, aiming to achieve miniaturization, high radiation efficiency, and low-cost mass production of the dual-frequency navigation antenna 100.

[0025] Please see Figures 1 to 3 In one embodiment of the present invention, the dual-frequency navigation antenna 100 includes: The dielectric substrate 10 has metal ground planes 20 on both sides opposite to each other along the Z direction. A metal radiator 30 is disposed on one side of a dielectric substrate 10. The metal radiator 30 is electrically connected to a metal ground plane 20. The metal radiator 30 includes a radiating body 31 and a parasitic resonant structure 32. One end of the parasitic resonant structure 32 is electrically connected to the radiating body 31 and extends along the Z direction. The other end of the parasitic resonant structure 32 extends along the X or Y direction and then extends along the Z direction and is connected to the dielectric substrate 10. Parasitic resonant protrusions 33 are provided on opposite sides of the parasitic resonant structure 32 along the X or Y direction. The parasitic resonant protrusions 33 extend along the X or Y direction. The radiating body 31 is configured to support a first resonant mode to operate in a first operating frequency band, and the parasitic resonant structure 32 introduces a second resonant mode to operate in a second operating frequency band through electromagnetic coupling with the radiating body 31. The second operating frequency band is higher than the first operating frequency band.

[0026] In this embodiment, the dielectric substrate 10 serves as the support and dielectric carrier for the dual-band navigation antenna 100. In one embodiment, the dielectric substrate 10 is an FR-4 dielectric substrate, which can provide stable dielectric properties and is compatible with conventional printed circuit processes. The metal ground plane 20 is a surface metal layer printed on the FR-4 dielectric substrate. This helps to reduce material costs and simplify the manufacturing process, thereby supporting the goal of miniaturization.

[0027] A metal radiator 30 is disposed on one side of the dielectric substrate 10. In one embodiment, the metal radiator 30 can be formed by a single stamping process without the need for additional support structures, and can be fixed to the dielectric substrate 10 by welding, thus reducing the number of parts and simplifying the assembly process. The metal radiator 30 is electrically connected to the metal ground plane 20, that is, after the metal radiator 30 is installed on the dielectric substrate 10, it can contact the dielectric substrate 10 to achieve electrical connection. The metal radiator 30 includes a radiating body 31 and a parasitic resonant structure 32. The radiating body 31 is configured to support a first resonant mode to operate in a first operating frequency band. In particular, the radiating body 31 extends along the X direction and is spaced apart from the metal ground plane 20 along the Z direction. Compared with the stacked structure in the prior art, where the dielectric layer is arranged to separate the radiating layer and the ground layer, in this invention, since the metal ground plane 20 is directly disposed on the dielectric substrate 10, the radiating body 31 can be disposed closer to the metal ground plane 20. When the radiating body 31 approaches the metal ground plane 20, a distributed capacitance is formed between them. Especially on the side of the radiating body 31 facing the dielectric substrate 10, the distance between it and the metal ground plane 20 is smaller, and the coupling effect between them is more obvious. This is equivalent to loading a capacitor at the end of the dual-frequency navigation antenna 100. This loaded capacitor can cancel the inductive reactance of the dual-frequency navigation antenna 100 and reduce the resonant frequency, thereby achieving the ability to operate at a lower frequency band without increasing the physical size, thus achieving the purpose of miniaturization.

[0028] One end of the parasitic resonant structure 32 is electrically connected to the radiating body 31 and extends along the Z direction. The other end extends along the X or Y direction and then along the Z direction, connecting to the dielectric substrate 10. Thus, the parasitic resonant structure 32 is physically connected to the radiating body 31, but is closer to the metal ground plane 20 than it is to the radiating body 31. Because the distance between it and the metal ground plane 20 is different from that between it and the metal ground plane 20, the capacitance and inductance characteristics between them change, thereby providing an additional current path with a different current length for the current in the second operating frequency band. This current path has a shorter effective electrical length or a higher resonant frequency, thus exciting a new second resonant mode in addition to the original first resonant mode. The first resonant mode is a low-frequency resonant mode, corresponding to the first operating frequency band, while the second resonant mode is a high-frequency resonant mode, corresponding to the second operating frequency. The second operating frequency band is higher than the first operating frequency, thereby enabling the dual-frequency navigation antenna 100 to operate in both frequencies.

[0029] The parasitic resonant structure 32 has parasitic resonant protrusions 33 on opposite sides along the X or Y direction, and these protrusions extend along either direction. For example, the parasitic resonant structure 32 extends along the Z direction, then along the X direction, and then back along the Z direction, while the parasitic resonant protrusions 33 can extend along the Y direction; or, the parasitic resonant structure 32 extends along the Z direction, then along the Y direction, and then back along the Z direction, while the parasitic resonant protrusions 33 can extend along the X direction. In this way, by introducing an asymmetrical current distribution in orthogonal directions, it helps to excite two electric field components with orthogonal phases, providing conditions for achieving circular polarization.

[0030] like Figures 1 to 3 As shown, in one embodiment, when at least two parasitic resonant structures 32 are provided, the two parasitic resonant structures 32 are symmetrically arranged about the X and / or Y directions. For example, when four parasitic resonant structures 32 are provided, two of them are symmetrically arranged about the X direction, specifically, each of the two parasitic resonant structures 32 extends along the Z direction, then along the X direction and then along the Z direction again, with the parasitic resonant protrusion 33 on them extending along the Y direction. The other two parasitic resonant structures 32 are symmetrical about the Y direction, specifically, each of the two parasitic resonant structures 32 extends along the Z direction, then along the Y direction and then along the Z direction again, with the parasitic resonant protrusion 33 on them extending along the X direction. In this way, the symmetrically arranged parasitic resonant structures 32 and their parasitic resonant protrusions 33 form mutually orthogonal radiation current paths in space, which is beneficial for constructing two orthogonal electric field components with similar amplitudes and a phase difference of nearly 90 degrees, thereby supporting circularly polarized radiation characteristics.

[0031] It is particularly important to emphasize that the parasitic resonant structure 32 of the present invention can extend from the radiating body 31 along the Z direction, then along the X or Y direction, and then again along the Z direction to connect to the dielectric substrate 10. This results in a stepped impedance change between the radiating body 31 and the dielectric substrate 10, i.e., a gradual transition from a high impedance region to a low impedance region. This effectively reduces the reflection of high-frequency signals during transmission, improves energy radiation efficiency, and optimizes circular polarization performance. Since the axial ratio characterizes the amplitude consistency and phase orthogonality of the two orthogonal electric field components in the radiation field of the dual-frequency navigation antenna 100, it is very sensitive to impedance matching and phase balance. This stepped impedance transformation can broaden the frequency range that meets the 3dB axial ratio requirement in the high-frequency band, thereby significantly improving the high-frequency circular polarization bandwidth.

[0032] In summary, the technical solution of the present invention provides metal ground planes 20 on opposite sides of the dielectric substrate 10 along the Z direction; a metal radiator 30 is disposed on one side of the dielectric substrate 10 and electrically connected to the metal ground planes 20. The metal radiator 30 includes a radiating body 31 and a parasitic resonant structure 32. One end of the parasitic resonant structure 32 is electrically connected to the radiating body 31 and extends along the Z direction. The other end of the parasitic resonant structure 32 extends along the X or Y direction and then extends along the Z direction and is connected to the dielectric substrate 10. Parasitic resonant protrusions 33 are provided on opposite sides of the parasitic resonant structure 32 along the X or Y direction. The parasitic resonant protrusions 33 extend along the X or Y direction. The radiating body 31 is configured to support a first resonant mode to operate in a first operating frequency band. The parasitic resonant structure 32 introduces a second resonant mode through electromagnetic coupling with the radiating body 31 to operate in a second operating frequency band. The second operating frequency band is higher than the first operating frequency band. This structure utilizes the near-field coupling between the radiating body 31 and the metal ground plane 20 to achieve a low-frequency resonant mode. At the same time, it uses the additional current path and spatial distribution formed by the parasitic resonant structure 32 and its parasitic resonant protrusions 33 to excite a high-frequency resonant mode. Furthermore, through the extension of the parasitic resonant protrusions 33 in the orthogonal direction, it constructs orthogonal electric field components that meet the requirements of circular polarization. Thus, it achieves dual-frequency coverage, miniaturized layout, good radiation efficiency, and circular polarization characteristics in a single planar structure, while also taking into account low-cost manufacturing and easy assembly.

[0033] like Figures 4 to 6 As shown, in one embodiment, the radiating body 31 has a connecting node 311 and four radiating arms 312. The connecting node 311 is electrically connected to the parasitic resonant structure 32. The radiating arms 312 are connected to each other through the connecting node 311. The radiating arms 312 are radially distributed, and the included angle between two adjacent radiating arms 312 is 90 degrees.

[0034] In this embodiment, to achieve miniaturization of the dual-frequency navigation antenna 100, the radiating body 31 adopts an X-shaped patch. The structure of the X-shaped patch is manifested in that the radiating body 31 has a connecting node 311 and four radiating arms 312. The four radiating arms 312 extend from the connecting node 311 to the surrounding areas, forming a cross-shaped geometric configuration. The connecting node 311 is located at the center and is electrically connected to the parasitic resonant structure 32. Each radiating arm 312 is connected to each other through the connecting node 311 and is uniformly spread out radially.

[0035] Compared to square patches, under the condition of the same circumscribed circle diameter (meaning the diameter of the largest circular area that can be inscribed within the overall outline of the radiating body 31 remains consistent), the X-shaped patch, due to its arm-like structure extending diagonally, ensures that the current path is no longer confined to a straight edge. Instead, it propagates outward from the connecting node 311 along the radiating arm 312 and reflects back at the end of the radiating arm 312, thus lengthening the overall current path. This helps to reduce the low-frequency resonant frequency, achieving miniaturization of the dual-frequency navigation antenna 100 without increasing the antenna's physical size. Since adjacent radiating arms 312 maintain a 90-degree angle, the overall structure possesses good rotational symmetry in the horizontal plane, which helps to excite orthogonal current components with similar amplitudes and phases differing by 90 degrees, providing a foundation for the dual-frequency navigation antenna 100 to achieve circularly polarized radiation. Simultaneously, the radial distribution of each radiating arm 312 allows the current to radiate uniformly in multiple directions, which is beneficial for improving the pattern symmetry and impedance stability of the dual-frequency navigation antenna 100.

[0036] like Figures 4 to 6 As shown, in one embodiment, each radiating arm 312 has a first profile segment 3121 and a second profile segment 3122 at the end away from the connecting node 311. The first contour segment 3121 extends along the X direction; The second contour segment 3122 extends along the Y direction; The first contour segment 3121 and the second contour segment 3122 are each provided with a support member 34, which extends along the Z direction and is connected to the dielectric substrate 10.

[0037] In this embodiment, the ends of each radiating arm 312 extend along mutually orthogonal X and Y directions via a first contour segment 3121 and a second contour segment 3122, respectively, forming an L-shaped edge structure. This structure helps to introduce orthogonally oriented current components at the ends of the radiating arms 312, further enhancing the ability of the dual-frequency navigation antenna 100 to achieve circularly polarized radiation. The support members 34 configured on the first contour segment 3121 and the second contour segment 3122 extend along the Z direction and connect to the dielectric substrate 10. These support members not only provide mechanical fixation for the metal radiator 30 but also adjust the local spacing between the radiating arm 312 and the metal ground plane 20 by controlling the position of the support members 34, thereby affecting the impedance matching and high-frequency resonance characteristics of the dual-frequency navigation antenna 100. Simultaneously, the arrangement of the support members 34 ensures that the radiating arm 312 maintains a physically stable relative position with the dielectric substrate 10, which is beneficial for maintaining consistent radiation performance.

[0038] like Figures 4 to 6 As shown, in one embodiment, each radiating arm 312 is provided with a first metal branch 35 and a second metal branch 36. The first metal branch 35 of one of the two adjacent radial arms 312 is electrically connected to the second metal branch 36 of the other radial arm 312. One end of the first metal branch 35 extends along the X direction to form a first radiation groove 301 between it and the corresponding radiation arm 312, and the other end of the first metal branch 35 extends along the Z direction and is connected to the dielectric substrate 10. One end of the second metal branch 36 extends along the Y direction to form a second radiation groove 302 between it and the corresponding radiation arm 312, and the other end of the second metal branch 36 extends along the Z direction and is connected to the dielectric substrate 10.

[0039] In this embodiment, to reduce the frequency ratio between the first operating frequency band and the second operating frequency band, a first metal stub 35 and a second metal stub 36 are added to each radiating arm 312, and the first metal stub 35 of one radiating arm 312 is electrically connected to the second metal stub 36 of the other radiating arm 312 via a microstrip line. This connection method ensures that the current path within the first operating frequency band is no longer confined to the interior of a single radiating arm 312, but rather forms a loop extending to adjacent radiating arms 312 through cross-arm connections.

[0040] Since the first metal branch 35 extends along the X direction and forms a first radiation slot 301 with the corresponding radiation arm 312, and the second metal branch 36 extends along the Y direction and forms a second radiation slot 302 with the corresponding radiation arm 312, the two are orthogonally distributed in space, and their cross-arm electrical connection further guides the low-frequency current to flow through the cross-coupling path formed by the first metal branch 35 and the second metal branch 36.

[0041] Meanwhile, the high-frequency resonance is mainly excited by the parasitic resonant structure 32, and its current path is concentrated near the parasitic resonant structure 32, while the low-frequency current is directed away from the high-frequency resonant point due to the aforementioned cross-arm connection. Thus, the current paths corresponding to the low-frequency and high-frequency resonant operating points are physically separated, avoiding the sharing of the same high-impedance or high-field-strength region. This helps to adjust the relative relationship between the two resonant frequencies, thereby reducing the frequency ratio between the first and second operating frequency bands, allowing the dual-frequency navigation antenna 100 to more flexibly cover the required navigation frequency band within a compact structure.

[0042] like Figures 4 to 6 As shown, in one embodiment, each of two adjacent radiation arms 312 of the four radiation arms 312 is provided with a feed slot 303, and the included angle between the two feed slots 303 is 90 degrees. The metal radiator 30 also includes two power feeding sections 37. One end of each power feeding section 37 is connected to the connection node 311, and the other end extends along the Z direction and is fixed to the side of the dielectric substrate 10 away from the metal radiator 30, and is electrically connected to the metal ground plane 20.

[0043] In this embodiment, two feed sections 37 excite the metal radiator 30 through a connecting node 311. Since the two feed slots 303 are located on adjacent radiating arms 312 with an included angle of 90 degrees, the two feed signals are spatially orthogonal, thereby exciting current components with similar amplitudes and a phase difference of approximately 90 degrees in the radiating body 31. This feeding method helps to form a circularly polarized radiation field with a stable rotation direction. Simultaneously, using the connecting node 311 as a common feed reference point ensures good symmetry between the two feed paths, which is beneficial for maintaining impedance matching and polarization purity of the dual-frequency navigation antenna 100 in the first operating frequency band.

[0044] like Figure 7 and Figure 8 As shown, in one embodiment, the dielectric substrate 10 is a rectangular substrate; the metal ground plane 20 includes four first grounding patches 21 and four second grounding patches 22; Four first grounding patches 21 are disposed on the side of the dielectric substrate 10 facing the metal radiator 30, and are located on the periphery of the metal radiator 30, corresponding to the four corners of the dielectric substrate 10. Four second grounding patches 22 are disposed on the side of the dielectric substrate 10 away from the metal radiator 30. The positions of the four second grounding patches 22 correspond to the positions of the four first grounding patches 21, so as to electromagnetically couple with the four first grounding patches 21.

[0045] In this embodiment, to mitigate potential losses caused by strong coupling between the dielectric substrate 10 and the metal radiator 30, four first grounding patches 21 are provided on the side of the dielectric substrate 10 facing the metal radiator 30. The four first grounding patches 21 are located around the metal radiator 30 and correspond to the four corners of the dielectric substrate 10. Their arrangement utilizes the geometric symmetry of the rectangular substrate to provide distributed grounding points without obstructing the main radiation area of ​​the radiating body 31. The four first grounding patches 21, through electromagnetic coupling, excite four second grounding patches 22 at corresponding positions on the other side of the dielectric substrate 10, so that the effective radiation area of ​​the metal ground plane 20 is no longer limited to a single surface, but expands the overall conductor area participating in radiation through the synergistic effect of the patches on both sides. Compared to the traditional single-layer metal ground plane 20 design, this configuration helps improve the radiation efficiency of the dual-frequency navigation antenna 100.

[0046] like Figure 7 and Figure 8 As shown, in one embodiment, the dielectric substrate 10 is provided with at least four first cutout portions 101, and the at least four first cutout portions 101 are provided around the metal radiator 30. Two adjacent first grounding patches 21 are provided with at least one first cutout portion 101 at intervals. At least two first hollowed-out portions 101 are symmetrically arranged about the X and / or Y directions.

[0047] In this embodiment, to further improve the radiation efficiency of the dual-frequency navigation antenna 100, multiple first cutouts 101 are provided in the dielectric substrate 10 region surrounding the metal radiator 30 without affecting structural stability. The multiple first cutouts 101 are located between adjacent first ground patches 21, and their symmetrical arrangement maintains the electromagnetic balance of the overall structure. By reducing the distribution of dielectric material in non-critical support areas, the equivalent loss tangent of the dielectric substrate 10 is effectively reduced, thereby weakening the absorption of electromagnetic waves by the dielectric and contributing to improved radiation efficiency of the dual-frequency navigation antenna 100.

[0048] like Figure 7 and Figure 8 As shown, in one embodiment, the dielectric substrate 10 is further provided with at least four second cutout portions 102, the at least four second cutout portions 102 are disposed in the Z direction corresponding to the metal radiator 30, and the positions of at least two second cutout portions 102 are disposed at intervals corresponding to the positions of at least four first cutout portions 101 in the X direction and / or Y direction. At least two second hollowed-out portions 102 are symmetrically arranged about the X and / or Y directions; The width of the second hollow part 102 is smaller than the width of the first hollow part 101, and the length of the second hollow part 102 is smaller than the length of the first hollow part 101.

[0049] In this embodiment, the high-frequency radiation performance of the dual-frequency navigation antenna 100 is further optimized by providing a plurality of smaller second cutout portions 102 on the dielectric substrate 10 corresponding to the area directly below the metal radiator 30. The plurality of second cutout portions 102 and the peripheral first cutout portions 101 are arranged in a correspondingly spaced manner in the X and / or Y directions, and maintain symmetry to maintain the electromagnetic consistency of the structure.

[0050] Since the second hollow portion 102 is located within the projection area of ​​the metal radiator 30, its small size can reduce the dielectric loading effect while avoiding excessive weakening of the support strength, thereby effectively reducing the local dielectric constant and loss in the high-frequency band and improving the radiation efficiency of the second resonant mode excited by the parasitic resonant structure 32.

[0051] Figures 1 to 8A schematic diagram of the dual-frequency navigation antenna 100 and its components provided by this invention is shown. The dual-frequency navigation antenna 100 of this invention includes a metal radiator 30 and an FR4 dielectric substrate 10 with double-sided copper traces. The metal radiator 30 is fixed to the dielectric substrate 10 by soldering, requiring no additional support structure. The dual-frequency navigation antenna 100 is fed through two pins inside the metal radiator 30. The second ground patch 22 of the metal radiator 30 and the internal stamped plane provide low-frequency and high-frequency resonance for the dual-frequency navigation antenna 100, respectively. The design of the upper and lower surfaces of the FR4 dielectric substrate 10, while maintaining a miniaturized design, rationally utilizes the electromagnetic coupling effect, effectively increasing the equivalent electrical size of the metal ground plane 20 of the dual-frequency navigation antenna 100 and improving radiation efficiency.

[0052] Figure 9 The diagram shows a flattened view of the metal radiator 30, where dr1 = 4.9 mm, dr2 = 2.1 mm, dr3 = 4.2 mm, Wr0 = 42.2 mm, Wr1 = 2.9 mm, Wr2 = 3.1 mm, Wr3 = 2.7 mm, Wr4 = 2.5 mm, Wr5 = 9.7 mm, Lr1 = 11.3 mm, Lr2 = 16.4 mm, Lr3 = 9.4 mm, Wmid = 10.72 mm, and Lmid = 9 mm. These dimensions collectively define the geometric layout of the metal radiator 30 and its components. Since there is no interference between the parts, it can be formed by stamping, effectively reducing production costs and meeting industrial production needs.

[0053] Figure 10 The S-parameter results for the dual-frequency navigation antenna 100 proposed in this invention are shown. In the frequency bands of 1.1 to 1.24 GHz and 1.45 to 1.7 GHz, S11 is less than... 10dB.

[0054] Figure 11 The results show the gain and axial ratio of the dual-band navigation antenna 100. In the 1.164–1.237 GHz band, the right-hand circularly polarized gain is greater than 2.03 dBic. In the 1.559–1.591 GHz band, the right-hand circularly polarized gain is greater than 3.34 dBic. The measured axial ratio of the dual-band navigation antenna 100 is close to the simulation results, with an axial ratio less than 3 dB in the 1.1–1.23 GHz and 1.53–1.61 GHz bands.

[0055] Figure 12The radiation pattern of the dual-frequency navigation antenna 100 is shown. Due to unavoidable manufacturing errors in the physical sample and losses introduced by the dielectric substrate 10, patch capacitors, and transmission lines, there are slight differences between the measured radiation pattern and the simulation results, but the basic trends remain consistent. At 1.175 GHz, the 3dB beamwidth on the XOZ plane is approximately 97.1 degrees, and the 3dB beamwidth on the YOZ plane is approximately 97.3 degrees. At 1.225 GHz, the 3dB beamwidth on the XOZ plane is approximately 96.3 degrees, and the 3dB beamwidth on the YOZ plane is approximately 96.1 degrees. At 1.575 GHz, the 3dB beamwidth on the XOZ plane is approximately 91.5 degrees, and the 3dB beamwidth on the YOZ plane is approximately 91.7 degrees. These beamwidths meet the coverage requirements of satellite communication.

[0056] Figure 13 and Figure 14 The carrier-to-noise ratio (CNR) results of the dual-frequency navigation antenna 100 are shown. The CNR of most satellite signals is greater than 30 dB, meeting the signal quality requirements for positioning applications.

[0057] Figure 15 The electric field distribution on the floor at the low-frequency resonant point is shown.

[0058] Figure 16 The electric field distribution on the ground plane at the high-frequency resonant point is shown. By proposing a defective ground structure, the surrounding ground plane structure is excited, thereby increasing the equivalent ground plane area and thus improving the radiation efficiency of the dual-frequency navigation antenna 100.

[0059] Figure 17 The current distribution at the low-frequency resonant point is shown.

[0060] Figure 18 The current distribution at the high-frequency resonant point is shown. It can be seen that the current at the low-frequency resonant point passes through the metal stub and microstrip line structure, but not through point P. However, the current at the high-frequency resonant point passes through point P. This phenomenon indicates that the proposed dual-frequency navigation antenna 100 achieves separation of the high- and low-frequency operating current paths, thus allowing for flexible control of the two operating frequencies.

[0061] The present invention also proposes a satellite communication system, which includes a dual-frequency navigation antenna 100. The specific structure of the dual-frequency navigation antenna 100 is as described in the above embodiments. Since the satellite communication system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0062] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A dual frequency navigation antenna, characterized in that, include: A dielectric substrate, wherein metal ground planes are respectively provided on two opposite sides along the Z direction; A metal radiator is disposed on one side of the dielectric substrate and electrically connected to the metal ground plane. The metal radiator includes a radiating body and a parasitic resonant structure. One end of the parasitic resonant structure is electrically connected to the radiating body and extends along the Z direction. The other end of the parasitic resonant structure extends along the X or Y direction and then extends along the Z direction and is connected to the dielectric substrate. Parasitic resonant protrusions are provided on opposite sides of the parasitic resonant structure along the X or Y direction. The parasitic resonant protrusions extend along the X or Y direction. The radiating body is configured to support a first resonant mode to operate in a first operating frequency band, and the parasitic resonant structure introduces a second resonant mode to operate in a second operating frequency band through electromagnetic coupling with the radiating body, the second operating frequency band being higher than the first operating frequency band.

2. The dual frequency navigation antenna of claim 1, wherein, The metal radiator is welded to the dielectric substrate.

3. The dual frequency navigation antenna of claim 1, wherein, The radiating body has a connecting node and four radiating arms. The connecting node is electrically connected to the parasitic resonant structure. The radiating arms are connected to each other through the connecting node. The radiating arms are radially distributed, and the included angle between two adjacent radiating arms is 90 degrees.

4. The dual frequency navigation antenna of claim 3, wherein, Each of the radial arms has a first profile segment and a second profile segment at the end away from the connection node. The first contour segment extends along the X direction; The second contour segment extends along the Y direction; The first contour segment and the second contour segment are each provided with a support member, which extends along the Z direction and is connected to the dielectric substrate.

5. The dual frequency navigation antenna of claim 3, wherein, Each of the aforementioned radiating arms is provided with a first metal branch and a second metal branch; The first metal stub of one of two adjacent radiating arms is electrically connected to the second metal stub of the other radiating arm; One end of the first metal branch extends along the X direction to form a first radiation groove with the corresponding radiation arm, and the other end of the first metal branch extends along the Z direction and is connected to the dielectric substrate. One end of the second metal branch extends along the Y direction to form a second radiation groove between itself and the corresponding radiation arm, and the other end of the second metal branch extends along the Z direction and is connected to the dielectric substrate.

6. The dual-frequency navigation antenna as described in claim 3, characterized in that, Each of the four radiating arms has a feeding slot for two adjacent radiating arms, and the included angle between the two feeding slots is 90 degrees. The metal radiator further includes two power feeding sections, one end of each power feeding section is connected to the connection node, and the other end extends along the Z direction and is fixed to the side of the dielectric substrate away from the metal radiator, and is electrically connected to the metal ground.

7. The dual-frequency navigation antenna as described in any one of claims 3-6, characterized in that, The dielectric substrate is a rectangular substrate; the metal ground plane includes four first grounding patches and four second grounding patches; Four first grounding patches are disposed on the side of the dielectric substrate facing the metal radiator, and are located on the periphery of the metal radiator, corresponding to the four corners of the dielectric substrate; Four second grounding patches are disposed on the side of the dielectric substrate away from the metal radiator, and the positions of the four second grounding patches correspond to the positions of the four first grounding patches so as to electromagnetically couple with the four first grounding patches.

8. The dual-frequency navigation antenna as described in claim 7, characterized in that, The dielectric substrate is provided with at least four first cutout portions, and the at least four first cutout portions are provided around the metal radiator. Each two adjacent first grounding patches are provided with at least one first cutout portion at intervals. At least two first hollow sections are symmetrically arranged about the X and / or Y directions.

9. The dual-frequency navigation antenna as described in claim 8, characterized in that, The dielectric substrate is further provided with at least four second cutout portions, which are arranged in the Z direction corresponding to the metal radiator. The positions of at least two second cutout portions and the positions of at least four first cutout portions are arranged at intervals in the X and / or Y directions respectively. At least two second hollow sections are symmetrically arranged about the X and / or Y directions; The width of the second hollowed-out portion is smaller than the width of the first hollowed-out portion, and the length of the second hollowed-out portion is smaller than the length of the first hollowed-out portion.

10. A satellite communication system, characterized in that, Includes the dual-frequency navigation antenna as described in any one of claims 1-9.

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