A tri-band shared metasurface antenna

Abstract

This invention relates to the field of antenna technology and provides a three-band shared metasurface antenna, comprising a metasurface portion, a printed dipole portion, and a circularly polarized antenna array portion arranged sequentially from top to bottom. Gaps are reserved between the metasurface portion and the printed dipole portion, and between the printed dipole portion and the circularly polarized antenna array portion. In the low-frequency band, the metasurface portion of the antenna provides a high dielectric constant, enabling its use in S / C-band terrestrial 5G communication. In the mid-frequency band, the metasurface portion supports surface wave propagation, and the supported surface waves can diffract a dual-quasi-end-fire pattern at the edges for C-band V2X communication. In the high-frequency band, the metasurface portion exhibits the performance of a transmissive frequency-selective surface, thus providing a transmission window for the side-fired beam generated by the circularly polarized antenna array below. This circularly polarized radiation can be used for K-band low-Earth orbit satellite communication.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and more specifically, to a three-band shared metasurface antenna. Background Technology

[0002] With the rapid development of autonomous driving technology, antennas installed in automobiles are required to be multifunctional to meet various connectivity needs. On the one hand, the vision for the next generation of mobile communication systems is to integrate terrestrial mobile communication and satellite communication systems to build a ubiquitous communication network architecture connecting air, space, and sea. In this context, vehicle-mounted antennas are required not only to interconnect with S / C band devices such as terrestrial 5G base stations, but also to directly connect with low-Earth orbit satellite constellations operating in the Ku / K / Ka bands in remote areas. This necessitates that vehicle-mounted communication antennas possess both S / C band linear polarization radiation and Ku / K / Ka band circular polarization radiation performance. On the other hand, dedicated short-range communication (DSM) and vehicle-to-everything (V2X) are two key communication standards used in V2X systems. DSM, operating in the 5.85–5.925 GHz band, supports direct communication between vehicles and other transportation equipment or roadside units, while cellular V2X, operating in the 5.905–5.925 GHz band, enables vehicles to connect with each other via base stations. To simultaneously achieve short-range communication and cellular V2X communication, the antenna needs to exhibit quasi-end-to-far-field performance within the 5.85–5.925 GHz frequency band. In summary, to achieve high-quality autonomous driving systems, there is an urgent need for high-performance antennas with both heterogeneous frequency and polarization capabilities. Although the simplest way to achieve these multi-functional requirements is to integrate multiple antennas simultaneously, this approach has drawbacks such as occupying a large space and the difficulty in eliminating coupling between antennas.

[0003] Co-structure antennas can integrate two or more cross-band antennas within a single effective structure, providing a compact and space-efficient solution for the aforementioned multifunctional requirements. In the published literature, researchers have proposed various co-structure antennas for automotive communication systems.

[0004] The literature [Y.-X. Sun, KW Leung, and K. Lu, “Compact dual microwave / millimeter-wave planar shared-aperture antenna for vehicle-to-vehicle / 5G communications,” IEEE Trans. Veh. Technol., vol. 70, no. 5, pp. 5071-5076, May 2021] introduces a dual-port design that includes a planar magnetoelectric dipole antenna and a parallel plate resonator antenna. This design can operate simultaneously in the 5.30–8.08 GHz range for vehicle-to-vehicle (V2V) communication and in the 27.15–29.02 GHz range for millimeter-wave 5G connectivity. The literature [ZXXia, KWLeung, P.Gu and R.Chen, “3-D-printed wideband high-efficiency dual-frequency antenna for vehicular communications,” IEEE Trans. Veh. Technol., vol. 71, no. 4, pp. 3457-3469, Apr. 2022] proposes a 3D-printed co-structure antenna incorporating a dielectric resonator radiator and a dielectric lens radiator. The two types of radiators operate in the S-band for vehicle-to-ground base station connections and the X-band for low-Earth orbit satellite communications, respectively. A common drawback of both of these co-structure antenna designs is their relatively low actual antenna gain, especially in the low-frequency band. Furthermore, these designs lack the multi-functional attributes of hetero-frequency and hetero-directional polarization.

[0005] Besides the aforementioned dual-band / multi-band applications, co-structure antennas are also used in the design of radiation patterns and polarization diversity. The literature [W. Wang and Y. Zheng, “Wideband gain enhancement of a dual-polarized MIMOvehicular antenna,” IEEE Trans. Veh. Technol., vol. 70, no. 8, pp. 7897-7907, Aug. 2021] designed a dual-band high-gain co-structure antenna, which can simultaneously generate multi-beam radiation for Ka-band line-of-sight communication and high-gain side-firing beams for C-band 5G communication; however, the antenna gain differs significantly between the two bands.

[0006] In recent years, co-structure antenna designs with multi-frequency, multi-directional, and multi-polarization capabilities have been introduced into automotive communication systems. The literature [J. Zhu, Y. Yang, S. Li, S. Liao, and Q. Xue, “Dual-Band dual circularlypolarized antenna array using FSS-Integrated polarization rotation AMC ground for vehicle satellite communications,” IEEE Trans. Veh. Technol., vol. 68, no. 11, pp. 10742-10751, Nov. 2019] introduces a dual-band, three-polarized co-structure antenna with diverse radiation patterns. This antenna can radiate a side-firing pattern for 5G communication and an omnidirectional pattern for V2X communication. However, a drawback of this antenna is its relatively low gain within the dual-band. Therefore, achieving a co-structure antenna design with multi-band high gain, heterogeneous frequency and polarization is both urgently needed and presents significant challenges for automotive communication systems. Summary of the Invention

[0007] The purpose of this invention is to provide a tri-band shared metasurface antenna with advantages such as hetero-frequency and hetero-directionality, hetero-frequency and hetero-polarization, and high structural reuse efficiency, so as to at least overcome the technical problems that existing vehicle-mounted antennas cannot simultaneously realize vehicle-to-base station communication, V2X communication, and vehicle-to-K-band satellite communication.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A three-band shared metasurface antenna includes a metasurface portion, a printed dipole portion, and a circularly polarized antenna array portion arranged sequentially from top to bottom. Gaps are reserved between the metasurface portion and the printed dipole portion, and between the printed dipole portion and the circularly polarized antenna array portion.

[0010] The metasurface portion includes a dielectric substrate A and a metasurface unit array, wherein the metasurface unit array is disposed on the dielectric substrate A;

[0011] The printed dipole portion includes a dielectric substrate B and a dipole patch, wherein the dipole patch is printed on the top surface of the dielectric substrate B and has a port E;

[0012] The circularly polarized antenna array includes a circularly polarized antenna array, a dielectric substrate C, a dielectric substrate D, and a feeding structure. The circularly polarized antenna array is disposed on the dielectric substrate C, the dielectric substrate D is disposed below the dielectric substrate C, and the feeding structure is printed on the bottom surface of the dielectric substrate D and has a port F.

[0013] In some possible embodiments, the metasurface unit array consists of 13×13 metasurface units arranged periodically;

[0014] The metasurface unit includes two windmill-shaped patches and a short-circuit probe. The two windmill-shaped patches are printed on the upper and lower surfaces of the dielectric substrate A, respectively, and the two windmill-shaped patches are connected by the short-circuit probe.

[0015] In some possible embodiments, the relative permittivity of the dielectric substrate A is 3.5.

[0016] In some possible embodiments, the relative permittivity of the dielectric substrate B is 3.5.

[0017] In some possible embodiments, the circularly polarized antenna array consists of 2×2 circularly polarized antennas arranged in a periodic pattern.

[0018] In some possible embodiments, the relative permittivity of the dielectric substrate C is 3.5, and the relative permittivity of the dielectric substrate D is 2.2.

[0019] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0020] The tri-band shared metasurface antenna provided by this invention has advantages such as heterogeneous frequency and directionality, heterogeneous frequency and polarization, and high structural reuse efficiency. In the low-frequency band, the metasurface portion has a high dielectric constant, which enables its use in S / C band terrestrial 5G communication. In the mid-frequency band, the metasurface portion can support the propagation of surface waves, and the supported surface waves can diffract a dual-quasi-end-fire pattern at the edge for C-band V2X communication. In the high-frequency band, the metasurface portion can exhibit the performance of a transmissive frequency-selective surface, thus providing a transmission window for the side-fired beam generated by the circularly polarized antenna array below. This circularly polarized radiation can be used for K-band low-Earth orbit satellite communication. Attached Figure Description

[0021] Figure 1 This is a side view of a three-band shared metasurface antenna provided in an embodiment of the present invention;

[0022] Figure 2 for Figure 1 Schematic diagram of section AA;

[0023] Figure 3Top and side views of the metasurface unit provided in the embodiments of the present invention;

[0024] Figure 4 for Figure 1 Schematic diagram of the BB section;

[0025] Figure 5 for Figure 1 A schematic diagram of the C-section;

[0026] Figure 6 for Figure 1 Schematic diagram of the DD section;

[0027] Figure 7 A bottom view of the dielectric substrate D of the circularly polarized antenna array portion provided in an embodiment of the present invention;

[0028] Figure 8 The S-parameter curve of port E of the dipole patch provided in the embodiment of the present invention;

[0029] Figure 9 The S-parameter curve of port F of the power supply structure provided in the embodiment of the present invention;

[0030] Figure 10 Radiation gain curve of port E of the dipole patch provided in an embodiment of the present invention;

[0031] Figure 11 Radiation gain curve of port F of the feeding structure provided in the embodiment of the present invention;

[0032] Figure 12 Axis ratio curve of a circularly polarized antenna array provided in an embodiment of the present invention;

[0033] Figure 13 The radiation pattern of port E of the dipole patch provided in this embodiment of the invention is shown at 3.9 GHz.

[0034] Figure 14 The radiation pattern of port E of the dipole patch provided in this embodiment of the invention is shown at 4.5 GHz.

[0035] Figure 15 The radiation pattern of port E of the dipole patch provided in this embodiment of the invention is shown at 5.8 GHz.

[0036] Figure 16 The radiation pattern of port F of the feed structure provided in this embodiment of the invention at 20.0 GHz;

[0037] Figure 17 The radiation pattern of port F of the power supply structure provided in this embodiment of the invention is shown at 21.0 GHz.

[0038] Icons: 10-Metasurface section, 11-Dielectric substrate A, 12-Metasurface unit, 121-Windmill-shaped patch, 122-Short-circuit probe, 20-Printed dipole section, 21-Dielectric substrate B, 22-Dipole patch, 22a-Port E, 30-Circularly polarized antenna array section, 31-Circularly polarized antenna array, 32-Dielectric substrate C, 33-Dielectric substrate D, 34-Feed structure, 34a-Port F. Detailed Implementation

[0039] Example

[0040] Please refer to Figures 1 to 7 This embodiment provides a three-band shared metasurface antenna, specifically a three-band high-gain antenna with diverse radiation patterns and polarizations based on a shared metasurface structure. Please refer to... Figure 1 The three-band shared metasurface antenna includes a metasurface portion 10, a printed dipole portion 20, and a circularly polarized antenna array portion 30 arranged sequentially from top to bottom. Gaps are reserved between the metasurface portion 10 and the printed dipole portion 20, and between the printed dipole portion 20 and the circularly polarized antenna array portion 30.

[0041] In this embodiment, combined with Figure 2 As shown, the metasurface portion 10 includes a dielectric substrate A11 and a metasurface unit array, which is disposed on the dielectric substrate A11. Preferably, in this embodiment, the metasurface unit array is composed of 13×13 metasurface units 12 arranged in a periodic manner.

[0042] Specifically, the metasurface unit 12 includes two windmill-shaped patches 121 with identical shapes and parameters, and a short-circuit probe 122. The specific structure and printing position of the two windmill-shaped patches 121 are as follows: Figure 3 As shown, two windmill-shaped patches 121 are printed on the upper and lower surfaces of the dielectric substrate A11, respectively, and the two windmill-shaped patches 121 are connected by a short-circuit probe 122. It can be understood that in this embodiment, a single metasurface unit 12 has multiple short-circuit probes 122, and the multiple short-circuit probes 122 are arrayed to connect the two windmill-shaped patches 121 of the metasurface unit 12 respectively.

[0043] Based on this design, in the 3.5–4.5 GHz frequency band, the metasurface portion 10 exhibits a high dielectric constant (the relative dielectric constant is approximately the square of the refractive index), thus it can be used for the design of metasurface antennas; in the 5.85–5.925 GHz frequency band, the metasurface portion 10 has no electromagnetic bandgap, thus enabling the propagation of surface waves; in the 20.0–22.1 GHz frequency band, the metasurface portion 10 has electromagnetic transmission performance (transmission coefficient > -0.3 dB) and steep transmission curve fading characteristics on both sides of the passband, thus it can be used for the transmission of circularly polarized antenna array 31.

[0044] In this embodiment, the printed dipole portion 20 is used to excite the S / C band metasurface antenna and the surface wave antenna. The printed dipole portion 20 includes a dielectric substrate B21 and a dipole patch 22, combined with... Figure 4 As shown, the dipole patch 22 is printed on the top surface of the dielectric substrate B21, and the dipole patch 22 has a port E22a. Preferably, the dipole patch 22 is printed in the middle of the dielectric substrate B21 and directly opposite the metasurface portion 10.

[0045] In this embodiment, refer to Figure 1 The circularly polarized antenna array section 30 includes a circularly polarized antenna array 31, a dielectric substrate C32, a dielectric substrate D33, and a feeding structure 34 (i.e., a feeding network). The circularly polarized antenna array 31 is disposed on the dielectric substrate C32. Preferably, it is combined with... Figure 5 and Figure 6 As shown, the circularly polarized antenna array 31 in this embodiment is composed of 2×2 circularly polarized antennas arranged periodically. The radiating element used in the circularly polarized antenna array 31 composed of 2×2 circularly polarized antennas is a slot-coupled fed substrate integrated waveguide cavity slot antenna, whose cavity structure is mounted on a dielectric substrate C32. Preferably, the 2×2 circularly polarized antennas are arranged in a ring array on the dielectric substrate C32. The dielectric substrate D33 is disposed below the dielectric substrate C32, and the feeding structure 34 is printed on the bottom surface of the dielectric substrate D33. The feeding structure 34 has a port F34a to excite the circularly polarized antenna array 31 through the feeding structure 34.

[0046] It should be noted that in this embodiment, the dielectric substrate A11 of the metasurface portion 10, the dielectric substrate B21 of the printed dipole portion 20, and the dielectric substrates C32 and D33 of the circularly polarized antenna array portion 30 can all be made of domestically produced Wangling board material. Meanwhile, the relative permittivity of dielectric substrates A11, B21, and C32 is 3.5, while the relative permittivity of dielectric substrate D33 is 2.2.

[0047] The three-band shared metasurface antenna provided in this embodiment integrates three types of antenna radiation: metasurface antenna radiation, surface wave antenna radiation, and circularly polarized array antenna radiation transmitted through a frequency-selective surface. Correspondingly, the metasurface portion 10 shared by the three types of antenna radiation can exhibit the performance of high dielectric constant, surface wave guide, and transmission-type frequency-selective surface in different frequency bands. The metasurface antenna and surface wave antenna are both excited by the dipole patch 22 of the printed dipole portion 20, while the circularly polarized antenna array 31 is excited by the feed structure 34 of the circularly polarized antenna array portion 30. Furthermore, the circularly polarized antenna array portion 30 can act as a reflector for the surface wave antenna, thereby forming a quasi-end-fire radiation effect.

[0048] Specifically, when port E22a of dipole patch 22 is operational and port F34a of feed structure 34 is connected to a matching load, this tri-band shared metasurface antenna can excite metasurface antenna resonance in the 3.5–4.5 GHz band and surface wave antenna resonance in the 5.85–5.925 GHz band. The former generates a broadband side-fire beam for vehicle-to-ground base station communication, and the latter generates a dual-quasi-end-fire beam for V2X communication. When port E22a of dipole patch 22 is connected to a matching load and port F34a of feed structure 34 is operational, this tri-band shared metasurface antenna excites circularly polarized radiation of the substrate integrated waveguide cavity slot antenna in the 20.0–22.1 GHz band through the continuously rotating feed structure 34 printed on the bottom of dielectric substrate D33. This radiated beam is transmitted through the metasurface portion 10 to realize vehicle-to-satellite communication.

[0049] To further verify the reflection and radiation performance of the three-band shared metasurface antenna provided in this embodiment, the antenna was also fabricated and tested in this embodiment. The test results are as follows: Figures 8 to 17 As shown.

[0050] in, Figure 8 The S-parameter curve of port E22a of dipole patch 22 is shown. Figure 9 The S-parameter curve of port F34a of the power supply structure 34 is shown. Combined with... Figure 8 and Figure 9 The test results show that in the low-frequency band, this three-band shared metasurface antenna has two operating frequency bands. The first operating frequency band is a dual-resonance band with resonant frequencies of 3.9GHz and 4.5GHz, and a bandwidth of 3.65–4.58GHz, which can cover part of the 5G operating frequency. The second operating frequency band has a bandwidth of 5.70–5.96GHz, which can cover dedicated short-range communication and cellular V2X bands. Furthermore, within the entire low-frequency operating bandwidth, the port isolation is higher than 35dB. In the high-frequency band, such as... Figure 9As shown, the measured -10-dB impedance bandwidth is 19.45~21.85GHz, which can cover the K-band satellite communication frequency band well, and the isolation between ports is higher than 14.5dB.

[0051] Meanwhile, the radiation gain curves of the final antenna in the low-frequency and high-frequency bands obtained through simulation and testing are shown below. Figure 10 and Figure 11 As shown in the figure. In the low-frequency band, the peak gain variation range in the first operating frequency band is 7.8–8.5 dBi, which is basically consistent with the simulation results. The peak gain variation range in the second operating frequency band is 4.5–5.75 dBi. It should be noted that since the radiation pattern in the second operating frequency band is bi-directional end-fired, while that in the first operating frequency band is side-fired, the peak gain in the second frequency band is approximately 3 dB lower than that in the first frequency band. In the high-frequency band, the axial ratio curve of the circularly polarized antenna is shown in the figure. Figure 12 As shown, based on the test results, the antenna's 3-dB axial ratio bandwidth is 19.8–21.5 GHz. Combined with the aforementioned impedance bandwidth, the operating bandwidth of the circularly polarized antenna is 19.8–21.5 GHz. Within this frequency band, [the antenna's performance is determined by...]. Figure 11 It can be seen that the side-shot gains obtained from simulation and testing are 5.8–8.9 dBi and 6.15–8.45 dBi, respectively.

[0052] Furthermore, when port E22a of dipole patch 22 is operational and port F34a of feed structure 34 is connected to a matched load, the antenna operates in the low-frequency band. The radiation patterns of the antenna at the two resonant frequencies of 3.9 GHz and 4.5 GHz are as follows: Figure 13 and Figure 14 As shown in the figure, the antenna exhibits good side-firing and low cross-polarization performance; and within the second operating frequency band, as... Figure 15 As shown, the antenna produces a dual-quasi-end-fire radiation pattern with good low sidelobes and low cross-polarization performance. When port F34a of the feed structure 34 operates alone, the antenna operates in the high-frequency band, and the far-field radiation pattern of the antenna in this band is as follows. Figure 16 and Figure 17 As shown, it can be seen that the antenna maintains good left-hand circular polarization lateral radiation under the surface structure with selected loading frequency, while the cross-polarization and back radiation are relatively low.

[0053] Therefore, the three-band shared metasurface antenna provided in this embodiment can serve as the radiation source of a broadband metasurface antenna, the surface wave guide of a surface wave antenna, and the frequency selective surface of a circularly polarized antenna array 31 in three frequency bands, respectively. By placing a dipole patch 22 below the metasurface portion 10, linearly polarized lateral radiation can be formed in the 3.65–4.58 GHz frequency band, and in the 5.70–5.96 GHz frequency band, surface waves can be excited within the metasurface portion 10, resulting in a linearly polarized dual-quasi-end-fire pattern at the edge due to discontinuous diffraction. Furthermore, placing a circularly polarized antenna array 31 operating within the metasurface transparent frequency band below the dipole patch 22 can achieve circularly polarized lateral firing performance in the 19.45–21.85 GHz range. Therefore, this three-band shared metasurface antenna can be simultaneously applied to vehicular terrestrial 5G communication, vehicle-to-everything (V2X) communication, and low-orbit satellite communication, possessing advantages such as heterogeneous frequency and directionality, heterogeneous frequency and polarization, and high structural reuse efficiency.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A three-band shared metasurface antenna, characterized in that, It includes a metasurface portion, a printed dipole portion, and a circularly polarized antenna array portion arranged sequentially from top to bottom, with gaps reserved between the metasurface portion and the printed dipole portion, and between the printed dipole portion and the circularly polarized antenna array portion; The metasurface portion includes a dielectric substrate A and a metasurface unit array, the metasurface unit array being disposed on the dielectric substrate A; each metasurface unit includes two windmill-shaped patches and short-circuit probes, the two windmill-shaped patches being printed on the upper and lower surfaces of the dielectric substrate A respectively; there are multiple short-circuit probes, and the multiple short-circuit probe arrays are distributed to connect the two windmill-shaped patches of the metasurface unit respectively. The printed dipole portion includes a dielectric substrate B and a dipole patch, wherein the dipole patch is printed on the top surface of the dielectric substrate B and has a port E. The circularly polarized antenna array includes a circularly polarized antenna array, a dielectric substrate C, a dielectric substrate D, and a feeding structure. The circularly polarized antenna array is disposed on the dielectric substrate C, the dielectric substrate D is disposed below the dielectric substrate C, and the feeding structure is printed on the bottom surface of the dielectric substrate D and has a port F.

2. The three-band shared metasurface antenna according to claim 1, characterized in that, The metasurface unit array consists of 13×13 metasurface units arranged periodically.

3. The three-band shared metasurface antenna according to claim 1, characterized in that, The relative permittivity of the dielectric substrate A is 3.

5.

4. The three-band shared metasurface antenna according to claim 1, characterized in that, The relative permittivity of the dielectric substrate B is 3.

5.

5. The tri-band shared metasurface antenna according to claim 1, characterized in that, The circularly polarized antenna array consists of 2×2 circularly polarized antennas arranged in a periodic pattern.

6. The three-band shared metasurface antenna according to claim 1, characterized in that, The dielectric substrate C has a relative permittivity of 3.5, and the dielectric substrate D has a relative permittivity of 2.2.

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