Metasurface, antenna and communication device
By designing the metal layer structure of the metasurface unit and independently controlling the polarization, a full-space Bessel beam is generated, solving the problems of resource waste and OAM divergence angle in traditional metasurfaces, and achieving efficient utilization of communication resources.
Patent Information
- Application Number
- CN202520418838.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-03-11
AI Technical Summary
Traditional metasurfaces use only half-space resources to generate vortex electromagnetic waves, resulting in a waste of space resources, and the divergence angle of OAM limits its application in long-distance communication.
Design a metasurface comprising uniformly arranged metasurface units, with a metal layer consisting of a metal square ring, a single-sided open circular ring, a double-sided open circular ring, and a circular patch. By independently controlling left-handed and right-handed circularly polarized electromagnetic waves, a Bessel beam is generated in the entire space.
It enables the utilization of all space resources, solves the problem of OAM divergence angle, generates diffraction-free Bessel beams, and improves communication capacity and efficiency.
Smart Images
Figure CN223843182U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of communication technology, and in particular to a metasurface, antenna, and communication device. Background Technology
[0002] Orbital angular momentum (OAM), as a new degree of freedom for manipulating electromagnetic waves, has become a research hotspot due to its ability to exponentially increase channel capacity and efficiency. Currently, various schemes exist for generating vortex electromagnetic waves with OAM, such as spiral phase plates, reflector antennas, uniform circular arrays, and metasurfaces, to meet the demands of current wireless communication.
[0003] However, the inherent divergence angle of OAM limits its application in long-distance communication. Higher-order Bessel beams carrying OAM, due to their unique non-diffraction properties, are one solution to this divergence angle problem. Metasurfaces, due to their planar structure, cost-effectiveness, and precise electromagnetic wave modulation capabilities, can be used to generate Bessel beams; however, traditional metasurfaces only use half-space to generate vortex electromagnetic waves in the reflection or transmission direction, resulting in a significant waste of space resources. Utility Model Content
[0004] Therefore, it is necessary to provide a metasurface, antenna, and communication device that can utilize all space resources to generate Bessel waves.
[0005] In a first aspect, in one embodiment, this application provides a metasurface, including a plurality of uniformly arranged metasurface units; each metasurface unit includes a dielectric substrate and a metal layer pressed onto both sides of the dielectric substrate; the metal layer includes a metal square ring, a single-sided open ring, a double-sided open ring, and a circular patch;
[0006] The centers of the single-sided open ring, the double-sided open ring, and the circular patch are the same, and their centers coincide with the geometric center of the metal square ring.
[0007] The inner diameter of the double-sided open ring is larger than the diameter of the circular patch, the outer diameter of the double-sided open ring is smaller than the inner diameter of the single-sided open ring, and the outer diameter of the single-sided open ring is smaller than the inner frame side length of the metal square ring.
[0008] The first opening of the double-sided open ring has the same shape as the second opening of the double-sided open ring, but the opening directions are opposite.
[0009] In one embodiment, the direction of the first opening is parallel to the opening direction of the single-sided opening ring.
[0010] In one embodiment, the opening width of the single-sided open annulus is positively correlated with the opening width of the first opening.
[0011] In one embodiment, the positive correlation is a proportional relationship.
[0012] In one embodiment, the metal layer is made of copper.
[0013] In a second aspect, in one embodiment, this application provides an antenna including a metasurface as described in any embodiment of the first aspect.
[0014] In one embodiment, a feed source is also included, positioned directly above the geometric center of the metasurface.
[0015] In one embodiment, the feed source is used to perpendicularly incident left-hand circularly polarized electromagnetic waves and right-hand circularly polarized electromagnetic waves onto the metasurface.
[0016] In one embodiment, the feed source includes a circularly polarized horn.
[0017] In a second aspect, in one embodiment, this application provides a communication device including an antenna as described in any embodiment of the second aspect.
[0018] The aforementioned metasurface, antenna, and communication device include a metasurface unit comprising a dielectric substrate and metal layers laminated to both sides of the dielectric substrate. The metal layers include a square metal ring, a single-sided open circular ring, a double-sided open circular ring, and a circular patch. The centers of the single-sided open circular ring, the double-sided open circular ring, and the circular patch are identical and coincide with the geometric center of the square metal ring. The inner diameter of the double-sided open circular ring is larger than the diameter of the circular patch, and the outer diameter of the double-sided open circular ring is smaller than the inner diameter of the single-sided open circular ring. The outer diameter of the single-sided open circular ring is smaller than the inner frame side length of the square metal ring. The first opening of the double-sided open circular ring and the second opening of the double-sided open circular ring have the same shape but opposite opening directions. Based on the structure of the aforementioned metasurface, this application can independently control left-handed and right-handed circular polarization and utilize full-space vortex electromagnetic waves to generate diffraction-free Bessel beams. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of a metasurface structure in one embodiment;
[0021] Figure 2 This is a schematic diagram of the three-dimensional structure of a metasurface unit in one embodiment;
[0022] Figure 3This is a schematic diagram of the planar structure of a metasurface unit in one embodiment;
[0023] Figure 4 This is a schematic diagram illustrating the annotations of various parameters of a metasurface unit in one embodiment;
[0024] Figure 5 This is a 3D simulation diagram of metasurface emission of vortex electromagnetic waves in full space, along with electric field phase and amplitude results, in one embodiment.
[0025] Figure 6 This is a schematic diagram of the reflection coefficient (a) and transmission coefficient (a) curves of a metasurface under circularly polarized incident conditions in one embodiment.
[0026] Figure 7 Here are the amplitude characteristics (a) and phase characteristics (b) of the metasurface unit in the reflection direction in one embodiment;
[0027] Figure 8 Here are the amplitude characteristics (a) and phase characteristics (b) of the metasurface unit in the transmission direction in one embodiment. Detailed Implementation
[0028] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.
[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0030] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.
[0031] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.
[0032] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.
[0033] Orbital angular momentum (OAM), as a new degree of freedom for manipulating electromagnetic waves, has become a hot research topic due to its ability to exponentially improve channel capacity and efficiency. In traditional technologies, vortex electromagnetic waves can be generated using helical phase plates, reflector antennas, uniform circular arrays, and metasurfaces to meet the needs of wireless communication.
[0034] Metasurfaces are used to generate Bessel beams due to their planar structure, cost-effectiveness, and precise modulation of electromagnetic waves. However, the inherent divergence angle of OAM limits their practical application in long-distance communication. Higher-order Bessel beams carrying OAM can serve as one solution to the aforementioned technical problems due to their unique diffraction-free properties.
[0035] In existing literature, the paper "YANG Y, ZHU Y, XIE W, BU L, ZANG Y, LIU X. High-efficiency ultrathin metasurfaces with simultaneous control of complete phase, amplitude, and polarization[J]. Optics Express, 2023, 31(2):3134-3142" uses a single-layer transmission plate to achieve independent control of amplitude and phase; however, its total profile height is only 4.6 cm. However, the non-diffraction distance only reaches 37.4. ;
[0036] The literature “WU S, ZHANG Y, CUI X, et al. Generation of dual-polarizationorbital angular momentum vortex beams with reflection-type metasurface[J].Optics Communications, 2024, 553: 130107.” uses a reflective anisotropic metasurface to generate single-beam, multi-beam, and vortex electromagnetic waves of different modes.
[0037] The paper “DING G, CHEN S, LUO XY, et al. Ultrathin Single-Substrate Pancharatnam-Berry Phase Metasurface with High Transmission Efficiency[J].IEEE Transactions on Antennas and Propagation, 2023: 1-1.” uses an ultrathin PB-type transmission metasurface and applies Huygens' principle to extend the bandwidth of vortex electromagnetic waves.
[0038] Based on the above literature, in order to further utilize the new degrees of freedom provided by orbital angular momentum to improve communication capacity, the urgent problem to be solved is the hollowness problem generated by metasurfaces: that is, the energy distribution of Bessel beams generated by traditional metasurfaces is ring-shaped, with zero energy in the central region, forming a "hollow region" in energy distribution. In addition, metasurfaces in traditional technology only use half-space resources to generate reflected or transmitted vortex electromagnetic waves, resulting in a huge waste of space resources.
[0039] To address the aforementioned issues, this application provides a metasurface, antenna, and communication device capable of generating Bessel waves using resources throughout space.
[0040] The metasurface described in this application can be applied to antennas or devices with antennas. Specifically, an antenna or antenna array designed based on any of the metasurfaces provided in this application can be used in a transmitter or receiver. For example, the transmitter or receiver may employ a system based on a reflector antenna or a lens antenna: the transmitter and receiver can be a wireless base station or a relay station; the receiver can be a terminal. For example, the transmitter includes a transmitting signal source, a power amplifier (PA), a feed antenna, and a metasurface antenna array. For instance, a carrier signal is emitted from the transmitting signal source in the transmitter and strikes the electromagnetic metasurface antenna array. Simultaneously, the transmitter calculates the phase information corresponding to the maximum gain of the transmitting and receiving antennas, dynamically adjusts the equivalent circuit impedance of the antenna array elements of the metasurface antenna array according to the calculation results, and then modulates the phase of the incident carrier signal and performs reflection and transmission.
[0041] When the solutions of this application embodiment are applied to wireless access network devices, the wireless access network devices can be base transceiver stations (BTS) in Global System for Mobile Communications (GSM) or Code Division Multiple Access (CDMA) networks, node base stations (NB) in Wideband Code Division Multiple Access (WCDMA), evolved NBs (eNBs or eNodeBs) in Long Term Evolution (LTE), radio controllers in Cloud Radio Access Network (CRAN) scenarios, base stations in 5G mobile communication systems or New Radio (NR) communication systems, base stations in future mobile communication systems, access nodes in WiFi systems, devices that perform base station functions in device-to-device (D2D) communication and machine communication, access network devices in future evolved PLMN networks, or vehicle-to-everything (V2X) devices, etc. The embodiments of this application do not limit the specific technologies and specific device forms used in the wireless access network devices. In the embodiments of this application, the terms 5G and NR can be used interchangeably.
[0042] When the solution of the embodiments of this application is applied to a terminal device, the terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, and so on.
[0043] In one embodiment, such as Figure 1 As shown, this application provides a metasurface 10, comprising a plurality of uniformly arranged metasurface units 100. Please refer to... Figure 2 The metasurface unit 100 includes a dielectric substrate and metal layers laminated to both sides of the dielectric substrate. Please refer to [reference needed]. Figure 3 The metal layer includes a metal square ring 102, a single-sided open circular ring 104, a double-sided open circular ring 106, and a circular patch 108.
[0044] Among them, the single-sided open ring 104, the double-sided open ring 106 and the circular patch 108 have the same center, and the center coincides with the geometric center of the metal square ring 102; the inner diameter of the double-sided open ring 106 is larger than the diameter of the circular patch 108, the outer diameter of the double-sided open ring 106 is smaller than the inner diameter of the single-sided open ring 104, and the outer diameter of the single-sided open ring 104 is smaller than the inner frame side length of the metal square ring 102; the first opening of the double-sided open ring 106 and the second opening of the double-sided open ring 106 have the same shape but opposite opening directions.
[0045] The metal layer formed by the metal square ring 102, the single-sided open circular ring 104, the double-sided open circular ring 106, and the circular patch 108 can extend the bandwidth of the metasurface 10. For example, the single-sided open circular ring 104 and the double-sided open circular ring 106 can be a single-sided open circular resonant ring and a double-sided open circular resonant ring, respectively. Optionally, the dielectric substrate of the metasurface unit 100 can be an F4BM2-2 dielectric substrate, and the thickness of the dielectric substrate can be set according to application requirements.
[0046] In practical applications, such as Figure 1As shown, a feed source 20 can be provided above the metasurface 10. The feed source 20 is used to vertically incident left-hand circularly polarized electromagnetic waves and right-hand circularly polarized electromagnetic waves onto the metasurface 10 so that the metasurface 10 generates the required Bessel beam.
[0047] Specifically, in this embodiment, spin decoupling can be achieved by setting the arrangement of the metal patches of the metasurface unit 100 and the size of the metal layer structure (metal square ring 102, single-sided open circular ring 104, double-sided open circular ring 106 and circular patch 108), thereby realizing independent control of the two spiral circular polarizations of the target Bessel beam generated by the metasurface 10 through spin decoupling.
[0048] Using the aforementioned metasurface 10, vortex electromagnetic waves of mode 1 can be generated in both the reflection and transmission directions. Furthermore, since the metasurface 10 generates a Bessel beam, it can address the OAM divergence angle problem to some extent. In addition, the metasurface 10 of this embodiment can generate beams in both directions, fully utilizing all space resources. It can maintain essentially consistent amplitudes of reflection and transmission (around 0.5) in the 7-10 GHz range and ensure 360° phase coverage, effectively solving the hollow problem that is difficult to handle with traditional metasurfaces 10.
[0049] In one embodiment, the direction of the first opening is parallel to the opening direction of the one-sided opening annulus 104.
[0050] The orientation of the first opening of the double-sided open annulus 106 can affect the geometric phase of the target Bessel wave generated by the metasurface 10.
[0051] Specifically, the opening directions of the first opening, the second opening, and the single-sided opening ring 104 of the double-sided opening ring 106 of the metasurface unit 100 are kept parallel in the same plane, that is, the rotation angle of any of the above openings is the same as the rotation angle of the other openings.
[0052] In one embodiment, the opening width of the single-sided open annular ring 104 is positively correlated with the opening width of the first opening.
[0053] The opening width of the first opening of the double-sided opening ring 106 and the opening width of the single-sided opening ring 104 can affect the propagation phase of the target Bessel wave generated by the metasurface 10.
[0054] In one embodiment, the positive correlation is a proportional relationship.
[0055] For example, the ratio between the opening width of the first opening of the double-sided opening ring 106 and the opening width of the single-sided opening ring 104 can be 1.2.
[0056] It is understood that the ratio between the opening width of the first opening of the double-sided opening ring 106 and the opening width of the single-sided opening ring 104 is not limited to the implementation methods mentioned in the above embodiments. The embodiments of this application do not specifically limit the ratio between the opening width of the first opening of the double-sided opening ring 106 and the opening width of the single-sided opening ring 104.
[0057] In one embodiment, the metal layer is made of copper.
[0058] To make the technical solutions and structures of the embodiments of this application clearer, as follows: Figure 4 The annotations for the various parameters of the metasurface unit 100 shown herein illustrate an exemplary structure of the metal layer of the metasurface unit 100, which will be further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0059] In one possible implementation, please refer to Figure 4 As shown in Table 1, the key parameters of the 100 metal layer of the metasurface unit are as follows:
[0060] Table 1
[0061]
[0062] Where p is the width of the metasurface unit 100, h is the thickness of the metasurface unit 100 (not shown in the figure), r1 is the radius of the circular patch 108, r2 is the outer diameter of the double-sided opening ring 106, r3 is the inner diameter of the single-sided opening ring 104, r4 is the outer diameter of the single-sided opening ring 104, r5 is the inner diameter of the double-sided opening ring 104, x1 is the depth of the opening (including the first and second openings) of the double-sided opening ring 106, x2 is the depth of the opening of the single-sided opening ring 104, y1 is the opening width of the second opening of the double-sided opening ring 106 (numerically the same as the opening width of the first opening), y2 is the opening width of the single-sided opening ring 104, and t is the frame width of the metal frame 102. Furthermore, Figure 4 The opening direction (i.e., rotation angle α) of the first opening of the double-sided open annular ring 106 shown is 90°.
[0063] Based on the metasurface 10 structure of the aforementioned metasurface unit 100, left-handed and right-handed circularly polarized electromagnetic waves can be vertically incident above the metasurface 10 using the feed 20, thus obtaining, for example, Figure 5 The image shows a 3D simulation of the full-space vortex electromagnetic wave emitted by the metasurface 10 structure, as well as the electric field phase and amplitude results of the Bessel beam.
[0064] Furthermore, based on the metasurface 10 structure of the aforementioned metasurface unit 100, it is also possible to obtain, for example... Figure 6 The reflection coefficient of the metasurface 10 shown under circularly polarized incident conditions ( Figure 6 a) and transmission coefficient ( Figure 6 b). Optionally, the feed source 20 may be a circularly polarized horn.
[0065] In some examples, such as Figure 7 and Figure 8 As shown, based on the metasurface structure of the aforementioned metasurface unit 100, and according to the opening direction (i.e., rotation angle α) of the first opening of the double-sided open annulus 106, the reflection of the metasurface unit 100 can also be obtained. Figure 7 a) Amplitude characteristics and ( Figure 7 b) Phase characteristics, and the transmission of the metasurface unit 100 can be obtained ( Figure 8 a) Amplitude characteristics and ( Figure 8 b) Phase characteristics.
[0066] In one embodiment, the opening direction of the first opening of each metasurface unit can be determined based on the circular polarization phase of the target Bessel beam in the full space of the metasurface, specifically including:
[0067] Based on the rotation angle function relationships shown in Formulas 1 to 3 below, the direction of the first opening of each metasurface unit on the metasurface is obtained:
[0068] (Formula 1)
[0069] (Formula 2)
[0070] (Formula 3)
[0071] in, The right-hand circularly polarized phase of the target Bessel beam. The left-hand circularly polarized phase of the target Bessel beam. It is the linear polarization phase difference of the target Bessel beam. θ is the rotation angle of the first opening of the metasurface unit.
[0072] Specifically, the opening direction (i.e., rotation angle α) of the first opening of each metasurface unit can be determined based on the right-hand circular polarization phase and the left-hand circular polarization phase of the desired target Bessel beam. Based on the above-mentioned metasurface unit structure and orientation settings, this embodiment utilizes circular polarization spin decoupling to achieve independent control of the two circular polarization directions.
[0073] In some examples, when the opening directions of the first opening, the second opening, and the single-sided opening of the metasurface unit's double-sided opening annulus are kept parallel in the same plane, the rotation angles of the openings of the first opening, the second opening, and the single-sided opening annulus are all the same; for example, such as Figure 4 As shown, at this time, the rotation angle α of the first opening of the double-sided open ring is 90°, and the opening directions of the second opening and the single-sided open ring are parallel to the first opening.
[0074] In one embodiment, the opening width of the first opening of each metasurface unit on the metasurface can be determined based on the compensation phase, specifically including:
[0075] The compensation phase is obtained using the compensation phase functions described in Formulas 4 to 7 below:
[0076] (Formula 4)
[0077] (Formula 5)
[0078] (Formula 6)
[0079] (Formula 7)
[0080] in, It is the phase compensation required to convert a spherical wave into a plane wave. It is the phase that needs to be compensated for when deflecting the beam. It is the phase required to generate a Bessel beam. It is the wave vector in free space. It is the distance between the geometric center of the metasurface and the feed source. It is the z-axis coordinate of the feed source. It is the elevation angle of the beam deflected on the metasurface. It is the azimuth angle of the deflected beam. It is the convergence angle of the Bessel beam. It is a mode of vortex beam. These are the coordinate values of each metasurface unit. It is the wavelength of free space. It is the wavelength of the operating frequency. and These are the positioning indices for each metasurface unit. It is a compensation phase.
[0081] Based on the compensation phase obtained above, the width of the first opening of each metasurface unit can be scanned and optimized using simulation software, and the opening width of the first opening of each metasurface unit can be selected.
[0082] In one embodiment, this application provides an antenna including a metasurface as described in any of the foregoing embodiments.
[0083] In one embodiment, a feed source is also included, positioned directly above the geometric center of the metasurface.
[0084] For example, the feed source can be used to perpendicularly incident left-hand circularly polarized electromagnetic waves and right-hand circularly polarized electromagnetic waves onto the metasurface. Optionally, the feed source includes a circularly polarized horn. The above antenna structure is simple, without a complex feeding structure, and can be fabricated using PCB technology. Furthermore, it can be applied to multiple frequency bands, offering good economic viability.
[0085] In one embodiment, this application provides a communication device including an antenna as described in any of the above embodiments.
[0086] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.
[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0088] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A metasurface, characterized in that, It includes multiple metasurface units arranged uniformly; each metasurface unit includes a dielectric substrate and metal layers pressed onto both sides of the dielectric substrate; the metal layers include metal square rings, single-sided open circular rings, double-sided open circular rings, and circular patches; The single-sided open annulus, the double-sided open annulus, and the circular patch have the same center, and the center of the circle coincides with the geometric center of the metal square ring. The inner diameter of the double-sided open ring is larger than the diameter of the circular patch, the outer diameter of the double-sided open ring is smaller than the inner diameter of the single-sided open ring, and the outer diameter of the single-sided open ring is smaller than the inner frame side length of the metal square ring. The first opening of the double-sided open ring has the same shape as the second opening of the double-sided open ring, but the opening directions are opposite.
2. The metasurface according to claim 1, characterized in that, The direction of the first opening is parallel to the opening direction of the single-sided opening ring.
3. The metasurface according to claim 1, characterized in that, The opening width of the single-sided open annulus is positively correlated with the opening width of the first opening.
4. The metasurface according to claim 3, characterized in that, The positive correlation is a direct proportional relationship.
5. The metasurface according to any one of claims 1 to 4, characterized in that, The metal layer uses copper as its metal material.
6. An antenna, characterized in that, Including the metasurface as described in any one of claims 1 to 5.
7. The antenna according to claim 6, characterized in that, It also includes a feed source positioned directly above the geometric center of the metasurface.
8. The antenna according to claim 7, characterized in that, The feed source is used to perpendicularly incident left-hand circularly polarized electromagnetic waves and right-hand circularly polarized electromagnetic waves onto the metasurface.
9. The antenna according to claim 7 or claim 8, characterized in that, The feed source includes a circularly polarized horn.
10. A communication device, characterized in that, Including the antenna as described in any one of claims 6 to 9.