Ultra-high isolation large-angle scanning dual-circularly polarized antenna element and array

Abstract

The application discloses a kind of ultra-high isolation large-angle scanning dual circular polarized antenna unit and array, antenna unit includes by sequentially coaxial arrangement feed conversion interface, polarizer, dielectric waveguide, dielectric transition section and super surface layer from bottom to top;Dielectric waveguide is extended along the waveguide cavity in the dielectric matrix in transmission direction, cavity is equipped with double-channel isolation wall for physically separating two polarized signals, feed conversion interface adopts double-way symmetry structure, polarizer is built-in and the separation structure corresponding to isolation wall is connected, dielectric transition section adopts gradually changing refractive index dielectric rod structure, and super surface layer is laid on the radiation end face.The application can effectively block polarization crosstalk, inhibit array mutual coupling by constructing full-link polarization isolation system, and the port isolation is excellent, ±60° can be realized without grating lobe beam scanning, and is suitable for various satellite communication phased array systems.

Description

Technical Field

[0001] This invention relates to the field of microwave antennas and phased array antennas, and more particularly to an ultra-high isolation, large-angle scanning dual circularly polarized antenna element and array. Background Technology

[0002] With the rapid development of low-Earth orbit satellite communication and spaceborne phased array technology, spaceborne and terrestrial satellite communication systems have placed multiple stringent requirements on antenna performance: First, they must simultaneously support left-hand and right-hand circular polarization to meet the polarization diversity communication requirements of satellite uplink transmission and downlink reception; second, the beam must have a large-angle scanning capability to achieve continuous ±60° full-domain tracking of high-speed passing low-Earth orbit satellites; third, the isolation between left-hand and right-hand circular ports within the unit must reach more than 30dB to effectively suppress crosstalk in the transmit and receive channels and ensure the signal-to-noise ratio of full-duplex communication with the same aperture; fourth, the array units must have low electromagnetic coupling characteristics to avoid a significant drop in port isolation performance after arraying; and fifth, the antenna must meet the requirements of small size, lightweight design, and integrated molding to adapt to the limited payload space of satellites and the need for weight reduction in launch vehicles.

[0003] Currently, conventional dual-circularly polarized phased array antennas still have many technical defects, making it difficult to fully meet the requirements of satellite communication. Regarding beam scanning performance, the element apertures of traditional metal waveguide antennas and microstrip patch antennas are generally larger than half the operating wavelength, resulting in excessively large array element spacing. Grating lobes appear when the beam scan reaches approximately ±45°, making it impossible to achieve blind-zone-free satellite tracking over a large angle of ±60°, thus limiting satellite overpass tracking time. In terms of port isolation performance, conventional dual-circularly polarized antennas lack a dedicated polarization isolation structure for the entire link. Significant impedance abrupt changes exist at the interface between the medium and air, and electromagnetic wave reflections at the interface easily cause energy crosstalk between channels. The left and right rotation port isolation is generally less than 20dB, far below the 30dB hard isolation requirement for satellite communication. During common-aperture transmission and reception, the high-power signal from the transmitting channel severely interferes with the receiving channel, directly reducing the communication signal-to-noise ratio. Regarding array performance, the spatial electromagnetic coupling between adjacent radiating elements is further intensified after multi-element arraying, and the port isolation will continue to deteriorate to within 15dB. This can easily cause self-oscillation of the onboard power amplifier and a precipitous drop in receiver sensitivity, making it impossible to guarantee stable operation of full-duplex communication. In terms of structure and power supply adaptation, the TEM wave output from the standard SMP RF feed port is mismatched with the TE / TM wave mode transmitted by the dielectric waveguide, requiring an additional matching network. This increases the size of the onboard antenna and also increases the RF link loss. At the same time, the number of assembly parts for the split waveguide and polarizer is large, and the assembly tolerance is easily amplified in the high and low temperature alternating environment of space, resulting in poor on-orbit reliability and low mass production assembly efficiency.

[0004] In summary, existing technologies generally suffer from drawbacks such as narrow scanning coverage, poor port isolation performance, significant degradation in array performance, bulky structure, and low reliability. The industry has always lacked antenna units and arrays for satellite communication that can simultaneously achieve high isolation, wide-angle scanning, dual circular polarization, low array mutual coupling, and integrated lightweight design. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-high isolation, large-angle scanning dual-circular polarized antenna element and array. By constructing a full-link polarization isolation system, polarization crosstalk can be effectively blocked, array mutual coupling can be suppressed, and port isolation is excellent, thus solving the aforementioned technical problems existing in the prior art. The specific technical solution is as follows: A high-isolation, large-angle scanning dual-circular polarized antenna element includes, from bottom to top, a feed conversion interface, a polarizer, a dielectric waveguide, a dielectric transition section, and a metasurface layer arranged coaxially. The dielectric waveguide includes a dielectric substrate, inside which is a waveguide cavity extending along the electromagnetic wave propagation direction. The waveguide cavity contains a dual-channel isolation wall for physically isolating the propagation paths of left-hand circularly polarized electromagnetic waves and right-hand circularly polarized electromagnetic waves. The feed conversion interface adopts a dual-path symmetrical structure to feed power to the two polarization channels respectively. The polarizer has a built-in separator structure corresponding to the dual-channel isolation wall to physically separate the two orthogonally polarized signals. The radiating end of the dielectric waveguide is provided with a dielectric transition section using a graded refractive index dielectric rod structure to eliminate impedance abrupt changes at the dielectric-air interface and block polarization crosstalk caused by interface reflection. The metasurface layer is laid on the radiating end face to suppress spatial electromagnetic coupling between adjacent elements after arraying.

[0006] Furthermore, the power conversion interface includes an SMP interface, a metal feed pin, and symmetrical metal steps. The SMP interface is connected to the metal feed pin, and the metal feed pin is connected to the symmetrical metal steps. The two sets of symmetrical metal steps are centrally symmetrically distributed and closely attached to the lower surface of the polarizer, which is used to realize the mode conversion from TEM wave to TE wave or TM wave.

[0007] Furthermore, the polarizer is a multi-stage dielectric polarization plate structure, with the separation structure extending along the electromagnetic wave propagation direction to generate a 90° phase difference between the two orthogonal polarization components to synthesize a circularly polarized wave.

[0008] Furthermore, the dielectric substrate is a one-piece injection-molded plastic dielectric substrate, and the waveguide cavity and dual-channel isolation wall are also integrally molded with the dielectric substrate.

[0009] Furthermore, the dielectric transition section is a gradient refractive index dielectric rod integrally extended from the top of the waveguide cavity, and the cross-section of the gradient refractive index dielectric rod narrows smoothly along the radiation direction.

[0010] Furthermore, the metasurface layer employs a periodic square metal patch array, printed on the upper surface of the dielectric transition section.

[0011] Furthermore, the aperture of the antenna element is less than 1 / 2 of the operating wavelength, which is used to achieve ±60° grating-free beam scanning.

[0012] Furthermore, the power conversion interface is compatible with a 50Ω standard impedance.

[0013] Furthermore, the polarizer is a sixth-order dielectric polarizer structure.

[0014] An ultra-high isolation large-angle scanning dual circular polarized antenna array is composed of several ultra-high isolation large-angle scanning dual circular polarized antenna elements arranged in a two-dimensional periodic pattern. The array's radiating surface is entirely covered by a continuous metasurface layer. The array is equipped with a dual-channel independent feeding network to excite the left-hand circular polarized port and the right-hand circular polarized port respectively.

[0015] The ultra-high isolation, large-angle scanning dual circularly polarized antenna element and array of the present invention have the following advantages: 1. By using a coaxial stacked architecture of feed conversion interface, polarizer, dielectric waveguide, dielectric transition section and metasurface layer, combined with the synergistic effect of dual-channel isolation wall, polarizer separation structure, graded dielectric rod and metasurface, a full-link polarization isolation system is constructed from feed, transmission, polarization conversion to radiation end. It not only physically separates the two polarized signals in the transmission path, but also eliminates reflection crosstalk at the impedance matching level, and suppresses spatial mutual coupling after arraying. It effectively solves the core problems of insufficient port isolation of traditional dual circular polarized antennas and performance degradation after arraying, and can stably meet the isolation index requirements of satellite common aperture full-duplex communication.

[0016] 2. The SMP interface, combined with the metal feed pin and symmetrical metal step feed structure, can directly realize the mode conversion from coaxial TEM wave to dielectric waveguide TE / TM wave, while completing the 50Ω standard impedance matching. No additional matching network is required, and it can be directly adapted to general satellite TR components. The dual-channel centrally symmetrical layout allows the two polarization signals to be physically separated from the feed end, reducing polarization crosstalk caused by the feed network from the source and simplifying the design complexity of the system RF link.

[0017] 3. The multi-stage dielectric polarizer structure can form a stable 90° phase difference between two orthogonal polarization components over a wide frequency band, ensuring the axial ratio performance and polarization purity of the circularly polarized signal; the separation structure extending along the transmission direction is connected to the dual-channel isolation wall in the waveguide to ensure that the two signals remain physically isolated during the polarization conversion stage, maintain the continuity of the isolation link, and avoid energy crosstalk in the polarization conversion stage.

[0018] 4. The one-piece injection-molded plastic dielectric substrate allows the waveguide cavity and the dual-channel isolation wall to be molded simultaneously, which greatly reduces the number of parts and assembly steps of the antenna unit, reduces performance fluctuations caused by assembly tolerances, and improves the structural reliability under the alternating high and low temperature environment in space. At the same time, the plastic dielectric substrate is significantly lighter than the traditional metal waveguide, which better meets the lightweight design requirements of spaceborne payloads.

[0019] 5. The gradient refractive index dielectric rod extending integrally from the top of the waveguide cavity has a smooth narrowing cross section along the radiation direction, seamlessly connecting with the waveguide body to avoid performance loss introduced by assembly gaps; the continuously gradient refractive index can achieve a smooth impedance transition from the dielectric to the air, significantly reducing the reflected wave energy at the interface, blocking polarization crosstalk caused by reflection backlash from the root, and widening the antenna's operating bandwidth while improving port isolation.

[0020] 6. The periodic square metal patch array printed on the upper surface of the dielectric transition section serves as a metasurface layer. The fabrication process is simple and the patches are tightly bonded, requiring no additional mounting structure. The periodically arranged metal patches can regulate the surface electromagnetic boundary at the radiating end, suppress the propagation of surface waves between adjacent units, effectively weaken the spatial electromagnetic coupling between array units, alleviate the problem of port isolation deterioration after arraying, and ensure stable isolation performance of the array under full scanning angle. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall layered exploded structure of the ultra-high isolation large-angle scanning dual circularly polarized antenna unit of the present invention.

[0022] Figure 2 This is a top view of the SMP feed pin and symmetrical metal steps of the feed conversion interface in the ultra-high isolation large-angle scanning dual circular polarized antenna unit of the present invention.

[0023] Figure 3 This is a schematic diagram of the cross-section of the multi-stage polarization structure inside the polarizer in the ultra-high isolation large-angle scanning dual circular polarization antenna unit of the present invention.

[0024] Figure 4 This is an axial cross-sectional view of the transition section between the dielectric waveguide and the graded dielectric in the ultra-high isolation large-angle scanning dual circularly polarized antenna unit of the present invention.

[0025] Figure 5 This is a schematic diagram of the periodic structure plane of the top metasurface layer of the ultra-high isolation large-angle scanning dual circularly polarized antenna unit of the present invention.

[0026] Figure 6 This is a schematic diagram of the structure of the ultra-high isolation large-angle scanning dual circularly polarized antenna unit of the present invention.

[0027] Figure 7This is a schematic diagram of the overall layout of the ultra-high isolation large-angle scanning dual circularly polarized antenna array of the present invention.

[0028] Figure 8 This is a return loss curve of the ultra-high isolation large-angle scanning dual circularly polarized antenna element of the present invention.

[0029] Figure 9 This is a port isolation curve of the ultra-high isolation large-angle scanning dual circularly polarized antenna element of the present invention.

[0030] Figure 10 This is a graph showing the normal axis ratio of the dual circularly polarized wave in the ultra-high isolation, large-angle scanning dual circularly polarized antenna element of this invention.

[0031] Figure 11 This is a port isolation curve of the ultra-high isolation large-angle scanning dual circularly polarized antenna array of the present invention. Detailed Implementation

[0032] To better understand the purpose, structure, and function of this invention, the ultra-high isolation large-angle scanning dual circularly polarized antenna element and array of this invention will be described in detail below with reference to the accompanying drawings.

[0033] like Figures 1 to 11 As shown, the ultra-high isolation large-angle scanning dual circular polarization antenna element 100 and array provided by the present invention are suitable for Ku / Ka band satellite communication active phased array systems, and can simultaneously support left-hand and right-hand circular polarization signal transmission and reception, meeting the usage requirements of common aperture full-duplex communication.

[0034] The ultra-high isolation, large-angle scanning dual circularly polarized antenna element 100 adopts a coaxial stacked configuration. From bottom to top, it consists of a feed conversion interface 1, a polarizer 2, a dielectric waveguide 3, a dielectric transition section 4, and a metasurface layer 5. The dielectric waveguide 3 serves as the main structure for electromagnetic wave transmission. It contains a waveguide cavity 32 extending along the transmission direction. Inside the cavity, a dual-channel isolation wall divides the single cavity into two independent polarization transmission channels, corresponding to the transmission paths of left-hand and right-hand circularly polarized signals, respectively. This physically separated structure confines the field distribution of the two polarized signals within their respective channels, preventing energy coupling during transmission and forming the basis of a fully polarization-isolated transmission layer.

[0035] The power conversion interface 1 adopts a dual-path symmetrical structure, serving as the connection between the unit and the external RF link. It mainly includes an SMP interface 11, a metal feed pin 12, and symmetrical metal steps 13. The core of the SMP interface 11 is connected to the metal feed pin 12. After coaxial transmission, the RF signal is guided by the metal feed pin 12 to the symmetrical metal steps 13 above. The two sets of metal steps are symmetrically distributed around the unit axis, with their upper surfaces closely attached to the lower surface of the polarizer 2. This structure can smoothly convert coaxially transmitted TEM mode electromagnetic waves into TE or TM modes that can be transmitted within the dielectric waveguide 3, while achieving 50Ω standard impedance matching and a full-band VSWR ≤1.3. It can directly adapt to general satellite TR components without the need for additional matching network design, effectively simplifying the system RF link design. The dual-path symmetrical layout ensures that the two polarized signals are independent from the feed end, reducing polarization crosstalk caused by the power supply network from the signal source. The metal feed needle 12 and the symmetrical metal steps 13 are both made using anti-corrosion stamping technology, which can withstand the space environment of vacuum and alternating high and low temperatures, and are suitable for the harsh working conditions of spaceborne and airborne applications.

[0036] Polarizer 2 is located at the feed end of waveguide cavity 32 and employs a multi-stage dielectric polarization structure. Internally, it features a partition structure extending along the transmission direction. This partition structure corresponds to and connects with the lower dual-channel isolation wall, ensuring physical isolation between the two signals during polarization conversion. During operation, two orthogonal linearly polarized signals enter the two channels of polarizer 2. Under the influence of the multi-stage dielectric structure, the propagation constants of the two orthogonal polarization components differ, accumulating a 90° phase difference after passing through a predetermined transmission path. This phase difference then synthesizes a left-hand circularly polarized electromagnetic wave and a right-hand circularly polarized electromagnetic wave, respectively. The multi-stage structure design maintains a stable phase difference over a wide frequency band, improves the circular polarization axial ratio performance, and ensures the polarization purity required for satellite communication.

[0037] In this embodiment, the dielectric substrate 31 of the dielectric waveguide 3 is made of aerospace-modified engineering plastic with a dielectric constant of 3.2 through an integrated injection molding process. The waveguide cavity 32 and the dual-channel isolation wall are also manufactured integrally with the dielectric substrate 31. Compared with the traditional scheme of separate preparation and assembly of metal waveguides, the integrated injection molding structure significantly reduces the number of parts and assembly steps, which not only reduces the performance fluctuation caused by assembly tolerances and improves the structural reliability under the high and low temperature alternating environment in space, but also significantly reduces the overall weight of the antenna element 100, adapting to the lightweight design requirements of spaceborne payloads.

[0038] At the radiating end of the dielectric waveguide 3, a dielectric transition section 4 is provided. This transition section is a graded refractive index dielectric rod structure, integrally formed by extending the dielectric from the top of the waveguide cavity 32. Its cross-section narrows smoothly along the radiation direction, and the equivalent refractive index gradually changes with the cross-sectional size. In the conventional dielectric waveguide 3 radiation structure, there is a significant impedance abrupt change at the interface between the dielectric and air, which causes a large number of electromagnetic waves to be reflected at the interface. The reflected energy can easily enter another polarization channel, becoming an important reason for the deterioration of port isolation. The graded refractive index dielectric rod used in this embodiment can achieve a smooth transition from the dielectric impedance inside the waveguide to the free space impedance, greatly weakening the intensity of reflected waves at the interface and blocking polarization crosstalk caused by reflection backlash from the root. It is the core structure for achieving high port isolation of the unit; at the same time, the smooth impedance transition also helps to broaden the operating bandwidth of the unit and improve radiation efficiency.

[0039] The metasurface layer 5 is laid on the radiating end face of the unit, specifically as a periodic square metal patch array printed on the upper surface of the dielectric transition section 4. When the antenna elements 100 are arrayed to form a phased array, the radiation fields of adjacent elements will affect each other through spatial coupling, causing the isolation of the unit ports to drop significantly compared to the isolated state. The metasurface layer 5 set in this embodiment can control the surface electromagnetic boundary of the unit's radiating end through the periodic metal structure, suppress the propagation of surface waves between units, weaken the spatial electromagnetic coupling strength of adjacent units, and reduce the mutual coupling between array units by about 20dB. This alleviates the problem of deterioration in isolation after arraying, ensuring that a high level of polarization isolation can still be maintained in the array state. The performance can be maintained without setting up an additional isolation barrier, effectively reducing the occupied volume of the satellite phased array surface.

[0040] In this embodiment, the overall aperture of the antenna element 100 is less than half the operating wavelength. For phased array antennas, the element spacing is a key parameter determining the beam scanning range and grating lobe characteristics. When the element spacing is controlled within half the wavelength, it can support beam scanning within a large angle range of ±60° without grating lobes. The small-aperture element design allows the array to adopt a more compact arrangement, ensuring continuous tracking capability for low-Earth orbit satellites passing at high elevation angles, effectively extending the satellite-to-ground communication duration, and also helping to reduce the overall physical size of the array.

[0041] As a further optimization, the polarizer 2 in this embodiment adopts a sixth-order dielectric polarizer structure. By refining the design of the size and dielectric properties of each order of dielectric, the stability of the phase difference can be further improved within the target operating frequency band, so that the unit normal axis ratio can be controlled within 1dB, which meets the high requirements of satellite communication systems for circular polarization purity.

[0042] Based on the aforementioned antenna element 100, this invention also provides a corresponding ultra-high isolation, large-angle scanning dual circular polarization antenna array 200. The array is composed of several of the aforementioned antenna elements 100 arranged according to a two-dimensional periodic rule. The overall dielectric substrate 31 of the array can be integrally injection molded, achieving a 40% weight reduction and a 30% reduction in profile height compared to traditional metal waveguide arrays. The overall radiating surface of the array is covered by a continuous metasurface layer 5, further optimizing the mutual coupling suppression effect at the array level. The array is equipped with a dual-channel independent feed network, which feeds and controls the amplitude and phase of the left-hand and right-hand circular polarization ports of all elements respectively, forming an active phased array capable of beam scanning. This array maintains excellent isolation performance between the left and right-hand circular polarization ports across the entire scanning angle range, significantly reducing interference from the transmitting channel to the receiving channel, avoiding self-oscillation problems in the onboard power amplifier, and significantly improving the receiving sensitivity of satellite communication. The single-unit integrated dual circular polarization design eliminates the need for two separate sets of transceiver antennas, further compressing the array size and adapting to the limited installation space of payloads such as CubeSats and microsatellites. It can be directly applied to various scenarios such as spaceborne communication payloads, ground-based portable satellite tracking stations, and airborne satellite communication terminals.

[0043] The fabrication and assembly of the antenna unit 100 and array can be carried out according to the following process: First, the dielectric substrate 31 is prepared by using aerospace-grade modified engineering plastic particles and integrally injection molding through a precision injection mold. Simultaneously, the waveguide cavity 32, dual-channel isolation wall, and gradient refractive index dielectric rod are formed. During the injection molding process, the cavity temperature and holding pressure parameters are controlled to ensure the dimensional accuracy and dielectric uniformity of the dielectric structure. Various metal components and metasurface structures are prepared simultaneously. The metal feed pin 12, symmetrical metal steps 13, and metal separation structures in the polarizer 2 are all processed by precision stamping and the surface is treated with anti-corrosion passivation to withstand the vacuum and high and low temperature alternating shocks in the space environment. The metasurface layer 5 is prepared by photolithography on a flexible dielectric film to form a periodic square metal patch array, ensuring pattern accuracy and bonding flatness.

[0044] Following this, unit assembly is performed. The fabricated metal feed assembly is inserted and positioned from the bottom of the dielectric substrate 31, ensuring that the upper surface of the symmetrical metal step 13 is tightly attached to the lower surface of the polarizer 2, guaranteeing the coaxiality and bonding accuracy of each structure. Then, the metasurface layer 5 is bonded and fixed to the upper surface of the dielectric transition section 4, completing the assembly of a single antenna unit 100. During array assembly, the dielectric substrate 31 of all units can be molded in one go using integral injection molding, depending on the array size. Then, the dual-channel feed network is laid out uniformly, and the metasurface layer 5 is bonded to the entire surface. Finally, the matching SMP interface 11 and RF feed line are welded to complete the fabrication and assembly of the entire phased array antenna. The entire process involves a small number of parts, a simple assembly process, and good structural dimensional consistency, making it suitable for the mass production requirements of satellite payloads.

[0045] The terms “above,” “below,” and “within” as used above include the number itself; the terms “exceeding” and “excluding” do not include the number itself.

[0046] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific descriptions herein should not be construed as limiting the substance and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention. The various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0047] If the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

Claims

1. A dual circularly polarized antenna element with ultra-high isolation and large-angle scanning, characterized in that, The array comprises, from bottom to top, a coaxially arranged feed conversion interface, a polarizer, a dielectric waveguide, a dielectric transition section, and a metasurface layer. The dielectric waveguide includes a dielectric substrate with a waveguide cavity extending along the electromagnetic wave propagation direction. The waveguide cavity contains a dual-channel isolation wall to physically isolate the propagation paths of left-hand circularly polarized electromagnetic waves and right-hand circularly polarized electromagnetic waves. The feed conversion interface employs a dual-path symmetrical structure to feed power to the two polarization channels respectively. The polarizer has a built-in separator structure corresponding to the dual-channel isolation wall to physically separate the two orthogonally polarized signals. The radiating end of the dielectric waveguide has a dielectric transition section with a graded refractive index dielectric rod structure to eliminate impedance abrupt changes at the dielectric-air interface and block polarization crosstalk caused by interface reflection. The metasurface layer is laid on the radiating end face to suppress spatial electromagnetic coupling between adjacent units after arraying.

2. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to claim 1, characterized in that, The power conversion interface includes an SMP interface, a metal feed pin, and symmetrical metal steps. The SMP interface is connected to the metal feed pin, and the metal feed pin is connected to the symmetrical metal steps. The two sets of symmetrical metal steps are centrally symmetrically distributed and closely attached to the lower surface of the polarizer, which is used to realize the mode conversion from TEM wave to TE wave or TM wave.

3. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to claim 1, characterized in that, The polarizer is a multi-stage dielectric polarizer structure. The separation structure extends along the electromagnetic wave transmission direction to generate a 90° phase difference between the two orthogonal polarization components to synthesize a circularly polarized wave.

4. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to claim 1, characterized in that, The dielectric substrate is a one-piece injection molded plastic dielectric substrate, and the waveguide cavity and dual-channel isolation wall are both integrally molded with the dielectric substrate.

5. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to claim 4, characterized in that, The dielectric transition section is a gradient refractive index dielectric rod integrally extended from the top of the waveguide cavity, and the cross-section of the gradient refractive index dielectric rod narrows smoothly along the radiation direction.

6. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to any one of claims 1 to 5, characterized in that, The metasurface layer is a periodic square metal patch array printed on the upper surface of the dielectric transition section.

7. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to any one of claims 1 to 5, characterized in that, The aperture of the antenna element is less than 1 / 2 of the operating wavelength, which is used to achieve ±60° grating-lobe-free beam scanning.

8. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to claim 2, characterized in that, The power conversion interface is compatible with a 50Ω standard impedance.

9. The ultra-high isolation large-angle scanning dual circularly polarized antenna element according to claim 3, characterized in that, The polarizer is a sixth-order dielectric polarizer structure.

10. A high-isolation, large-angle scanning dual-circularly polarized antenna array, characterized in that, It is composed of several ultra-high isolation large-angle scanning dual circularly polarized antenna elements as described in any one of claims 1 to 9, arranged in a two-dimensional periodic manner. The array radiating surface is covered by a continuous metasurface layer. The array is configured with a dual-channel independent feeding network to excite the left-hand circularly polarized port and the right-hand circularly polarized port respectively.

Images