Broadband dual-circular-polarization low-cost phased-array antenna array element

Abstract

The invention discloses a broadband dual-circularly-polarized low-cost phased-array antenna array element, which comprises an antenna radiation structure and a slot feed structure which are arranged independently from each other, and is characterized in that the antenna radiation structure comprises a parasitic radiation layer, a first dielectric substrate, an excitation radiation layer and a second dielectric substrate which are arranged in a laminated manner; the slot feed structure comprises a slot layer, a third dielectric substrate, a strip-shaped transmission line and a fourth dielectric substrate; the antenna layer structure and the slot feed structure realize electromagnetic coupling transmission through the slot layer; a hollow symmetrical structure is arranged in the middle of the first dielectric substrate, and the hollow part is used as an air medium to reduce dielectric loss; the gap layer is provided with a multidirectional coupling gap structure; the strip-shaped transmission line is provided with at least two feed ports, and dual circularly polarized radiation is formed in the antenna layer structure through excitation of different feed ports. The antenna radiation layer has no metal through hole or blind hole, can be processed in a layered manner, has the advantages of low processing cost and high yield, and ensures impedance bandwidth while realizing dual circular polarization.

Description

Technical Field

[0001] This invention relates to the field of microwave antenna technology, and more specifically to a broadband dual-circular polarization low-cost phased array antenna element. Background Technology

[0002] Phased array antenna technology is widely used in airborne, missile-borne, and spaceborne communications. With the rapid development of communication technology, people have put forward more requirements for antennas at the front end of the system. Traditional phased array antennas are mostly tile-type modular structures with large size and heavy weight. Microstrip antennas, due to their advantages of small size, light weight, and low profile, are increasingly used in broadband, highly integrated high-frequency broadband communication systems.

[0003] Existing conventional microstrip antennas have narrow bandwidths, making it difficult to achieve broadband and dual circular polarization performance, and their structures are complex. A complete phased array antenna consists of an array surface composed of array elements, an RF link layer, a digital circuit layer, and a beamforming chip. When using bridge feeding, the coaxial signal lines connecting different layers of the antenna need to be connected from the chip end to the excitation and radiation layer. This involves numerous pressing steps during fabrication, difficult blind and buried via fabrication, and a complex feeding structure design, resulting in high fabrication complexity and low processing efficiency for patch antennas, as well as high time and economic costs. If ordinary slot feeding is used, its radiation efficiency is low, and the antenna's low-frequency and high-frequency performance differs significantly, making it difficult to achieve stable broadband antenna performance.

[0004] Therefore, it is necessary to propose a broadband dual-circular polarization low-cost phased array antenna element, which can solve the problems of high cost and low yield caused by the complex stacked structure and difficult blind hole processing of phased array antennas, as well as unstable polarization performance in a wide bandwidth environment. Summary of the Invention

[0005] In view of this, the present invention provides a broadband dual-circular polarization low-cost phased array antenna element to solve the technical problems of excessive number of microstrip dual-circular polarization processing layers, low processing efficiency, complex feeding structure, and unstable broadband performance in the prior art.

[0006] This invention provides a broadband dual-circular polarization low-cost phased array antenna element, comprising, from top to bottom, a parasitic radiating layer, a first dielectric substrate, an excitation radiating layer, a second dielectric substrate, a slot layer, a third dielectric substrate, a strip transmission line, and a fourth dielectric substrate; wherein, the parasitic radiating layer, the first dielectric substrate, the excitation radiating layer, and the second dielectric substrate constitute an antenna radiating layer structure; and the slot layer, the third dielectric substrate, the strip transmission line, and the fourth dielectric substrate constitute a slot feeding structure. The antenna radiating layer structure and the slot feeding structure are structurally independent and do not form an electrical connection. The electromagnetic coupling transfer of energy is achieved through the slot layer. The first dielectric substrate has a hollowed-out symmetrical structure in the middle, and the hollowed-out part serves as an air medium to reduce the energy loss of the antenna. The gap layer is provided with a multi-directional coupling gap structure, which includes multiple gap grooves that are arranged intersecting at the central origin, and the gap grooves are symmetrically distributed along the circumferential direction. The slot layer serves as the upper reference ground of the strip transmission line, and the upper surface of the fourth dielectric substrate serves as the lower reference ground of the strip transmission line, with the lower surface of the fourth substrate being a metal ground plane. The strip transmission line is provided with at least two feed ports, through which circularly polarized radiation with corresponding rotation directions is excited in the antenna radiating layer structure through different feed ports.

[0007] Furthermore, both the parasitic radiation layer and the excitation radiation layer are formed on the surface of the flexible film by etching metal patches; the flexible carrier film is fixed to the first dielectric substrate and the second dielectric substrate by bonding.

[0008] Furthermore, the strip transmission line is an arc-shaped strip line; Both ports at the ends of the arc-shaped strip line are input ports. When the radio frequency signal is input from the first port of the arc-shaped strip transmission line, the energy is uniformly coupled to the excitation radiation layer through the slot layer to form circular polarization. When the radio frequency signal is input from the second port, circular polarization in another direction is formed. By switching the input ports, the left and right circular polarization can be switched.

[0009] Furthermore, the arc angle of the arc-shaped strip is 270°, and the length is 1 / 4λ, where λ is the wavelength corresponding to the working center frequency of the phased array antenna element.

[0010] Furthermore, the slotted layer has a star-shaped structure, consisting of four slots intersecting at the origin; wherein, two equilateral cross-shaped slots have a first length, and two oblique slots have a second length, the first length being greater than the second length, and the second length being the same as the diameter of the arc-shaped strip; the angle between the oblique slots and the equilateral cross-shaped slots is 45°.

[0011] Furthermore, the slot feeding structure includes multiple metal pillars evenly distributed along the four sides of the slot feeding structure. Each metal pillar extends from the lower surface of the fourth dielectric substrate to the slot layer. The structure composed of the multiple metal pillars together with the third dielectric substrate forms a feeding resonant cavity. The resonant frequency of the antenna array element can be adjusted by adjusting the size of each metal pillar and the spacing between adjacent metal pillars.

[0012] Furthermore, the cutout portion of the first dielectric substrate is any one of a rectangle, hexagon, and circle; the dielectric portion surrounding the cutout portion serves as a support portion for the air medium.

[0013] Furthermore, when the cutout portion of the first dielectric substrate is rectangular, the first dielectric substrate has a U-shaped structure, and the frame portion of the U-shaped structure is a dielectric substrate with a dielectric constant of 2-4 to support the parasitic radiation layer.

[0014] Furthermore, both the metal patch in the parasitic radiation layer and the metal patch in the excitation radiation layer have symmetrical geometric structures, and their dimensions are smaller than or equal to the dimensions of the air cavity in the first dielectric substrate.

[0015] Secondly, the present invention also provides a phased array antenna array, comprising a plurality of phased array antenna elements as described in the above technical solutions, wherein the plurality of antenna elements are arranged in a predetermined direction to form an array structure.

[0016] Compared with existing technologies, the broadband dual-circular polarization low-cost phased array antenna element proposed in this invention has the following advantages: 1. By adopting a modular design that separates the radiating structure from the power supply structure, blind metal vias within the radiating layer are eliminated, reducing the overall number of lamination layers. The decoupled processing mode avoids the challenging drilling and electroplating process, significantly reducing the overall board scrap rate caused by localized processing errors. 2. An air cavity structure was introduced into the first dielectric substrate. By utilizing the low loss characteristics of air, the radiation efficiency of high-frequency signals was effectively improved. Combined with the coupling design of parasitic and excitation double-layer radiating patches, the working bandwidth and axial ratio bandwidth of the antenna were broadened through the coordinated work of multiple resonant points, thereby improving the stability of electromagnetic performance in a wide frequency band. 3. Utilizing a unique strip transmission line and a slot layer with a multi-directional coupling slot structure, rapid switching between left- and right-hand circular polarization can be achieved by switching signals at the input port of the strip transmission line, with high polarization purity. Simultaneously, the surrounding metal pillar structure not only improves the electromagnetic isolation between array elements and reduces mutual coupling effects in large-scale arrays, but also provides flexible adjustment methods for impedance matching.

[0017] In summary, the antenna radiating layer of this invention has no metal through-holes or blind holes and can be processed in layers. This new processing technology allows for more flexible processing of the radiating layer, reducing the number of processing layers, improving yield, and lowering manufacturing costs. The innovative use of a multi-directional coupling slot structure layer can ensure impedance bandwidth while achieving dual circular polarization, resulting in more stable antenna performance over a wider bandwidth compared to traditional slot feeding methods. Attached Figure Description

[0018] Figure 1 A schematic diagram of the layered structure of a broadband dual-circular polarization low-cost phased array antenna element provided by the present invention; Figure 2 A perspective structural diagram of the antenna radiating layer provided by the present invention; Figure 3 A current path diagram on an arc-shaped strip provided by the present invention; Figure 4 A perspective view of the slot feed layer provided by the present invention; Figure 5 The antenna port S11 diagram of the antenna array element in the Ka band provided by the present invention; Figure 6 A schematic diagram of the antenna port axial ratio of the antenna array element in the Ka band provided by the present invention; Figure 7 The polarization gain pattern of the antenna array element in the Ka band provided by this invention at the antenna center frequency. Figure 8 A schematic diagram of the phased array antenna array provided by this invention; In the figure, 1-parasitic radiation layer, 2-excitation radiation layer, 3-slot layer, 4-strip transmission line, 5-metal pillar, 6-metal ground plane, 7-first dielectric substrate, 8-second dielectric substrate, 9-third dielectric substrate, 10-upper surface of fourth dielectric substrate, 11-first metal patch, 12-second metal patch, 13-U-shaped frame, 14-overlapping area; 15-arc strip line, 16-rice-shaped slot, 17-first port, 18-second port. Detailed Implementation

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0020] Please see Figure 1 This embodiment provides a broadband dual-circular polarization low-cost phased array antenna element, comprising, from top to bottom, a parasitic radiation layer 1, a first dielectric substrate 7, an excitation radiation layer 2, a second dielectric substrate 8, a slot layer 3, a third dielectric substrate 9, a strip transmission line 4, and a fourth dielectric substrate 10 stacked sequentially; wherein, the parasitic radiation layer 1, the first dielectric substrate 7, the excitation radiation layer 2, and the second dielectric substrate 8 constitute an antenna radiation layer structure; the slot layer 3, the third dielectric substrate 9, the strip transmission line 4, and the fourth dielectric substrate 10 constitute a slot feeding structure; The antenna radiating layer structure and the slot feeding structure are structurally independent and do not form an electrical connection. The electromagnetic coupling transfer of energy is achieved through the slot layer 3. The first dielectric substrate 7 has a hollowed-out symmetrical structure in the middle, and the hollowed-out part serves as an air medium to reduce the energy loss of the antenna. The slot layer 3 is provided with a multi-directional coupling slot structure, which includes multiple slot grooves arranged intersecting at the central origin, and the slot grooves are symmetrically distributed along the circumferential direction; the second dielectric substrate 8 serves as the dielectric layer that couples the slot layer 3 to the excitation radiation layer 2. The slot layer 3 serves as the upper reference ground of the strip transmission line 4, and the upper surface of the fourth dielectric substrate 10 serves as the lower reference ground of the strip transmission line 4. The lower surface of the fourth substrate 10 is a metal ground plane 6. The strip transmission line 4 is provided with at least two feed ports, and circularly polarized radiation with corresponding rotation directions is excited in the antenna radiating layer structure through different feed ports.

[0021] The broadband dual-circular polarization low-cost phased array antenna element provided in this embodiment has several advantages. First, the antenna radiating layer structure and the slot feeding structure are structurally independent and do not form an electrical connection. Electromagnetic coupling transfer of energy is achieved through the slot layer. This non-contact feeding characteristic avoids the parasitic inductance problem of traditional probe feeding and simplifies the manufacturing process. Second, the parasitic radiating layer adds a resonant point to the antenna based on the excitation radiating layer. When the resonant points of the parasitic radiating layer and the excitation radiating layer have different but similar frequencies, the bandwidth can be broadened. Third, the multi-directional coupling slot structure on the slot layer makes it easier to achieve input impedance matching, thereby expanding the bandwidth and overcoming the problems of high cross-polarization and narrow bandwidth of single slots or simple cross slots. Finally, dual circular polarization is achieved through multi-port feeding via a stripline transmission line. Circular polarization rotation switching can be achieved simply by switching ports, simplifying the system control logic and making it suitable for rapid polarization reconfiguration of phased arrays.

[0022] In a preferred embodiment, both the parasitic radiation layer 1 and the excitation radiation layer 2 are formed on the surface of the flexible film by etching metal patches; the flexible carrier film is fixed to the first dielectric substrate 7 and the second dielectric substrate 8 by bonding.

[0023] Specifically, the antenna radiating layer structure in this antenna array element is configured with a separate four-layer structure, including two dielectric substrates (first dielectric substrate 7 and second dielectric substrate 8) and two radiating layers (parasitic radiating layer 1 and excitation radiating layer 2). The two radiating layers have metal patches etched onto a flexible film. Each layer can be processed independently. Both radiating layers are formed by etching metal patches onto a flexible film. There are no metal vias or blind vias throughout the process, which greatly reduces the number of PCB processing layers (at least 4 layers) and lamination times. This flexible processing method significantly reduces process complexity and scrap rate, and greatly saves manufacturing costs.

[0024] It's important to further explain that in traditional rigid PCB multilayer board designs, signal transmission between different layers (e.g., from a bottom-layer chip to a top-layer radiating patch) requires vertical connections via metallized vias or blind / buried vias. However, in this structure, the metal patches for the parasitic radiating layer and the excitation radiating layer are etched onto a flexible film and stacked as independent layers on the dielectric substrate. This eliminates the need for drilling holes within the radiating layer. Therefore, the radiating layer and the power supply structure do not need to be integrally formed, allowing for more flexible fabrication of the radiating layer, reducing the number of layers, improving yield, and lowering manufacturing costs.

[0025] As a specific embodiment, the metal patches in the parasitic radiation layer 1 and the excitation radiation layer 2 are regular squares, or other forms of symmetrical structures. All metal patches are smaller than the size of the air cavity in the first dielectric substrate 7. By employing a separable array element structure, the total number of layers processed on the integrated phased array antenna board is reduced.

[0026] In a preferred embodiment, the cutout portion of the first dielectric substrate 7 is any one of a rectangle, hexagon, and circle; the surrounding dielectric portion of the cutout portion serves as a support portion for the air dielectric.

[0027] In a preferred embodiment, when the cutout portion of the first dielectric substrate 7 is rectangular, the first dielectric substrate 7 has a U-shaped structure, and the frame portion of the U-shaped structure is a dielectric substrate with a dielectric constant of 2-4 to support the parasitic radiation layer.

[0028] To more intuitively demonstrate the structure of the overall antenna radiating layer when the first dielectric substrate has a U-shaped structure, please refer to Figure 2. Figure 2 A top-view structural diagram of the antenna radiating layer is shown. Figure 2 In the parasitic radiation layer 1, the metal patch is a first metal patch 11, and the metal patch in the excitation radiation layer 2 is a second metal patch 12. The size of the first metal patch 11 and the second metal patch 12 can be different, thus making their resonant frequencies different. When their resonant frequencies are in the same frequency band but not the same frequency point, the bandwidth can be broadened. The first dielectric substrate 7 includes a U-shaped frame 13. The U-shaped frame part is a dielectric substrate with a dielectric constant of 3.5, supporting the parasitic radiation layer. The part of the second dielectric substrate 8 within the U-shaped frame is an overlapping area 14. The outer side lengths of the first dielectric substrate 7 and the second dielectric substrate 8 are the same.

[0029] In some embodiments, the size of the two radiating layer metal patches shall not be greater than the size of the air cavity in the first dielectric substrate 7, and the difference in their side lengths shall be greater than 0.4 mm.

[0030] In some embodiments, except for the air portion, the other dielectric substrates are microwave materials with a dielectric constant between 2 and 4 and a loss tangent value of less than 0.0036.

[0031] In a preferred embodiment, the strip transmission line 4 is an arc-shaped strip line; Both ends of the arc-shaped strip line are input ports. When a radio frequency signal is input from either port of the strip transmission line 4, energy is uniformly coupled to the excitation radiation layer 2 through the slot layer 3, forming circular polarization. When a radio frequency signal is input from the other port of the strip transmission line 4, circular polarization in another direction is formed. By switching the input ports, left and right circular polarization switching can be achieved.

[0032] Furthermore, the arc angle of the arc-shaped strip is 270°, its width is determined based on a transmission impedance of 50Ω, and its length is a transmission line of 1 / 4λ, where λ is the wavelength corresponding to the working center frequency of the phased array antenna element.

[0033] like Figure 3 As shown, Figure 3 The current distribution on the arc-shaped stripline is such that when fed at the first port 17, the energy is concentrated at 3 / 4 of the length from the first port 17, and then coupled through a slot, where the energy is concentrated diagonally and coupled to the antenna radiating layer, forming a circular polarization with a spiral direction. When fed at the second port 18, the energy is concentrated at 3 / 4 of the length from the second port 18, and then coupled through a slot layer 3, where the energy is concentrated diagonally and coupled to the radiating layer, forming another circular polarization with a spiral direction.

[0034] In a preferred embodiment, the gap layer 3 has a star-shaped structure, which is formed by four gaps intersecting at the origin; wherein, two equilateral cross-shaped gaps have a first length, and two oblique gaps have a second length, the first length is greater than the second length, and the second length is the same as the diameter of the arc-shaped strip; the angle between the oblique gaps and the equilateral cross-shaped gaps is 45°.

[0035] According to transmission line theory, the electromagnetic energy of the power supply network is first transmitted to the ground plane of the cross-shaped slot layer through the arc-shaped microstrip line. The cross-shaped slot is equivalent to a combination of multiple sets of slot lines. The energy penetrates the ground plane of the slot layer through the slot line coupling, and then couples to the upper excitation radiation layer, and then continues to couple to the parasitic radiation layer, and finally radiates into space.

[0036] Therefore, the advantages of this slot feeding method are that its non-contact feeding characteristic avoids the parasitic inductance problem of traditional probe feeding and simplifies the manufacturing process. Furthermore, by adjusting the length and width of the star-shaped slot, input impedance matching can be achieved, expanding the bandwidth. It also overcomes the problems of high cross-polarization and narrow bandwidth associated with single slots or simple cross-shaped slots. Through the star-shaped slot coupling feeding method, circular polarization can be achieved by feeding through only one port, and its bandwidth and axial ratio performance are excellent.

[0037] As a specific embodiment, a schematic diagram of the slot feed structure consisting of a slot layer, a third dielectric substrate, a strip transmission line, and a fourth dielectric substrate is shown below. Figure 4 As shown, radiated energy is transferred to the metal ground plane of the star-shaped slot layer through the arc-shaped strip line 15, and then coupled to the antenna radiating layer structure through the star-shaped slot 16. The multiple metal pillars 5 are evenly distributed along the edge of the ring slot feeding structure. The lower end of each metal pillar 5 contacts the metal ground plane through the fourth dielectric substrate, and the upper end contacts the star-shaped slot 16.

[0038] It should be noted that in the star-shaped slit 16, the length of the short slit is equivalent to the diameter of the arc-shaped strip 15. With this design, only one port of the arc-shaped strip 15 needs to be powered to achieve circular polarization, and switching ports can achieve dual circular polarization switching function.

[0039] The impedance matching of the feed layer can be adjusted by changing the thickness and spacing of the multiple metal pillars 5 surrounding the edge. This design not only improves the electromagnetic isolation between array elements and reduces the mutual coupling effect when arraying on a large scale, but also provides a flexible means of adjusting the impedance matching.

[0040] As a specific embodiment, the slot-fed structure can be integrated with the RF links and digital circuits below the phased array antenna board as a single unit. During array assembly, it is fixed to the antenna layer as a single board via mounting holes.

[0041] The antenna array element provided in this invention allows for separate processing of each layer of the antenna radiating layer, avoiding the presence of metal vias or buried vias in the radiating layer. The feed layer employs an arc-shaped stripline coupled with a star-shaped slot, and metal pillars are loaded around the feed layer. This structure broadens the antenna bandwidth and significantly improves its circular polarization performance. It reduces the number of processing layers by at least four, reducing processing complexity, scrap rate, and manufacturing costs. Therefore, it achieves the technical effect of reducing manufacturing costs and improving broadband dual circular polarization through a simple feed structure and efficient separation processing method, flexibly processing the radiating layer, reducing the number of processing layers, improving yield, and ultimately achieving both reduced manufacturing costs and improved wideband dual circular polarization.

[0042] The following is combined with Figure 5-7 The actual application effect of this antenna array element is demonstrated. Figure 5The S11 curve of one polarization port of a broadband dual-circular polarization low-cost phased array antenna element in the Ka band is shown. Its impedance operating bandwidth is 25GHz~34GHz, achieving an impedance bandwidth of approximately 30.5%. Figure 6 The figure shows the axial ratio curve of one polarization port of this antenna element when it operates in the Ka band. As can be seen from the figure, its impedance operating bandwidth is 25GHz~32.7GHz, and the axial ratio bandwidth is approximately 26.7%. Figure 7 When the antenna array element operates in the Ka band, the polarization gain of one of the polarization center frequencies, 29.25 GHz, is shown in the figure. As can be seen from the figure, the polarization gain of the array element is above 3.5 dBi.

[0043] This invention also provides a phased array antenna array, including a plurality of phased array antenna elements as described in any of the above technical solutions, wherein the plurality of antenna elements are arranged in a predetermined direction to form an array structure.

[0044] like Figure 8 As shown, Figure 8 This is a schematic diagram of an 8×8 phased array antenna array composed of the phased array antenna elements, which is a typical application of the array elements of the present invention. In this array, individual array elements are rotated sequentially to form a 2×2 array, and then expanded from a 2×2 array to an 8×8 array.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A broadband dual-circular polarization low-cost phased array antenna element, characterized in that, The antenna comprises, from top to bottom, a parasitic radiation layer, a first dielectric substrate, an excitation radiation layer, a second dielectric substrate, a slot layer, a third dielectric substrate, a strip transmission line, and a fourth dielectric substrate, stacked sequentially. The parasitic radiation layer, the first dielectric substrate, the excitation radiation layer, and the second dielectric substrate constitute an antenna radiation layer structure. The slot layer, the third dielectric substrate, the strip transmission line, and the fourth dielectric substrate constitute a slot feeding structure. The antenna radiating layer structure and the slot feeding structure are structurally independent and do not form an electrical connection. The electromagnetic coupling transfer of energy is achieved through the slot layer. The first dielectric substrate has a hollowed-out symmetrical structure in the middle, and the hollowed-out part serves as an air medium to reduce the energy loss of the antenna. The gap layer is provided with a multi-directional coupling gap structure, which includes multiple gap grooves that are arranged intersecting at the central origin, and the gap grooves are symmetrically distributed along the circumferential direction. The slot layer serves as the upper reference ground of the strip transmission line, and the upper surface of the fourth dielectric substrate serves as the lower reference ground of the strip transmission line, with the lower surface of the fourth substrate being a metal ground plane. The strip transmission line is provided with at least two feed ports, through which circularly polarized radiation with corresponding rotation directions is excited in the antenna radiating layer structure through different feed ports.

2. The broadband dual-circular polarization low-cost phased array antenna element according to claim 1, characterized in that, Both the parasitic radiation layer and the excitation radiation layer are formed on the surface of the flexible film by etching metal patches; the flexible carrier film is fixed to the first dielectric substrate and the second dielectric substrate by bonding.

3. The broadband dual-circular polarization low-cost phased array antenna element according to claim 1, characterized in that, The strip transmission line is an arc-shaped strip line; Both ports at the ends of the arc-shaped strip line are input ports. When the radio frequency signal is input from the first port of the arc-shaped strip transmission line, the energy is uniformly coupled to the excitation radiation layer through the slot layer to form circular polarization. When the radio frequency signal is input from the second port, circular polarization in another direction is formed. By switching the input ports, the left and right circular polarization can be switched.

4. The broadband dual-circular polarization low-cost phased array antenna element according to claim 3, characterized in that, The arc angle of the arc-shaped strip is 270°, and the length is 1 / 4λ, where λ is the wavelength corresponding to the working center frequency of the phased array antenna element.

5. The broadband dual-circular polarization low-cost phased array antenna element according to claim 3 or 4, characterized in that, The slotted layer has a star-shaped structure, consisting of four slots intersecting at the origin; two of the cross-shaped slots have a first length, and two of the diagonal slots have a second length. The first length is greater than the second length, and the second length is the same as the diameter of the arc-shaped strip; the angle between the diagonal slots and the cross-shaped slots is 45°.

6. The broadband dual-circular polarization low-cost phased array antenna element according to claim 1, characterized in that, The slot feeding structure is surrounded by multiple metal pillars evenly distributed along the four sides of the slot feeding structure. Each metal pillar extends from the lower surface of the fourth dielectric substrate to the slot layer. The structure composed of the multiple metal pillars and the third dielectric substrate together form a feeding resonant cavity. The resonant frequency of the antenna array elements can be adjusted by adjusting the size of each metal pillar and the spacing between adjacent metal pillars.

7. The broadband dual-circular polarization low-cost phased array antenna element according to claim 1, characterized in that, The cutout portion of the first dielectric substrate is any one of rectangular, hexagonal, and circular shapes; the dielectric portion surrounding the cutout portion serves as a support portion for the air medium.

8. The broadband dual-circular polarization low-cost phased array antenna element according to claim 7, characterized in that, When the cutout portion of the first dielectric substrate is rectangular, the first dielectric substrate has a U-shaped structure, and the frame portion of the U-shaped structure is a dielectric substrate with a dielectric constant of 2-4 to support the parasitic radiation layer.

9. The broadband dual-circular polarization low-cost phased array antenna element according to claim 1, characterized in that, Both the metal patch in the parasitic radiation layer and the metal patch in the excitation radiation layer have symmetrical geometric structures, and their dimensions are smaller than or equal to the dimensions of the air cavity in the first dielectric substrate.

10. A phased array antenna array, characterized in that, It includes multiple phased array antenna elements as described in any one of claims 1-9, wherein the multiple antenna elements are arranged in a predetermined direction to form an array structure.

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