Circularly polarized reflecting element and beam reconfigurable reflecting antenna

Abstract

The application belongs to the technical field of antennas and relates to a circularly polarized reflecting unit and a beam reconfigurable reflecting antenna. The circularly polarized reflecting unit comprises a patch layer, a dielectric layer and a ground layer. The patch layer comprises a first patch and four second patches. The first patch is in a square structure. The second patch is in an elliptical structure, the long axis of which is collinear with one symmetric axis of the square structure, and the short axis is parallel to the corresponding side of the square structure. One side of the elliptical structure is tangent to the square structure, and the other side of the elliptical structure has a cutting groove, the straight side of which is parallel to the adjacent side of the square structure. The four second patches form a "cross" structure. Each side of the first patch is connected to the corresponding second patch through a diode. At the same time, the working states of the two diodes opposite to each other are the same, and the working states of the two diodes adjacent to each other are opposite, so as to realize circularly polarized reflection. The application can realize circularly polarized reflection.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and in particular to a circularly polarized reflective element and a beam-reconfigurable reflective antenna. Background Technology

[0002] In the increasingly complex application environment of large-scale detection systems, the new generation of reconnaissance systems has put forward requirements such as beam scanning and the ability to radiate circularly polarized electromagnetic waves. The beam scanning function of the antenna can improve the reconnaissance efficiency of the reconnaissance system, while the circularly polarized antenna can reduce other external interferences and can also receive electromagnetic waves of any polarization.

[0003] In the existing technology, traditional methods for realizing beam scanning and circular polarization functions include phased arrays and programmable reflector arrays.

[0004] Phased arrays are very expensive and are gradually no longer the preferred method for achieving beam scanning.

[0005] Programmable reflector arrays are antenna design systems that control the phase of each reflector array element by controlling the opening or closing of the PIN diodes loaded into each reflector element. By changing the coding state of the reflector array, the beam deflection angle can be changed, thereby flexibly changing the beam scanning angle of the antenna. Compared with phased array technology, it has lower cost and better concealment. However, programmable reflector arrays have a narrow bandwidth, which cannot meet the requirements of wideband system reconnaissance. Summary of the Invention

[0006] Therefore, it is necessary to provide a circularly polarized reflective element and a beam-reconfigurable reflective antenna that have broadband circular polarization characteristics and can realize broadband circular polarization reflection in response to the above-mentioned technical problems.

[0007] A circularly polarized reflective unit includes: a patch layer, a dielectric layer, and a ground layer stacked sequentially from top to bottom;

[0008] The patch layer includes: a first patch disposed at the center of the dielectric layer and four second patches arranged in an array;

[0009] The first patch is a square structure, and the four sides of the square structure correspond one-to-one with the four second patches;

[0010] The second patch has an elliptical structure, the major axis of which is collinear with one axis of symmetry of the square structure, and the minor axis of which is parallel to the corresponding side of the square structure. One side of the elliptical structure is tangent to the square structure, and one side of the elliptical structure has a groove, the straight edge of which is parallel to the adjacent side of the square structure, so that the second patch is spaced apart from the corresponding side of the square structure. The four second patches are centrally symmetrically distributed to form a cross shape.

[0011] Each edge of the first patch is connected to the corresponding second patch by a diode. At the same time, the two opposing diodes operate in the same state, and the two adjacent diodes operate in opposite states to achieve circular polarization reflection.

[0012] In one embodiment, the ratio of the length of the major axis to the length of the minor axis in the second patch is 21:16.

[0013] In one embodiment, the major axis length of the second patch is 14 times the distance between the first patch and the second patch.

[0014] In one embodiment, the patch layer further includes: four third patches in an elliptical structure;

[0015] The third patch is symmetrically positioned between two adjacent second patches, and the area of ​​the third patch is smaller than the area of ​​the second patch.

[0016] In one embodiment, the major axis of the third patch is equal in length to the major axis of the second patch.

[0017] In one embodiment, the ratio of the length of the major axis to the length of the minor axis of the third patch is 7:1.

[0018] In one embodiment, the distance between the third patch and the first patch is equal to the distance between the second patch and the first patch.

[0019] In one embodiment, the distance between the third patch and the first patch is equal to the length of the minor axis of the third patch.

[0020] In one embodiment, the dielectric layer has a square structure, and any side of the first patch forms a 45° angle with any side of the dielectric layer.

[0021] A beam-reconfigurable reflective antenna includes: multiple circularly polarized reflective elements;

[0022] Multiple circularly polarized reflective elements are arranged in an array, and the diodes in different circularly polarized reflective elements operate in different states to achieve beam reconfigurability of the reflective antenna.

[0023] The aforementioned circularly polarized reflective unit features a square first patch, an elliptical second patch, and a diode connecting the first and second patches. A groove is cut into the second patch near the first patch to shorten the relative current path using an arc-shaped structure, reducing energy loss and increasing the current contact area. This ensures that current flows to the second patch when the diode is conducting. Furthermore, the four second patches can generate two mutually orthogonal linearly polarized electric fields with a 90-degree phase difference in the x and y axes, achieving 1-bit phase resolution and circular polarization characteristics. Additionally, it reduces resistance, increases amplitude, improves reflectivity and reflection effect, and expands the bandwidth of circular polarization, enabling broadband circularly polarized reflection.

[0024] The aforementioned beam-reconfigurable reflective antenna, with multiple circularly polarized reflective elements arranged in an array to form a reflective array, and the diodes in different circularly polarized reflective elements operating in different states, enables the reflective antenna to be beam-reconfigurable. This allows it to be used in next-generation communication systems and promotes the upgrade of next-generation detection systems. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of a circularly polarized reflective unit in one embodiment;

[0026] Figure 2 This is a schematic diagram showing the dimensions of a circularly polarized reflective unit in one embodiment;

[0027] Figure 3 This is a graph showing the S-parameters versus frequency of a circularly polarized reflective unit in one embodiment.

[0028] Figure 4 This is a graph showing the phase versus frequency of a circularly polarized reflective unit in two different states in one embodiment.

[0029] Figure 5 This is a coding distribution diagram of the reflective array of a beam-reconfigurable reflective antenna in one embodiment when the beam deflection is 0 degrees.

[0030] Figure 6 This is a coding distribution diagram of the reflective array of a beam-reconfigurable reflective antenna in one embodiment when the beam is deflected by 10 degrees;

[0031] Figure 7 This is a coding distribution diagram of the reflective array of a beam-reconfigurable reflective antenna in one embodiment when the beam is deflected by 20 degrees;

[0032] Figure 8 This is a coding distribution diagram of the reflective array of a beam-reconfigurable reflective antenna in one embodiment when the beam is deflected by 30 degrees;

[0033] Figure 9This is a coding distribution diagram of the reflective array of a beam-reconfigurable reflective antenna in one embodiment when the beam is deflected by 40 degrees;

[0034] Figure 10 This is a diagram showing the coding distribution of the reflective array of a beam-reconfigurable reflective antenna in one embodiment when the beam is deflected by 50 degrees.

[0035] Figure 11 This is a simulation pattern of the beam reconfigurable reflective antenna performing beam scanning at 15 GHz with different scanning angles in one embodiment;

[0036] Figure 12 This is a simulation pattern of the beam reconfigurable reflective antenna performing beam scanning at 17 GHz with different scanning angles in one embodiment.

[0037] Figure label:

[0038] Surface mount layer 1, first surface mount 11, second surface mount 12, third surface mount 13, diode 14;

[0039] Dielectric layer 2;

[0040] Floor layer 3. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0042] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application 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 indicator will also change accordingly.

[0043] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0044] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0046] This application provides a circularly polarized reflective unit, such as Figure 1 As shown, in one embodiment, it includes: a patch layer, a dielectric layer, and a floor layer, which are stacked sequentially from top to bottom, and the dielectric layer and the floor layer are square structures of equal size.

[0047] The patch layer is the reflective part and is made of metal.

[0048] The dielectric layer is the carrier layer, providing a substrate for supporting the patch layer and the ground layer, and is made of non-metallic materials.

[0049] The floor layer is the grounding part and is made of metal.

[0050] The surface mount layer includes a first surface mount, a second surface mount, and a diode.

[0051] The first patch is a square structure and is located at the top center of the dielectric layer.

[0052] The second patch has an elliptical structure, and there are four of them. The four second patches correspond one-to-one with the four sides of the square structure. They are arranged in an array around the first patch and are centrally symmetrical about the top center of the dielectric layer. The major axis of the elliptical structure is collinear with one axis of symmetry of the square structure, and the minor axis of the elliptical structure is parallel to the corresponding side of the square structure. One side of the elliptical structure is tangent to the square structure and has a groove on one side. The axis of symmetry of the groove is the major axis of the elliptical structure, and the straight edge of the groove is parallel to the adjacent side of the square structure, so that the corresponding sides of the second patch and the square structure are spaced apart. The four second patches are centrally symmetrically distributed, with one corresponding end connected to the first patch and the other corresponding end extending in four different directions to form a cross shape.

[0053] There are four diodes, which are respectively located between the four sides of the first patch and the four second patches, and are respectively connected to one side of the first patch and the corresponding second patch. At the same time, the two opposing diodes have the same operating state, and the two adjacent diodes have opposite operating states, so as to achieve circular polarization reflection.

[0054] In this application, the diodes are PIN diodes. When two opposing diodes are simultaneously turned on and the other two opposing diodes are simultaneously turned off, the reflective unit is in state 1. When two opposing diodes are simultaneously turned off and the other two opposing diodes are simultaneously turned on, the reflective unit is in state 0.

[0055] The aforementioned circularly polarized reflective unit features a square first patch, an elliptical second patch, and a diode connecting the first and second patches. A groove is cut into the second patch near the first patch to shorten the relative current path using an arc-shaped structure, reducing energy loss and increasing the current contact area. This ensures that current flows to the second patch when the diode is conducting. Furthermore, the four second patches can generate two mutually orthogonal linearly polarized electric fields with a 90-degree phase difference in the x and y axes, achieving 1-bit phase resolution and circular polarization characteristics. Additionally, it reduces resistance, increases amplitude, improves reflectivity and reflection effect, and expands the bandwidth of circular polarization, enabling broadband circularly polarized reflection.

[0056] Preferably, the ratio of the length of the major axis to the length of the minor axis in the second patch is 21:16, so as to effectively obtain a 90-degree phase difference and improve the circular polarization reflection performance of the unit.

[0057] More preferably, the major axis length of the second patch is 14 times the distance between the first patch and the second patch, so as to further improve the working bandwidth.

[0058] In one embodiment, the patch layer further includes a third patch, that is, the patch layer includes a first patch, a second patch, a third patch, and a diode.

[0059] The third patch has an elliptical structure and is symmetrically spaced between two adjacent second patches. The area of ​​the third patch is smaller than that of the second patch. There are four third patches, which are arranged in an array around the first patch and are centrally symmetrical about the top center of the dielectric layer. The four third patches correspond one-to-one with the four corners of the square structure, and the major axis of the third patch is collinear with the diagonal of the dielectric layer.

[0060] The placement of the third patch allows the electric field on each patch to be vector-decomposed into electric fields of equal amplitude along the x-axis and y-axis, thereby increasing the amplitude of the element and antenna reflection and improving the reflectivity.

[0061] Preferably, the major axis of the third patch is equal in length to the major axis of the second patch, so that the third patch does not significantly affect the 90-degree phase difference of the mutually orthogonal linear polarizations formed by the first patch, ensuring that the circular polarization performance of the antenna element is not affected while increasing the reflection amplitude.

[0062] More preferably, the ratio of the length of the major axis to the length of the minor axis of the third patch is 7:1, so as to ensure that the electric field on the third patch is concentrated in the diagonal direction of the dielectric layer, and further expand the area of ​​the patch on the reflective unit, so that the electric field in the diagonal direction is vector decomposed into an electric field of equal amplitude in the x-axis direction and an electric field in the y-axis direction, thereby obtaining a higher reflection amplitude and working bandwidth.

[0063] More preferably, the distance between the third patch and the first patch is equal to the distance between the second patch and the first patch, so as to improve radiation performance and ensure radiation effect.

[0064] More preferably, the distance between the third patch and the first patch is equal to the length of the minor semi-axis of the third patch, so as to further improve the reflection amplitude.

[0065] In one embodiment, the dielectric layer has a square structure, and any side of the first patch forms a 45° angle with any side of the dielectric layer to balance x-polarization and y-polarization, without affecting the current direction itself, maintaining a relatively good amplitude, and reducing costs without affecting the performance of the cell.

[0066] Preferably, the side length of the dielectric layer is half the wavelength at the center frequency, so that after the element forms the antenna, the maximum scanning angle is increased to ±50 degrees. Here, the maximum angle refers to the scanning angle when the antenna gain drops by 3dB. In this application, the scanning angle reaches ±50 degrees when the antenna gain drops by 3dB, which is a significant advantage compared to the prior art where the gain drops by 3dB when the antenna scans to 30 degrees.

[0067] This application also provides a beam-reconfigurable reflective antenna, which in one embodiment includes: a plurality of circularly polarized reflective elements.

[0068] The aforementioned beam-reconfigurable reflective antenna, with multiple circularly polarized reflective elements arranged in an array to form a reflective array, and the diodes in different circularly polarized reflective elements operating in different states, enables the reflective antenna to be beam-reconfigurable. This allows it to be used in next-generation communication systems and promotes the upgrade of next-generation detection systems.

[0069] like Figure 2As shown, in a specific embodiment, the center frequency of the electromagnetic wave is 15 GHz, and the wavelength of the center frequency of the electromagnetic wave is 20 mm; the first patch is a square structure with a side length of 2 mm; the second patch is an elliptical structure with a major semi-axis of 2.1 mm, a minor semi-axis of 1.6 mm, and a distance of 0.3 mm from the first patch; the third patch is an elliptical structure with a major semi-axis of 2.1 mm, a minor semi-axis of 0.3 mm, and a distance of 0.3 mm from the first patch; the diode is a PIN diode; the dielectric layer is a square structure with a side length of 10.5 mm and a thickness of 2 mm, and the material is Rogers 5880; the ground plane is a square structure with a side length of 10.5 mm.

[0070] In simulation software, the equivalent circuit of a PIN diode is a series connection of a capacitor, a resistor, and an inductor. Specifically, the diode is in the conducting state when C = 0 F, R = 5.2 Ω, and L = 30 pH; and in the cutoff state when C = 25 fF, R = 0 Ω, and L = 30 pH.

[0071] Electromagnetic simulation was performed on the circularly polarized reflection unit in this embodiment, and the results are as follows: Figures 3 to 4 As shown.

[0072] like Figure 3 The graph shows the S-parameters versus frequency of the circularly polarized reflective element, where R... RCP-RCP This refers to an incident wave that is right-handedly polarized and a reflected wave that is right-handedly circularly polarized. R RCP-LCP This refers to an incident wave that is left-handedly polarized and a reflected wave that is right-handedly circularly polarized. R LCP-LCP This refers to an incident wave that is left-handed circularly polarized and a reflected wave that is left-handed circularly polarized. R LCP-RCP This means that the incident wave is a right-handed circularly polarized wave, and the reflected wave is a left-handed circularly polarized wave. It can be seen that R... RCP-LCP and R LCP-RCP The S-parameter values ​​are all higher than -1dB, indicating that the reflective unit of this application can achieve the reflection effect of circularly polarized electromagnetic waves in the frequency range of 14GHz-19GHz.

[0073] like Figure 4 The graphs shown depict the phase versus frequency of the circularly polarized reflector in two states. The three curves represent the phase versus frequency when the reflector is in state 0, the phase versus frequency when the reflector is in state 1, and the phase difference between the two states versus frequency, respectively. It can be seen that within the frequency range of 14GHz-19GHz, the phase difference between the two states of the circularly polarized reflector remains approximately 180 degrees, indicating that these two states are sufficient to achieve a 1-bit phase resolution.

[0074] Electromagnetic simulation was performed on the beam-reconfigurable reflective antenna in this embodiment, and the results are as follows: Figures 5 to 12 As shown.

[0075] like Figures 5 to 10 As shown, the reflective antenna of this application can achieve beam reconfiguration.

[0076] like Figure 11 As shown, when the scan angle is 0°, the horizontal axis corresponding to the maximum gain value is Theta = 0°; when the scan angle is 30°, the horizontal axis corresponding to the maximum gain value is Theta = 30°; and when the scan angle is 50°, the horizontal axis corresponding to the maximum gain value is Theta = 50°. Compared to the maximum gain value of the curve with a scan angle of 0°, the maximum gain value of the curve with a scan angle of 50° is lower, approximately 3dB. Therefore, at 15GHz, while ensuring a gain decrease within 3dB, the maximum beam scan angle is 50 degrees.

[0077] like Figure 12 As shown, similarly, at 17GHz, the maximum beam scanning angle is 50 degrees while ensuring a gain drop of less than 3dB.

[0078] 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.

[0079] 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 patent 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 all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A circularly polarized reflective unit, characterized in that, include: The layers are stacked from top to bottom: the patch layer, the medium layer, and the floor layer. The patch layer includes: a first patch disposed at the center of the dielectric layer and four second patches arranged in an array; The first patch has a square structure, and the four sides of the square structure correspond one-to-one with the four second patches; The second patch has an elliptical structure, the major axis of which is collinear with one axis of symmetry of the square structure, and the minor axis of which is parallel to the corresponding side of the square structure. One side of the elliptical structure is tangent to the square structure, and one side of the elliptical structure has a groove, the straight edge of which is parallel to the adjacent side of the square structure, so that the second patch is spaced apart from the corresponding side of the square structure. The four second patches are centrally symmetrically distributed to form a cross shape. Each edge of the first patch is connected to the corresponding second patch by a diode. At the same time, the two opposing diodes operate in the same state, and the two adjacent diodes operate in opposite states to achieve circular polarization reflection. The patch layer also includes: four third patches with an elliptical structure; The third patch is symmetrically positioned between two adjacent second patches, and the area of ​​the third patch is smaller than the area of ​​the second patch. The major axis of the third patch is equal in length to the major axis of the second patch; The ratio of the length of the major axis to the length of the minor axis of the third patch is 7:

1.

2. The circularly polarized reflective unit according to claim 1, characterized in that, The ratio of the length of the major axis to the length of the minor axis in the second patch is 21:

16.

3. A circularly polarized reflective unit according to claim 2, characterized in that, The major axis length of the second patch is 14 times the distance between the first patch and the second patch.

4. A circularly polarized reflective unit according to any one of claims 1 to 3, characterized in that, The distance between the third patch and the first patch is equal to the distance between the second patch and the first patch.

5. A circularly polarized reflective unit according to claim 4, characterized in that, The distance between the third patch and the first patch is equal to the length of the minor axis of the third patch.

6. A circularly polarized reflective unit according to any one of claims 1 to 3, characterized in that, The dielectric layer has a square structure, and any side of the first patch forms a 45° angle with any side of the dielectric layer.

7. A beam-reconfigurable reflective antenna, characterized in that, include: The circularly polarized reflective unit as described in any one of claims 1 to 6; Multiple circularly polarized reflective elements are arranged in an array, and the diodes in different circularly polarized reflective elements operate in different states to achieve beam reconfigurability of the reflective antenna.

Images