A circularly polarized reflectarray antenna element and reflectarray antenna

Abstract

The application belongs to the technical field of antennas and relates to a circularly polarized reflecting antenna unit and a reflecting array antenna. The circularly polarized reflecting antenna unit comprises, from top to bottom, a radiation layer, a first dielectric layer and a first ground layer; the radiation layer comprises four radiating elements, four diodes and four connecting pieces; the radiating element is in a fan-shaped structure and is connected with the first ground layer; the connecting piece is in a "one" shaped structure; one end of the connecting piece is arranged at the center of the first dielectric layer; the other end of the connecting piece is connected with the tip of one radiating element through one diode, so that all the connecting pieces form a "cross" shaped structure, and all the radiating elements are distributed in a spaced array around the center of the first dielectric layer; two diodes arranged oppositely form a group; one group of diodes is turned on and the other group of diodes is turned off, so as to realize the transformation of the circularly polarized reflecting phase. The application can realize the transformation of the circularly polarized reflecting phase of the antenna unit.

Description

Technical Field

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

[0002] With the development of the times and the progress of technology, antennas have also undergone rapid updates and changes.

[0003] Circularly polarized reflective array antennas have attracted widespread attention in wireless and satellite communications due to their excellent characteristics. Reflective arrays can avoid complex and lossy beamforming networks while increasing beam gain. Furthermore, since wireless communication is often dynamic and signal transmission is complex, requiring transmitting and receiving antennas to adjust beam direction in a timely manner, circularly polarized reflective arrays capable of independently controlling beam pointing are of great significance for wireless communication.

[0004] A conventional circularly polarized reflective array antenna first requires the construction of circularly polarized elements with reflective capabilities, and then the phase of the elements is changed through the phase compensation principle so that the reflected beam is focused in the desired direction.

[0005] However, existing circularly polarized reflective array antennas can only radiate beams in a fixed direction and do not have the ability to control the beam independently. Such antennas are no longer suitable for the increasingly developed wireless communication systems. Summary of the Invention

[0006] Therefore, it is necessary to provide a circularly polarized reflective antenna element and a reflective array antenna to address the above-mentioned technical problems. This can realize the circularly polarized beam reflection of the antenna element, thereby further generating a circularly polarized reflective array antenna, and the beam direction can be independently controlled.

[0007] A circularly polarized reflective antenna element includes: a radiating layer, a first dielectric layer, and a first ground layer stacked sequentially from top to bottom;

[0008] The radiating layer includes: four radiating elements, four diodes, and four connectors;

[0009] The radiating element has a fan-shaped structure and is connected to the first floor layer. The connecting element has an "I"-shaped structure. One end of the connecting element is located at the center of the first dielectric layer. The other end of the connecting element is connected to the tip of a radiating element through a diode, so that all the connecting elements form a cross-shaped structure. All the radiating elements are distributed in an interval array around the center of the first dielectric layer.

[0010] Two diodes positioned opposite each other form a group, with one group of diodes conducting while the other group of diodes is cut off, in order to achieve a phase change in circularly polarized reflection.

[0011] In one embodiment, the fan-shaped structure is provided with two fan-shaped gaps;

[0012] The two fan-shaped gaps are symmetrically distributed about the axis of symmetry of the fan-shaped structure, and the arc edges of the two fan-shaped gaps are parallel to the arc edges of the fan-shaped structure.

[0013] In one embodiment, the first dielectric layer is provided with a plurality of through channels, and each through channel is provided with a metal tube;

[0014] All the metal tubes are divided into four equal groups to connect to a radiating element and the first floor layer, respectively.

[0015] In one embodiment, the radiating layer is used as an electric dipole, and all the metal tubes are used as magnetic dipoles, with the electric dipoles and magnetic dipoles operating alternately.

[0016] In one embodiment, three metal tubes are grouped together, and the three metal tubes corresponding to the same radiating element form a right-angled triangular prism structure.

[0017] In one embodiment, the first floor layer is provided with two vertically arranged power supply slots;

[0018] The power supply channel has a cuboid structure, and the centers of the two power supply channels coincide with the center of the first floor layer, and there is an angle between the power supply channel and the connector.

[0019] In one embodiment, the included angle is 45°.

[0020] In one embodiment, the length of the feed slot is equal to the length of the radiation layer along the length direction of the feed slot.

[0021] In one embodiment, it further includes: a second dielectric layer and a second floor layer;

[0022] The radiation layer, the first dielectric layer, the first floor layer, the second dielectric layer, and the second floor layer are stacked sequentially.

[0023] A reflective array antenna includes: multiple circularly polarized reflective antenna elements and a feed source;

[0024] Multiple circularly polarized reflective antenna elements are arranged in a rectangular array to form a circularly polarized reflective array;

[0025] The feed source and the circularly polarized reflective array are spaced apart so that the reflected beam scanning can be achieved by changing the operating state of the diodes in different circularly polarized reflective antenna elements.

[0026] The aforementioned circularly polarized reflective antenna unit has radiating elements and connecting elements arranged on the radiating layer, connected by diodes. Two diodes arranged opposite each other form a group, with one group of diodes conducting and the other group of diodes cut off, to connect different paths and generate a phase difference. The reflective antenna unit simultaneously realizes the change of radiation direction and the reversal of circularly polarized current, thereby realizing the reflection of co-polarized waves and circularly polarized waves. Specifically, when the incident wave is a left circularly polarized wave, it reflects a left circularly polarized wave; when the incident wave is a right circularly polarized wave, it reflects a right circularly polarized wave, that is, it has circularly polarized reflection function. In contrast, in the prior art, metal reflectors can only realize the change of radiation direction, but cannot realize the reversal of circularly polarized current or the phase adjustment. In other words, the beam reflected back by the metal reflector will not be a focused beam. Furthermore, a fan-shaped bandgap, alternating electric and magnetic dipoles, multiple sets of metal tubes, and the length relationship between the feed slot and the radiating layer were designed to improve the reflection bandwidth to varying degrees. This ensures that bandwidth is not sacrificed when achieving circular polarization reflection, thus combining the characteristics of circular polarization reflection and broadband performance, achieving broadband circular polarization beam reflection. Even further, based on the antenna elements, the antenna elements can be arranged into an array to generate a circular polarization reflection array antenna.

[0027] The aforementioned reflective array antenna can reflect both left and right circularly polarized beams within a relatively wide operating bandwidth. Simultaneously, by adjusting the conduction and cutoff states of the PIN diodes according to different phase compensation conditions, the antenna element states are controlled. Through phase modulation of multiple antenna elements, beam focusing is achieved, and unlike existing technologies where the focusing direction is fixed, the beam pointing can be independently controlled, enabling beam scanning at different angles and providing independent beam control capability. Furthermore, the antenna maintains relatively stable gain within a beam scanning angle range of ±30°, with an operating frequency band of 5.17GHz-8.88GHz and a relative bandwidth of 52.8%. This reflective array antenna possesses the characteristics of circularly polarized beam reflection, wide bandwidth, and beam scanning, making it adaptable to various existing and future wireless communication scenarios and offering broad application prospects for different communication environment requirements. Attached Figure Description

[0028] Figure 1 This is a three-dimensional schematic diagram of a circularly polarized reflective antenna element in one embodiment;

[0029] Figure 2 This is a side view of a circularly polarized reflective antenna element in one embodiment;

[0030] Figure 3 This is a top view of a circularly polarized reflective antenna element in one embodiment;

[0031] Figure 4This is a diagram showing the radiating layer size parameters of a circularly polarized reflective antenna element in one embodiment;

[0032] Figure 5 This is a circular polarization reflectivity diagram of a reflective array antenna in two states in one embodiment;

[0033] Figure 6 This is a reflection phase curve diagram of a reflective array antenna in two states in one embodiment;

[0034] Figure 7 This is a diagram showing the distribution of circularly polarized reflective antenna elements in one embodiment of a reflective array antenna when the beam is pointed at 0°.

[0035] Figure 8 This is a diagram showing the distribution of circularly polarized reflective antenna elements in one embodiment of a reflective array antenna when the beam is pointed at 10°.

[0036] Figure 9 This is a diagram showing the distribution of circularly polarized reflective antenna elements in one embodiment of a reflective array antenna when the beam is pointed at 20°.

[0037] Figure 10 This is a diagram showing the distribution of circularly polarized reflective antenna elements in one embodiment of a reflective array antenna when the beam is pointed at 30°.

[0038] Figure 11 This is a beam scanning pattern of a reflective array antenna at 0° in one embodiment;

[0039] Figure 12 This is a beam scanning pattern of a reflective array antenna at 10° in one embodiment;

[0040] Figure 13 This is a beam scanning pattern of a reflective array antenna at 20° in one embodiment;

[0041] Figure 14 This is a beam scanning pattern of a reflective array antenna at 30° in one embodiment.

[0042] Figure label:

[0043] Radiation layer 1, radiation element 11, diode 12, connector 13, fan-shaped bandgap 14;

[0044] First dielectric layer 2, metal tube 21;

[0045] First floor layer 3, power supply trough 31;

[0046] Second dielectric layer 4;

[0047] Air layer 5;

[0048] Second floor layer 6. Detailed Implementation

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] This application provides a circularly polarized reflective antenna element, such as Figures 1 to 3 As shown, in one embodiment, it includes: a radiating layer, a first dielectric layer, and a first floor layer.

[0055] The radiating layer, the first dielectric layer, and the first floor layer are stacked sequentially from top to bottom, and the first dielectric layer and the first floor layer are square structures of equal size.

[0056] The radiating layer includes four radiating elements, four diodes, and four connectors. The radiating elements are fan-shaped, with their curved edges pointing perpendicular to the first dielectric layer, and are connected to the first ground plane. All radiating elements are arranged in a spaced array around the center of the first dielectric layer, exhibiting both axial symmetry and centrosymmetry. Each diode connects to a radiating element and a connector at its two ends; PIN diodes can be used. The connectors are in a "I" shape, with one end located at the center of the first dielectric layer and the other end connected to the tip of a radiating element via a diode. Any two adjacent connectors are perpendicularly connected to each other, forming a cross shape. It should be noted that the axes of symmetry of the fan-shaped structure and the length axis of the "I"-shaped structure are both located on the diagonal of the first dielectric layer.

[0057] Preferably, the fan-shaped structure has two fan-shaped band gaps; the two fan-shaped band gaps are symmetrically distributed about the axis of symmetry of the fan-shaped structure, and the arc edges of the two fan-shaped band gaps are parallel to the arc edges of the fan-shaped structure, so as to improve the reflection bandwidth.

[0058] The first dielectric layer is a non-metallic layer that provides a supporting substrate for the radiating layer.

[0059] Preferably, the first dielectric layer is provided with multiple through channels, and each through channel is provided with a metal tube; all the metal tubes are divided into four equal groups, that is, four metal tube groups, to connect a radiating element and the first floor layer respectively, and the cross-section of the metal tube group is both axially symmetric and centrally symmetric.

[0060] More preferably, the radiating layer is used as an electric dipole, and all the metal tubes are used as magnetic dipoles. The electric dipoles and magnetic dipoles work alternately to significantly improve the reflection bandwidth.

[0061] More preferably, three metal tubes are used as a group of metal tubes, and the three metal tubes corresponding to the same radiating element form a right triangular prism structure with an isosceles right triangle cross-section. That is, the metal tubes are simultaneously arranged perpendicular to the radiating layer and the first floor layer, and the corresponding ends of a group of metal tubes are connected to form an isosceles right triangle to further improve the reflection bandwidth.

[0062] The first floor layer is a metal layer. Two power supply slots are provided on the first floor layer. The two power supply slots are rectangular structures of equal size and are arranged vertically. The length direction of the power supply slots is parallel to two opposite sides of the first floor layer. The center of the two power supply slots coincides with the center of the first floor layer, and there is an angle between the power supply slots and the connectors to ensure the power supply effect during operation.

[0063] Preferably, the angle between the feed slot and the connector is 45° to ensure better feeding effect and enable the antenna unit to reach the best working state.

[0064] More preferably, the length of the feed slot is equal to the length of the radiation layer along the length of the feed slot, so as to further improve the reflection bandwidth and achieve the best reflection bandwidth when the fan-shaped bandgap and the dipoles are working alternately.

[0065] In one embodiment, it further includes: a second dielectric layer and a second ground layer; that is, the circularly polarized reflective antenna element includes: a radiating layer, a first dielectric layer, a first ground layer, a second dielectric layer and a second ground layer; the radiating layer, the first dielectric layer, the first ground layer, the second dielectric layer and the second ground layer are stacked sequentially from top to bottom, and the first dielectric layer, the first ground layer, the second dielectric layer and the second ground layer are square structures of equal size to improve the reflection effect and isolate the first ground layer and the second ground layer.

[0066] In one embodiment, the device further includes an air layer disposed between the second dielectric layer and the second ground plane. That is, the circularly polarized reflective antenna element includes a radiating layer, a first dielectric layer, a first ground plane, a second dielectric layer, an air layer, and a second ground plane. These layers are stacked sequentially from top to bottom so that the air layer works in conjunction with the other layers to achieve and maintain a stable gain. Of course, a support pillar is provided between the second dielectric layer and the second ground plane to ensure the existence of the air layer. The support pillar is made of a non-metallic material, and its specific number, location, and size are existing technologies and will not be elaborated here.

[0067] It should be noted that the radiation layer, the first floor layer, and the second floor layer are all made of metallic materials, while the first dielectric layer and the second dielectric layer are both made of non-metallic materials.

[0068] The aforementioned circularly polarized reflective antenna unit has radiating elements and connecting elements arranged on the radiating layer, connected by diodes. Two diodes arranged opposite each other form a group, with one group of diodes conducting and the other group of diodes cut off, to connect different paths and generate a phase difference. The reflective antenna unit simultaneously realizes the change of radiation direction and the reversal of circularly polarized current, thereby realizing the reflection of co-polarized waves and circularly polarized waves. Specifically, when the incident wave is a left circularly polarized wave, it reflects a left circularly polarized wave; when the incident wave is a right circularly polarized wave, it reflects a right circularly polarized wave, that is, it has circularly polarized reflection function. In contrast, in the prior art, metal reflectors can only realize the change of radiation direction, but cannot realize the reversal of circularly polarized current or the phase adjustment. In other words, the beam reflected back by the metal reflector will not be a focused beam. Furthermore, a fan-shaped bandgap, alternating electric and magnetic dipoles, multiple sets of metal tubes, and the length relationship between the feed slot and the radiating layer were designed to improve the reflection bandwidth to varying degrees. This ensures that bandwidth is not sacrificed when achieving circular polarization reflection, thus combining the characteristics of circular polarization reflection and broadband performance, achieving broadband circular polarization beam reflection. Even further, based on the antenna elements, the antenna elements can be arranged into an array to generate a circular polarization reflection array antenna.

[0069] This application also provides a reflective array antenna, which in one embodiment includes: a plurality of circularly polarized reflective antenna elements and a feed source; the plurality of circularly polarized reflective antenna elements are distributed in a rectangular array to form a circularly polarized reflective array; the feed source and the circularly polarized reflective array are spaced apart to achieve reflected beam scanning by changing the operating state of the diodes in different circularly polarized reflective antenna elements.

[0070] The working process of the reflective array antenna is as follows: the feed horn radiates a circularly polarized wave, which illuminates the circularly polarized reflective array (i.e., the reflective metasurface) after traveling a certain distance. The surface current of the circularly polarized wave flows through the connector, a pair of PIN diodes in the conducting state, and the radiating element of the fan-shaped structure. Then, it is transmitted to the first ground plane through the metal tube (magnetic dipole) of the first dielectric layer. It is then coupled to the second ground plane again through the feed slot of the first ground plane, and finally the reflection of the circularly polarized beam is completed. The circularly polarized reflective array changes the radiation direction and current direction of the circularly polarized wave, thereby realizing the reflection of the same circular polarization.

[0071] On a microscopic level, within one oscillation period T of electromagnetic wave propagation, the magnetic dipole operates from t = -T / 2 to t = T / 2, while the electric dipole operates from t = T / 2 to t = 3T / 2. On a macroscopic level, they operate in different frequency bands, which constitute the broadband operating bandwidth.

[0072] The aforementioned reflective array antenna can reflect both left and right circularly polarized beams within a relatively wide operating bandwidth. Simultaneously, by adjusting the conduction and cutoff states of the PIN diodes according to different phase compensation conditions, the antenna element states are controlled. Through phase modulation of multiple antenna elements, beam focusing is achieved, and unlike existing technologies where the focusing direction is fixed, the beam pointing can be independently controlled, enabling beam scanning at different angles and providing independent beam control capability. Furthermore, the antenna maintains relatively stable gain within a beam scanning angle range of ±30°, with an operating frequency band of 5.17GHz-8.88GHz and a relative bandwidth of 52.8%. This reflective array antenna possesses the characteristics of circularly polarized beam reflection, wide bandwidth, and beam scanning, making it adaptable to various existing and future wireless communication scenarios and offering broad application prospects for different communication environment requirements.

[0073] In one specific embodiment, the circularly polarized reflective antenna element includes: a radiating layer, a first dielectric layer, a first ground plane, a second dielectric layer, and a second ground plane, wherein:

[0074] The radiating element of the radiating layer is a fan-shaped structure with a radius of 5.8 mm and an arc of 90°. The distance between adjacent fan-shaped structures is 1.4 mm. The distance between the fan-shaped gap and the arc edge of the radiating element is 0.3 mm. The width of the fan-shaped gap is 1 mm, and the distance between two fan-shaped gaps is 0.8 mm. The length of the connector is 1 mm, and the width is 0.4 mm. Specific dimensional parameters of the radiating layer are as follows: Figure 4 As shown.

[0075] The first dielectric layer is made of Rogers RT5880 material with a dielectric constant of 2.2, a square cross-section with a side length of 15mm and a thickness of 3mm; the radius of the metal tube is 0.2mm, and the leg length of the isosceles right triangle formed by the same group of metal tubes is 0.7mm; the first ground plane has a square cross-section with a side length of 15mm and a thickness of 0.035mm; the length of the feed slot is 13mm and the width is 0.7mm; the second dielectric layer is made of Rogers RO4003 material with a dielectric constant of 3.55, a square cross-section with a side length of 15mm and a thickness of 0.203mm; the thickness of the air layer is 3mm; the cross-section of the second ground plane has a square cross-section with a side length of 15mm and a thickness of 0.035mm.

[0076] In the antenna unit described above, when the PIN diode is turned on, it is equivalent to a 7.8Ω resistor connected in series with a 30pH inductor; when it is turned off, it is equivalent to a 0.025pF capacitor connected in series with a 30pH inductor.

[0077] Circular polarization radiation states are divided into left-hand circular polarization and right-hand circular polarization. If the polarization surface rotates with time and forms a right-hand spiral relationship with the direction of electromagnetic wave propagation, it is right-hand circular polarization; conversely, if it forms a left-hand spiral relationship, it is left-hand circular polarization.

[0078] When PIN diodes A and C are turned on, and PIN diodes B and D are turned off, the antenna element is in the "0" state.

[0079] When PIN diodes B and D are turned on, and PIN diodes A and C are turned off, the antenna element is in state "1".

[0080] Based on the aforementioned circularly polarized reflective antenna element, a 16×16 reflective array antenna was designed.

[0081] The above-mentioned reflective array antenna was simulated using the full-wave electromagnetic simulation software CST, and the results are as follows: Figures 4 to 13 As shown.

[0082] like Figure 5 As shown, a reflective array is generally defined to function normally when its reflectivity is greater than 0.8. Based on this, the operating frequency band of this antenna is 5.17GHz-8.88GHz, with a relative bandwidth of 52.8%.

[0083] like Figure 6 As shown, the phase difference between the "0" and "1" states within the operating frequency band is 180° to achieve 1-bit beam scanning. During beam scanning, different antenna elements require different phase compensations. The state of the antenna element can be defined based on the magnitude of the compensation phase: when the antenna element's compensation phase is -90° to +90°, it is defined as being in the "0" state; when the compensation phase is +90° to +270°, it is defined as being in the "1" state. A reflective array antenna is constructed according to this rule to achieve beam scanning functionality.

[0084] like Figures 7 to 10 As shown, beam scanning at the corresponding angle can be achieved by adjusting the conduction and cutoff of the PIN diode according to the different distribution states of the circularly polarized reflective antenna elements.

[0085] like Figures 11 to 14 As shown, the beam pointing angle of the reflective array antenna is consistent with expectations, and the beam gain remains stable without significant decrease due to the increase in scanning angle.

[0086] 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.

[0087] 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 antenna element, characterized in that, include: The radiation layer, the first dielectric layer, and the first floor layer are stacked sequentially from top to bottom; The radiating layer includes: four radiating elements, four diodes, and four connectors; The radiating element has a fan-shaped structure and is connected to the first floor layer. The connecting element has an "I"-shaped structure. One end of the connecting element is located at the center of the first dielectric layer. The other end of the connecting element is connected to the tip of a radiating element through a diode, so that all the connecting elements form a cross-shaped structure. All the radiating elements are distributed in an interval array around the center of the first dielectric layer. Two diodes positioned opposite each other form a group, with one group of diodes conducting and the other group of diodes cut off, to achieve a phase change in circularly polarized reflection, thus realizing the reflection of co-polarized waves and the reflection of circularly polarized waves. The first dielectric layer has multiple through channels, each of which contains a metal tube; all the metal tubes are divided into four equal groups to connect to a radiating element and the first floor layer respectively; the radiating layer is an electric dipole, and all the metal tubes are magnetic dipoles, with the electric dipoles and magnetic dipoles working alternately; three metal tubes are grouped together, and the three metal tubes corresponding to the same radiating element form a right-angled triangular prism structure.

2. The circularly polarized reflective antenna element according to claim 1, characterized in that, The fan-shaped structure is provided with two fan-shaped gaps; The two fan-shaped gaps are symmetrically distributed about the axis of symmetry of the fan-shaped structure, and the arc edges of the two fan-shaped gaps are parallel to the arc edges of the fan-shaped structure.

3. A circularly polarized reflective antenna element according to claim 1 or 2, characterized in that, The first floor layer is provided with two vertically arranged power supply slots; The power supply channel has a cuboid structure, and the centers of the two power supply channels coincide with the center of the first floor layer, and there is an angle between the power supply channel and the connector.

4. A circularly polarized reflective antenna element according to claim 3, characterized in that, The included angle is 45°.

5. A circularly polarized reflective antenna element according to claim 4, characterized in that, The length of the feed slot is equal to the length of the radiation layer along the length direction of the feed slot.

6. A circularly polarized reflective antenna element according to claim 1 or 2, characterized in that, Also includes: The second dielectric layer and the second floor layer; The radiation layer, the first dielectric layer, the first floor layer, the second dielectric layer, and the second floor layer are stacked sequentially.

7. A reflective array antenna, characterized in that, include: The circularly polarized reflective antenna element and feed source as described in any one of claims 1 to 6; Multiple circularly polarized reflective antenna elements are arranged in a rectangular array to form a circularly polarized reflective array; The feed source and the circularly polarized reflective array are spaced apart so that the reflected beam scanning can be achieved by changing the operating state of the diodes in different circularly polarized reflective antenna elements.

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