A circularly polarized coded antenna with flexible beam control

Abstract

This invention relates to the field of antenna technology and provides a circularly polarized coded antenna with flexibly adjustable beam. It includes an array composed of multiple metasurface elements arranged periodically. Each metasurface element comprises a first metal patch, a first dielectric substrate, a second metal patch, a second dielectric substrate, a third dielectric substrate, and a third metal patch stacked from top to bottom. It also includes a metal via penetrating the second metal patch, connecting the first and third metal patches. This invention solves the problems of high cost and complex design of traditional phased arrays, as well as the need for mechanical rotation in Risley prism antennas. It has the advantages of low cost, easy integration, and reconfigurability, and is suitable for fields such as 5G / 6G communication, radar detection, and satellite navigation.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, specifically to a circularly polarized coded antenna with flexibly adjustable beam. Background Technology

[0002] Traditional antennas are non-reconfigurable and lack flexible controllability. Traditional methods for achieving beam deflection include phased arrays and Risley prism antennas. Phased arrays are complex and costly, hindering large-scale deployment. Risley prism antennas achieve beam deflection by rotating two layers of metasurfaces with linear phase gradients. This method requires addressing circular polarization decoupling during circular polarization beam scanning and necessitates the use of motors to ensure precise rotation of the two metasurface layers. Reconfigurable coded metasurface antennas overcome the inherent limitations of these two approaches, offering potential for low cost and large-scale application. Furthermore, reconfigurable transmission-reflection metasurface structures can determine whether an incident wave is transmitted or reflected by judging its polarization state, increasing the antenna's controllability.

[0003] Therefore, in view of the above situation, there is an urgent need to provide a circularly polarized coded antenna with flexible beam adjustment to overcome the shortcomings in current practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide a circularly polarized coded antenna with flexible beam control, aiming to solve the problems mentioned in the background art.

[0005] The present invention is implemented as follows: a circularly polarized coded antenna with flexibly adjustable beam includes an array composed of multiple metasurface units arranged periodically, wherein the metasurface unit includes a first metal patch, a first dielectric substrate, a second metal patch, a second dielectric substrate, a third dielectric substrate, and a third metal patch stacked from top to bottom;

[0006] It also includes a metal through-hole that penetrates the second metal patch, the metal through-hole connecting the first metal patch and the third metal patch.

[0007] As a further aspect of the present invention: the first metal patch includes a fifth metal patch and a fourth metal patch and a sixth metal patch that are symmetrical about the center of the fifth metal patch;

[0008] A second PIN diode is loaded between the fourth and fifth metal patches, and a first PIN diode is loaded between the fifth and sixth metal patches.

[0009] As a further aspect of the present invention: by controlling the on / off states of the first PIN diode and the second PIN diode, the antenna can operate in two phase states:

[0010] When the first PIN diode is turned on and the second PIN diode is turned off, the unit is in state 0;

[0011] When the first PIN diode is off and the second PIN diode is on, the unit is in state 1;

[0012] The transmission phases corresponding to the 0 state and the 1 state are 180° apart to achieve 1-bit phase resolution.

[0013] As a further aspect of the present invention: the structure of the fourth metal patch and the sixth metal patch both include two rectangles of different sizes and a flag-shaped patch. This structure is used to excite two orthogonal modes and generate a 90° phase difference so that the transmitted wave exhibits circular polarization characteristics.

[0014] As a further aspect of the present invention: the third metal patch comprises two rectangular metal patches arranged in a centrally symmetrical manner, used to reflect x-polarized incident waves and absorb the energy of y-polarized incident waves.

[0015] As a further aspect of the present invention: the second metal patch is a metal floor, and a circular isolation ring is provided at the center of the second metal patch, and the metal through hole passes through the circular isolation ring to isolate the reflective function of the third metal patch from the transmissive function of the first metal patch.

[0016] As a further aspect of the present invention: the antenna operates in a frequency band of 10.0 GHz to 12.0 GHz, with a center frequency of 11.0 GHz.

[0017] As a further aspect of the present invention: the second dielectric substrate is composed of Rogers RO4450F with a thickness of 0.2 mm;

[0018] Both the first and third dielectric substrates are composed of Rogers RT5880 with a thickness of 3.2 mm.

[0019] As a further aspect of the present invention: the array has a size of 16 rows × 16 columns, with a total of 256 metasurface units. By encoding and controlling the phase state of each metasurface unit, the deflection of the transmitted circularly polarized beam within the spatial range can be achieved.

[0020] As a further aspect of the present invention, the radius of the circular isolation ring is 0.8 mm.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] Through a specially designed metasurface unit structure, dual functions of polarization control and phase control are achieved:

[0023] 1. Polarization control characteristics: It reflects x-polarized waves and transmits y-polarized waves as circular polarization, and the circular polarized waves can achieve multi-angle beam scanning;

[0024] 2. Phase modulation characteristics: The metasurface unit has a 1-bit phase resolution;

[0025] The antenna consists of 256 metasurface elements and operates in the 10.0 GHz–12.0 GHz frequency band. It has a 1-bit phase shift characteristic. When the incident electromagnetic wave is x-polarized, the metasurface array will reflect the x-polarized electromagnetic wave. When the incident electromagnetic wave is y-polarized, the metasurface array will transmit the circularly polarized electromagnetic wave. The antenna has polarization control function and has a strong advantage in modern radar detection, electronic countermeasures and other fields. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a three-dimensional structural diagram of the metasurface unit in this invention.

[0028] Figure 2 This is a schematic diagram of the structure of the first metal patch in this invention.

[0029] Figure 3 This is the amplitude-phase curve of the metasurface unit.

[0030] Figure 4 This is a normalized polar coordinate pattern with a scanning angle of 0 degrees.

[0031] Figure 5 This is a normalized polar coordinate pattern with a scanning angle of 10 degrees.

[0032] Figure 6 This is a normalized polar coordinate pattern with a scanning angle of 20 degrees.

[0033] Figure 7 This is a normalized polar coordinate pattern with a scanning angle of 30 degrees.

[0034] In the attached diagram: 1-first metal patch, 2-first dielectric substrate, 3-second metal patch, 4-second dielectric substrate, 5-third dielectric substrate, 6-third metal patch, 7-metal via, 8-first PIN diode, 9-second PIN diode, 10-fourth metal patch, 11-fifth metal patch, 12-sixth metal patch. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] The present invention will be further explained below with reference to specific embodiments.

[0039] Please see Figures 1-7 The present invention provides a circularly polarized coded antenna with flexibly adjustable beam, comprising an array of multiple metasurface units arranged periodically, wherein each metasurface unit consists of three dielectric substrates, two metal patches, metal vias 7 and a metal ground plane.

[0040] From top to bottom, they are: first metal patch 1, first dielectric substrate 2, second metal patch 3, second dielectric substrate 4, third dielectric substrate 5, and third metal patch 6;

[0041] The first metal patch 1 is printed on top of the first dielectric substrate 2, and the second metal patch 3, which is the metal ground plate, is printed below the first dielectric substrate 2 and above the second dielectric substrate 4.

[0042] The third metal patch 6 is printed below the third dielectric substrate 5;

[0043] The cylindrical metal through-hole 7 with a radius of 0.4 mm passes through the circular isolation ring with a radius of 0.8 mm on the second metal patch 3, connecting the first metal patch 1 and the third metal patch 6 together.

[0044] In a more specific example, the first metal patch 1 is composed of three parts: a fourth metal patch 10, a fifth metal patch 11, and a sixth metal patch 12.

[0045] The fifth metal patch 11 is mainly composed of a square and two rectangles, and is located at the center of the first metal patch 1.

[0046] The fourth metal patch 10 and the sixth metal patch 12 are centrally symmetrical;

[0047] The fourth metal patch 10 is composed of a large rectangle, a small rectangle, and a flag-shaped patch. Based on the large rectangle of 4.3mm × 3.0mm, the addition of the small rectangle and the flag-shaped patch is the key reason for the circular polarization effect of the structure. The structure changes the current path, so that the two currents in the orthogonal direction have a 90-degree phase difference, which makes the first metal patch 1 have circular polarization radiation capability. The fourth metal patch 10 and the sixth metal patch 12 on the first metal patch 1 are centrally symmetrical, thus forming a 1-bit phase resolution.

[0048] The loading of two PIN diodes, the first PIN diode 8 and the second PIN diode 9, can achieve 1-bit phase resolution;

[0049] The third metal patch 6 can reflect x-polarized electromagnetic waves into x-polarized electromagnetic waves, and can absorb the energy of y-polarized electromagnetic waves and transmit it to the first metal patch 1 through the metal through hole 7.

[0050] The two large rectangular patches of 5.2mm×2.8mm on the third metal patch 6 are centrally symmetrical. One of the large rectangular metal patches is connected to the patch at the center position, which can transmit the energy of the y-polarized wave received by the third metal patch 6 to the metal through hole 7.

[0051] The second metal patch 3 is a metal floor, used to isolate the energy between the reflective patch and the transmissive patch (i.e., to isolate the reflective function of the third metal patch 6 from the transmissive function of the first metal patch 1).

[0052] In embodiments of this invention, a reconfigurable transmissive-reflective metasurface unit is disclosed. Simultaneously, a high-efficiency reflective patch for receiving y-polarized electromagnetic waves is also disclosed. This reflective patch can reflect x-polarized electromagnetic waves back to x-polarized electromagnetic waves, and can absorb y-polarized electromagnetic waves, transmitting them through a metal via 7 to a circularly polarized reconfigurable transmissive patch for radiation. The reconfigurable circularly polarized transmissive patch has a 1-bit phase resolution, enabling phase shifts of 0 degrees and 180 degrees to achieve autonomous beam deflection. The reconfigurable transmissive-reflective metasurface unit is arranged into a 16×16 circularly polarized array. The antenna operates in the 10.0 GHz–12.0 GHz frequency band, reflecting x-polarized electromagnetic waves back to x-polarized electromagnetic waves and transmitting y-polarized electromagnetic waves back to circularly polarized electromagnetic waves, which can simultaneously achieve autonomous beam deflection.

[0053] Figure 3 The diagram illustrates the transmission amplitude and phase changes of two states under y-polarized incident light. It verifies that a stable 180-degree phase difference exists between the two states while maintaining a transmission amplitude above -2dB (transmittance above 80%). This demonstrates that both high transmittance and a stable 1-bit phase state can be guaranteed within the operating frequency band.

[0054] The metasurface units are configured as a 16×16 array with a focal diameter ratio of 0.6 and a center frequency of 11.0 GHz. Figure 4 , Figure 5 , Figure 6 and Figure 7 Normalized directional patterns in polar coordinate systems with array scanning angles of 0 degrees, 10 degrees, 20 degrees, and 30 degrees are shown respectively.

[0055] In one embodiment of the present invention, please refer to Figure 1 and Figure 2 The first dielectric substrate 2 is composed of Rogers RT5880 with a thickness of 3.2 mm;

[0056] The second metal patch 3 is a square metal patch with a side length of 10.6 mm and a circular metal hole with a radius of 0.8 mm in the center.

[0057] The second dielectric substrate 4 is composed of Rogers RO4450F with a thickness of 0.2 mm;

[0058] The third dielectric substrate 5 is composed of Rogers RT5880 with a thickness of 3.2 mm;

[0059] The first PIN diode 8 is used to connect the fifth metal patch 11 and the sixth metal patch 12;

[0060] The second PIN diode 9 is used to connect the fourth metal patch 10 and the fifth metal patch 11;

[0061] The fourth metal patch 10 is part of the first metal patch 1, and consists of two rectangular patches and a flag-shaped patch, and is centrally symmetrical with the sixth metal patch 12.

[0062] The fifth metal patch 11 is part of the first metal patch 1, located at the center, and consists of a square patch and two rectangular patches;

[0063] The sixth metal patch 12 is part of the first metal patch 1 and is centrally symmetrical with the fourth metal patch 10.

[0064] In this embodiment, the antenna has two states: state 0 and state 1. When the first PIN diode 8 is turned on and the second PIN diode 9 is turned off, it is state 0 of the antenna; when the first PIN diode 8 is turned off and the second PIN diode 9 is turned on, it is state 1 of the antenna.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circularly polarized coded antenna with flexibly adjustable beam, characterized in that, It includes an array composed of multiple metasurface units arranged in a periodic manner. The metasurface units include a first metal patch (1), a first dielectric substrate (2), a second metal patch (3), a second dielectric substrate (4), a third dielectric substrate (5), and a third metal patch (6) stacked from top to bottom. It also includes a metal through hole (7) penetrating the second metal patch (3), the metal through hole (7) connecting the first metal patch (1) and the third metal patch (6). The first metal patch (1) includes a fifth metal patch (11), a fourth metal patch (10) and a sixth metal patch (12) that are symmetrical to the fifth metal patch (11). A second PIN diode (9) is loaded between the fourth metal patch (10) and the fifth metal patch (11), and a first PIN diode (8) is loaded between the fifth metal patch (11) and the sixth metal patch (12). The third metal patch (6) comprises two rectangular metal patches arranged in a centrally symmetrical manner for reflecting x-polarized incident waves and absorbing the energy of y-polarized incident waves.

2. The circularly polarized coded antenna with flexibly adjustable beam as described in claim 1, characterized in that, By controlling the on / off states of the first PIN diode (8) and the second PIN diode (9), the antenna can be made to operate in two phase states: When the first PIN diode (8) is turned on and the second PIN diode (9) is turned off, the unit is in state 0; When the first PIN diode (8) is off and the second PIN diode (9) is on, the unit is in state 1; The transmission phases corresponding to the 0 state and the 1 state are 180° apart to achieve 1-bit phase resolution.

3. The circularly polarized coded antenna with flexibly adjustable beam as described in claim 1, characterized in that, The structures of the fourth metal patch (10) and the sixth metal patch (12) each include two rectangles of different sizes and a flag-shaped patch. This structure is used to excite two orthogonal modes and generate a 90° phase difference so that the transmitted wave exhibits circular polarization characteristics.

4. The circularly polarized coded antenna with flexibly adjustable beam as described in claim 1, characterized in that, The second metal patch (3) is a metal floor, and a circular isolation ring is provided in the center of the second metal patch (3). The metal through hole (7) passes through the circular isolation ring to isolate the reflection function of the third metal patch (6) from the transmission function of the first metal patch (1).

5. The circularly polarized coded antenna with flexibly adjustable beam according to claim 1, characterized in that, The antenna operates in the frequency band of 10.0 GHz to 12.0 GHz, with a center frequency of 11.0 GHz.

6. The circularly polarized coded antenna with flexibly adjustable beam according to claim 1, characterized in that, The second dielectric substrate (4) is composed of Rogers RO4450F with a thickness of 0.2 mm; Both the first dielectric substrate (2) and the third dielectric substrate (5) are composed of Rogers RT5880 with a thickness of 3.2 mm.

7. The circularly polarized coded antenna with flexibly adjustable beam according to any one of claims 1 to 6, characterized in that, The array has a size of 16 rows × 16 columns and a total of 256 metasurface units. By encoding and controlling the phase state of each metasurface unit, the deflection of the transmitted circularly polarized beam in the spatial range can be achieved.

8. The circularly polarized coded antenna with flexibly adjustable beam according to claim 4, characterized in that, The radius of the circular isolation ring is 0.8 mm.

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