Broadband multi-polarization programmable reflective array antenna

Abstract

A metasurface array comprises a plurality of electronic control metasurface units, and each electronic control metasurface unit comprises a patch layer, a first dielectric substrate layer, a floor layer, a bonding layer, a second dielectric substrate layer and a bias line layer from top to bottom; the patch layer comprises four square double-ring metal patch structures and a dipole arm structure provided with a pin diode, a central metal through hole penetrating downwards to be connected with the offset line layer is formed in the crossed position, and corresponding to the diameter of the central metal through hole, only the diameter of an opening in the floor layer is large, and the other layers are the same; a peripheral metal blind hole penetrating through the first dielectric substrate layer is downwards formed in the central point of each square double-ring metal patch structure; the bias line layer is of a fan-shaped branch knot structure; under the cooperation of the feed source antenna, the electric control metasurface unit realizes the on-off of a pin diode through phase distribution coding under the control of the direct current control circuit board and the ARDUINO microprocessor, and realizes beam scanning in a specified direction. The antenna is wide in frequency band and low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas, and in particular relates to a broadband multi-polarization programmable reflectarray antenna. Background Art

[0002] Current communication systems typically use phased array antennas for high-gain, electrically steerable antennas. While traditional phased array antenna solutions enable high-speed beam scanning and beamforming, their complex system architecture, high power consumption, and demanding control system requirements limit their widespread adoption. Traditional aperture antenna solutions, such as reflectarrays and lens antennas, offer a low-cost solution for achieving high-gain antennas. However, these antennas can only achieve adaptive beam steering through mechanical scanning, and adaptive beamforming is also difficult to implement.

[0003] Programmable reflectarray antennas, as a low-power, low-cost design option for high-gain, electrically steerable antennas, have broad application value in various radar and wireless communication applications due to their fast and flexible beam steering capabilities. Broadband programmable reflectarray antennas can be divided into two categories based on their broadband operating principles: polarization-rotating elements and multi-resonant elements. Polarization-rotating elements, because their phase control principle is frequency-independent, facilitate broadband phase quantization. Multi-resonant elements achieve multiple, similar resonant frequencies through structural design, thereby achieving a smooth, linear reflection phase curve over a wide bandwidth. Currently, most programmable reflectarray antennas have a relative bandwidth between 5% and 20%, with a few broadband programmable reflectarray antenna designs boasting relative bandwidths between 30% and 40%. However, to meet the current communications industry's demand for multifunctional antenna reuse, programmable reflectarray antennas must achieve a relative bandwidth of at least 40% to 50%. Therefore, further research is needed on broadband programmable reflectarray antennas. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a broadband multi-polarization programmable reflectarray antenna. The technical problem to be solved by the present invention is achieved through the following technical solutions: A broadband multi-polarization programmable reflectarray antenna comprises a metasurface array, a feed antenna, a DC control circuit board, and an Arduino microprocessor; the metasurface array comprises a plurality of electrically controlled metasurface units; each electrically controlled metasurface unit comprises, from top to bottom, a patch layer, a first dielectric substrate layer, a floor layer, an adhesive layer, a second dielectric substrate layer, and a bias line layer; the patch layer, the floor layer, and the bias line layer are made of metal; The patch layer is structurally symmetrical about each plane coordinate axis, and includes four square double-ring metal patch structures and a dipole arm structure connecting the center points of two diagonally opposite square double-ring metal patch structures; a PIN diode is provided on the dipole arm structure corresponding to each square double-ring metal patch structure; a central metal through-hole is provided at the intersection of the dipole arm structures, penetrating downward through each layer until it connects to the bias line layer; the diameter of the opening corresponding to the central metal through-hole on the floor layer is larger than the diameter of the central metal through-hole, and the diameter of the opening corresponding to the central metal through-hole on the remaining layers is equal to the diameter of the central metal through-hole; a surrounding metal blind hole is provided at the center point of each square double-ring metal patch structure, penetrating downward into the first dielectric substrate layer; The bias line layer adopts a fan-shaped branch structure to couple with the ground layer to generate distributed capacitance to achieve AC / DC isolation; Each electrically controlled metasurface unit uses phase distribution encoding to turn on or off the internal PIN diode under the control of the DC control circuit board and the ARDUINO microprocessor to achieve beam scanning of the target angle within the target frequency band.

[0005] Beneficial effects of the present invention: In the wide-band multi-polarization programmable reflectarray antenna provided by the embodiment of the present invention, the metasurface array includes a plurality of electrically controlled metasurface units, and the electrically controlled metasurface units adopt cross-dipole form patches, and the patch structure is designed with dual resonance and dual-polarization symmetrical structure, which can achieve 1-bit phase control and cross-polarization suppression within a wide band. The AC / DC isolation structure of the bias line layer adopts the distributed capacitance generated by the coupling of fan-shaped branches and the floor layer instead of the RF capacitor to achieve AC / DC isolation of the electrically controlled metasurface units within a wide band, while reducing the complexity and cost of the unit structure. The programmable reflectarray antenna designed by the present invention has the advantages of wide band, low cost and simple unit structure, and has broad application potential in the fields of next-generation mobile communications, satellite communications, radar detection and so on. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 A schematic structural diagram of a broadband multi-polarization programmable reflectarray antenna provided by an embodiment of the present invention; Figure 2 A schematic diagram of the three-dimensional structure of an electrically controlled metasurface unit of a broadband multi-polarization programmable reflectarray antenna provided by an embodiment of the present invention; Figure 3 Schematic diagram of the planar structure of the patch layer of the electrically controlled metasurface unit according to an embodiment of the present invention; Figure 4 Schematic diagram of the planar structure of the bias line layer of the electrically controlled metasurface unit according to an embodiment of the present invention; Figure 5aSchematic diagram of the structure of a low-frequency feed antenna according to an embodiment of the present invention; Figure 5b This is a radiation performance diagram of the low-frequency feed antenna according to an embodiment of the present invention; Figure 6a Schematic diagram of the structure of a high-frequency feed antenna according to an embodiment of the present invention; Figure 6b This is a radiation performance diagram of the high-frequency band feed antenna according to an embodiment of the present invention; Figure 7 In the experiment of the embodiment of the present invention, the beam pointing is the elevation angle =0°, azimuth =0° when the gain and aperture efficiency vary with frequency; Figure 8 In the experiment of the embodiment of the present invention, the beam pointing is =0°, =0° when the cross-polarization level changes with frequency; Figure 9 This is a reflection coefficient diagram when electromagnetic waves are incident on the electrically controlled metasurface unit at different angles in the experiment of the embodiment of the present invention. DETAILED DESCRIPTION

[0007] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0008] In recent years, programmable reflectarray antennas have attracted widespread attention due to their beam agility. However, research on the broadband performance of programmable reflectarray antennas has yet to achieve breakthroughs. To address the narrow bandwidth of programmable reflectarray antennas, embodiments of the present invention provide a broadband multi-polarization programmable reflectarray antenna, comprising: A metasurface array, a feed antenna, a DC control circuit board, and an ARDUINO microprocessor; the metasurface array includes a plurality of electrically controlled metasurface units; The structure of the metasurface array can be found in Figure 1 As shown, the metasurface array in the embodiment of the present invention contains M N electrically controlled metasurface units, wherein M and N are both natural numbers greater than 0, and M and N may be the same or different. Figure 1 China 12 Take 12 electrically controlled metasurface units as an example. Of course, the embodiments of the present invention are not limited to this.

[0009] To understand the structure of the electrically controlled metasurface unit more clearly, see Figure 2 The three-dimensional structure diagram of the electrically controlled metasurface unit shown in FIG. Figure 3 Schematic diagram of the planar structure of the patch layer of the electrically controlled metasurface unit shown.

[0010] The embodiment of the present invention is designed to obtain a broadband 1-bit electrically controlled metasurface unit. The “broadband” refers to the system’s ability to maintain stable beam scanning performance within a wide continuous frequency range (e.g., 13 GHz to 20 GHz); and the “1-bit” phase control refers to controlling the conduction and disconnection of the PIN diode in the electrically controlled metasurface unit so that the unit’s reflection phase of the electromagnetic wave presents two discrete states (with a phase difference of 180°), thereby realizing digital control of the beam direction. The essence of “1-bit” is to simplify the continuous electromagnetic wave phase information into “0” and “1” in binary logic, which can be understood in conjunction with the description below.

[0011] For details, see Figure 2 Each electrically controlled metasurface unit includes, from top to bottom, a patch layer, a first dielectric substrate layer, a floor layer, an adhesive layer, a second dielectric substrate layer, and a bias line layer; the patch layer, the floor layer, and the bias line layer are made of metal, which may be copper; the adhesive layer is used to press the two dielectric substrate layers together.

[0012] The models and specific material parameters of the first dielectric substrate layer, the second dielectric substrate layer, and the adhesive layer can be selected as needed. In a preferred embodiment, the models of the first dielectric substrate layer and the second dielectric substrate layer are F4BME265, and the relative dielectric constant ( ) is 2.65, the loss tangent value ( ) is 0.0013; The adhesive layer has a model of WL-PP300, a relative dielectric constant of 3.00, and a loss tangent of 0.0028; The metal structure of the patch layer in the embodiment of the present invention is a double-ring cross dipole form nested inside and outside. Figure 3 It is understood that the patch layer is structurally symmetrical about each plane coordinate axis, wherein the each plane coordinate axis includes an x-axis, a y-axis, a u-axis and a v-axis; wherein the x-axis and the y-axis are perpendicular to each other, forming an xy coordinate system; the u-axis and the v-axis are perpendicular to each other, forming a uv coordinate system; the uv coordinate system is obtained by rotating the xy coordinate system plane by 45°.

[0013] The patch layer includes four square double-ring metal patch structures and a dipole arm structure connecting the center points of two square double-ring metal patch structures in a diagonal direction; a PIN diode is provided on the dipole arm structure corresponding to each square double-ring metal patch structure; That is to say, two PIN diodes are loaded in the u-axis and v-axis directions respectively; for each PIN diode, the PIN diode connects the square double-ring metal patch structure and the dipole arm structure, and can be located in the middle position between the center point of the square double-ring metal patch structure and the intersection of the dipole arm structure; the PIN diodes in each electrically controlled metasurface unit adopt the same model, for example, these four PIN diodes can adopt MACOM brand PIN diodes, and the model code can be MADP-000907-14020P.

[0014] The dipole arm structure cross position is provided with a central metal via that penetrates each layer downward until it connects to the bias line layer. Figure 2 It can be understood that the central metal through-hole will penetrate the first dielectric substrate layer, the floor layer, the adhesive layer, and the second dielectric substrate layer. Therefore, corresponding holes will be opened on these layers, which can all be circular holes. The diameter of the hole corresponding to the central metal through-hole on the floor layer is larger than the diameter of the central metal through-hole, which is used to isolate the central metal through-hole from the floor layer. The diameter of the holes corresponding to the central metal through-hole on the remaining layers is equal to the diameter of the central metal through-hole; and a surrounding metal blind hole is provided at the center point of each square double-ring metal patch structure, which penetrates downward into the first dielectric substrate layer. The surrounding metal blind holes do not penetrate the remaining layers below the first dielectric substrate layer, but will contact the floor layer.

[0015] In an embodiment of the present invention, the electrically controlled metasurface unit uses a cross-dipole patch, and the patch structure is designed with a dual-resonance design and a dual-polarization symmetric structure, which can achieve 1-bit phase control and cross-polarization suppression within a wide bandwidth. It can be understood by those skilled in the art that, in the metasurface unit, the dual-resonance design refers to optimizing the geometric structure of the cross-dipole patch (such as length, width, spacing, etc.) so that the unit resonates at two different frequency points. The core purpose of this design is to broaden the operating bandwidth of the metasurface. Dual polarization means that the metasurface unit can simultaneously respond to or control two orthogonal polarization directions; the symmetric structure ensures that the performance of the two polarization modes is consistent. Cross-polarization suppression refers to the technical ability to minimize the non-target polarization direction component (cross-polarization component) and only retain or enhance the target polarization direction component (co-polarization component) during the transmission, reflection or control of electromagnetic waves. For example, if the goal is to transmit "vertically polarized" electromagnetic waves, the "horizontally polarized" component needs to be suppressed so that the output signal contains almost only vertical polarization components.

[0016] Through dual-resonance design and dual-polarization symmetrical structure design, the present invention achieves good 1-bit phase quantization performance and cross-polarization suppression when the electromagnetic wave is u-polarized and vertically incident. By superimposing two resonant frequencies, the 180° phase difference between co-polarization and cross-polarization is locked within a wide bandwidth, ensuring that the suppression effect does not decay with frequency. The "cross-dipole patch" is used to make the response characteristics of the metasurface unit to the two orthogonal polarization directions (i.e., u-polarization and v-polarization) consistent, avoiding energy leakage in the cross-polarization direction due to structural asymmetry.

[0017] See also Figure 4 The bias line layer uses a fan-shaped branch structure to couple with the ground layer to generate distributed capacitance for AC / DC isolation, preventing RF current from flowing into the bias line layer. The rectangular microstrip line in the fan-shaped branch structure serves as the DC bias line, while the circular portion contacts the central metal via.

[0018] In this embodiment of the present invention, one end of each PIN diode is connected to the DC bias line of the bias line layer through the central metal via, and the other end is connected to the floor layer through the surrounding metal blind vias. The DC bias line is connected to the positive electrode of an external DC source, and the floor layer is connected to the negative electrode of the DC source. When the DC source outputs a high level, the PIN diode is turned on; when the DC source outputs a low level, the PIN diode is turned off. PIN diodes within the same electrically controlled metasurface unit are turned on or off simultaneously.

[0019] Each electrically controlled metasurface unit uses phase distribution encoding to turn on or off the internal PIN diode under the control of the DC control circuit board and the ARDUINO microprocessor to achieve beam scanning of the target angle within the target frequency band.

[0020] As a preferred embodiment, the structural parameters of the electrically controlled metasurface unit are designed as follows: The thickness of the first dielectric substrate layer 2mm; the thickness of the floor layer The thickness of the adhesive layer is 0.035 mm; The thickness of the second dielectric substrate layer is 0.1 mm. The electrically controlled metasurface unit is a square with a side length of 7.5mm; In the patch layer, any square double-ring metal patch structure includes a square outer ring and a square inner patch nested in the square outer ring; wherein the outer side length of the square outer ring is 2.4mm, the inner side length of the square outer ring The side length of the patch in the square is 2mm 1mm; the diameter of the central metal through hole and the surrounding metal blind holes 0.4mm; the spacing between adjacent square double-ring metal patch structures 1mm; the width of the dipole arm structure 0.5mm; the gap width between the pin diode pads 0.3mm; cutting angle 1mm; among them, the cutting angle Indicates the length of the corner of the patch cut off in the square. For details, please refer to the relevant technical understanding in this field.

[0021] The diameter of the hole opened on the floor layer corresponding to the central metal through hole is 0.8 mm; The radius of the through-hole pad in the bias line layer that contacts the central metal through-hole is The width of the DC bias line of the bias line layer is 0.8 mm. The radius of the fan-shaped branches is 0.3mm 2.5mm.

[0022] For ease of understanding, the above parameters are collectively displayed in Table 1.

[0023] Table 1 Structural parameters of electrically controlled metasurface units

[0024] When the wideband multi-polarization programmable reflectarray antenna of the embodiment of the present invention is used, the target frequency band may include a range of 13-20 GHz. Those skilled in the art will appreciate that the 13-20 GHz frequency band belongs to the super high frequency (SHF) frequency band, which has a frequency range of 3-30 GHz. Of course, the target frequency band of the embodiment of the present invention is not limited to 13-20 GHz, and the provided wideband multi-polarization programmable reflectarray antenna can be fine-tuned according to the corresponding target frequency band.

[0025] The embodiments of the present invention can achieve two-dimensional beam scanning within a 60° range within the target frequency band. During use, the metasurface array can be placed vertically using a bracket or other equipment, with the feed antenna positioned directly in front of the metasurface array, facing the metasurface array's patch layer. The DC control circuit board and Arduino microprocessor are positioned behind the metasurface array, wherein the DC control circuit board and the Arduino microprocessor are communicatively connected and connected to the electrically controlled metasurface unit of the metasurface array.

[0026] Considering the operating frequency band of the metasurface array, the feed antennas of the present invention are divided into two types: high-frequency and low-frequency bands, which are used to verify the broadband performance of the metasurface array. In other words, the feed antennas include low-frequency feed antennas and high-frequency feed antennas.

[0027] The feed antenna of the embodiment of the present invention can adopt any broadband antenna, such as a broadband horn antenna, a Vivaldi antenna feed antenna, etc. During the experiment of the present invention, any feed antenna type can be selected to design a low-frequency feed antenna and a high-frequency feed antenna to cope with broadband scenarios. In an optional embodiment, the low-frequency feed antenna and the high-frequency feed antenna can adopt a pyramidal horn antenna.

[0028] The embodiment of the present invention is directed to a pyramidal horn antenna and specifically designs a low-frequency-band feed antenna and a high-frequency-band feed antenna.

[0029] See Figure 5a The structural diagram of the low-frequency band feed antenna shown in FIG. Figure 5b The radiation performance diagram of the low-frequency feed antenna shown in the figure is that the waveguide section of the low-frequency feed antenna adopts the international standard waveguide size WR-75, the flange model is FDP120, and the size of the horn angle part is 37.05mm 27.53 mm 18mm; the physical waveguide part adopts a waveguide coaxial conversion structure (such as Hengda Microwave's HD-120WCAS), and the horn angle part is made of aluminum alloy material 3D printing technology.

[0030] See Figure 6a The structural diagram of the high frequency band feed antenna shown in FIG. Figure 6b The radiation performance diagram of the high-frequency feed antenna shown in the figure is as follows. The waveguide section of the high-frequency feed antenna adopts the international standard waveguide size WR-51, the flange model is FDP180, and the size of the horn angle part is 28.95mm. 22.48 mm 16mm; the physical waveguide part adopts a waveguide coaxial conversion structure (such as Hengda Microwave's HD-180WCAS), and the horn angle part is made of aluminum alloy material 3D printing technology.

[0031] With 12 Taking 12 electrically controlled metasurface units as an example, the overall size of the prototype of the broadband multi-polarization programmable reflectarray antenna of the embodiment of the present invention is 215mm 235mm 300mm, the distance from the feed antenna to the surface of the metasurface array is 85mm (focal diameter ratio is 0.94). There are 12 2 Six pins connect the metasurface array to the DC control circuit board. The brackets securing the metasurface array and feed antenna are fabricated using fused deposition modeling (3D printing) of ABS engineering plastic. The metasurface array is manufactured using PCB technology, and lumped components such as PIN diodes and resistors are soldered using SMT (Surface Mounted Technology). To facilitate soldering and minimize reflection losses from the metasurface, the solder mask only covers the periphery of the pads.

[0032] The DC control circuit board includes 72 8-bit shift register chips (model SN74HC164DR). Considering the operating voltage limits of the shift register chips, the output of each shift register chip controls the on / off state of eight PIN diodes in two electrically controlled metasurface units via pin headers and cables. An 80Ω resistor is connected in series with the output of each shift register chip to ensure that the current in each PIN diode is around 15mA. Ultimately, an external Arduino microprocessor is used to achieve parallel control of all PIN diodes in the metasurface array.

[0033] Specifically, the working process of the broadband multi-polarization programmable reflectarray antenna to achieve beam scanning at a target angle within a target frequency band includes the following steps: Step a1: Calculate the compensation phase of each electrically controlled metasurface unit using a first preset formula according to the corresponding operating frequency band in the target frequency band and the acquired target angle; Taking the 13-20 GHz band as an example, during the experimental design of the antenna, the wideband multi-polarization programmable reflectarray antenna employed segmented coding to balance the beamsteering coding requirements of different frequency bands and minimize in-band gain attenuation, taking into account its operating bandwidth. The entire 13-20 GHz band was divided into three operating bands, with 14 GHz, 17 GHz, and 20 GHz used as the phase distribution calculation frequencies for each band, verifying that the metasurface antenna could meet performance requirements within this bandwidth.

[0034] After the design is completed, when the wideband multi-polarization programmable reflectarray antenna of the present invention is actually used, the operating frequency band may be a section of the target frequency band 13-20 GHz. Then, based on the operating frequency band and the obtained target angle, the compensation phase of each electrically controlled metasurface unit is calculated using the first preset formula, and based on the high or low frequency band, a low-frequency band feed antenna or a high-frequency band feed antenna is selected.

[0035] When the broadband multi-polarization programmable reflectarray antenna realizes the beam scanning function, the compensation phase of the electrically controlled metasurface unit satisfies the first preset formula.

[0036] The first preset formula is expressed as: ; in, Indicates the The compensation phase of the electrically controlled metasurface unit, is the number of the electrically controlled metasurface unit, ranging from 1 to 144; is the free space wave number, , is the free space wavelength, which is calculated based on the center frequency of the operating frequency band; Indicates the phase center of the feed antenna to the The spatial distance between the electrically controlled metasurface units is taken as the coordinate origin, with the center of the metasurface array as the coordinate origin. The position vector of the electrically controlled metasurface unit is , can be detected; the unit vector specifying the beam direction is , Indicates the azimuth angle, which can be any value between 0° and 360°; Indicates the elevation angle, the value is the target angle; is the reference phase introduced; For example, for the first divided working frequency band, its phase distribution calculation frequency is 14GHz. If the target angle is 30°, for each electrically controlled metasurface unit, and Known, then use 14GHz to calculate , expressed as , is the wave speed, , thereby calculating the compensation phase of the electrically controlled metasurface unit. Similarly, the compensation phase of each electrically controlled metasurface unit can be calculated.

[0037] Step a2: for each electrically controlled metasurface unit, determine the working state of the electrically controlled metasurface unit using a second preset formula; wherein the working state includes state0 or state1; The second preset formula is expressed as: .

[0038] For each electrically controlled metasurface unit, the compensation phase thereof is judged using the second preset formula to determine whether the working state of the electrically controlled metasurface unit is state0 or state1, thereby quantifying the spatial phase into the working state.

[0039] Step a3, according to the working state of each electrically controlled metasurface unit, using 01 coding to perform phase distribution coding on all electrically controlled metasurface units, and outputting the coding results to the ARDUINO microprocessor, wherein the state0 state code is 0 and the state1 state code is 1; Steps a1 to a3 can be completed by a software program, for example, by loading a MATLAB program on a computer.

[0040] Therefore, the working state of each electrically controlled metasurface unit is encoded as 0 or 1, and the working states of all electrically controlled metasurface units can be represented by a 01 coding sequence in a certain order, and this 01 coding sequence is sent to the ARDUINO microprocessor as the coding result.

[0041] In step a4, the ARDUINO microprocessor controls the 8-bit shift register chip in the DC control circuit board according to the encoding result, and outputs a high level or a low level to the connected electrically controlled metasurface unit to control the PIN diode inside the electrically controlled metasurface unit to be turned on or off; wherein, the output port of each 8-bit shift register chip controls the on-off state of all PIN diodes in the two electrically controlled metasurface units through pin headers and cables.

[0042] When the pin diode is turned on, it corresponds to the state1 state, and when the pin diode is turned off, it corresponds to the state0 state.

[0043] The experimental process proves that the embodiment of the present invention uses the working form of segment coding to select the frequency The phase distribution of each working frequency band is calculated by the above-mentioned first preset formula and second preset formula. The obtained phase distribution information is coded in 01 form through the DC control board to regulate the state of each electrically controlled metasurface unit on the metasurface array, so that the metasurface array presents the desired phase distribution. The beam pattern corresponding to the radiation of the wide-band multi-polarization programmable reflectarray antenna can realize beam scanning within 13-20GHz.

[0044] In the wide-band multi-polarization programmable reflectarray antenna provided by the embodiment of the present invention, the metasurface array includes a plurality of electrically controlled metasurface units, and the electrically controlled metasurface units adopt cross-dipole form patches, and the patch structure is designed with dual resonance and dual-polarization symmetrical structure, which can achieve 1-bit phase control and cross-polarization suppression within a wide band. The AC / DC isolation structure of the bias line layer adopts the distributed capacitance generated by the coupling of fan-shaped branches and the floor layer instead of the RF capacitor to achieve AC / DC isolation of the electrically controlled metasurface units within a wide band, while reducing the complexity and cost of the unit structure. The programmable reflectarray antenna designed by the present invention has the advantages of wide band, low cost and simple unit structure, and has broad application potential in the fields of next-generation mobile communications, satellite communications, radar detection and so on.

[0045] To facilitate understanding of the effects of the broadband multi-polarization programmable reflectarray antenna provided by the present invention, relevant comparisons and experimental proofs are given below.

[0046] 1. Comparison with a Ka-band broadband reconfigurable reflector unit and array antenna (CN 114256629 A); This patent designs a broadband reconfigurable reflection unit and array antenna with a relative bandwidth of 25%; within the range of 31GHz-40GHz, it can achieve ±50° beam scanning in two-dimensional space.

[0047] Based on the dual-resonance structure and multi-polarization control principle, the present invention adopts a broadband electrically controlled metasurface unit and realizes a multi-polarization (linear polarization / circular polarization) broadband programmable reflectarray antenna through a dual-resonance patch coupling design. It can achieve two-dimensional beam scanning within a range of 60° in the frequency band of 13-20GHz. Specifically, the dual-resonance structure increases the 3-dB gain bandwidth to 55.6% (13-23GHz), covering a continuous ultra-wide frequency band. The simulated cross-polarization level is <-32dB, and the tested level is <-19.47dB (the patent does not provide specific values), which significantly suppresses cross-polarization interference. By analyzing the reflection coefficient at different incident angles, the stability of the reflection characteristics within the 30° oblique incidence range is verified.

[0048] 2. Comparison with a circularly polarized decoupled reconfigurable reflectarray antenna based on a metasurface (CN120073334A); This patent designs a metasurface-based circularly polarized decoupled reconfigurable reflectarray antenna, achieving 1-bit phase reconfiguration in the 6.9-7.5 GHz range (relative bandwidth of approximately 8.1%). However, this design only supports circular polarization (left-hand / right-hand) and cannot cover linear polarization scenarios. The operating frequency band is narrow (relative bandwidth is only 8.1%), making it difficult to meet broadband communication requirements. The cross-polarization level is <-15 dB, which only meets low axial ratio requirements and has limited interference suppression capabilities.

[0049] Based on the dual-resonance structure and multi-polarization control principles, this invention uses a broadband electrically controlled metasurface unit and, through a dual-resonance patch coupling design, realizes a broadband programmable reflectarray antenna that operates in linear / circular polarization multi-polarization. Specifically, the dual-resonance structure increases the 3-dB gain bandwidth to 55.6% (13-23 GHz, a relative bandwidth 6.8 times that of the patented antenna), covering a continuous ultra-wide frequency band. The simulated cross-polarization level is <-32 dB (tested <-19.47 dB), significantly better than the <-15 dB of the patented antenna. By analyzing the reflection coefficient at different incident angles, the stability of the reflection characteristics within a 30° oblique incidence range was verified.

[0050] The present invention solves the shortcomings of the patent in polarization type coverage (circular polarization only), bandwidth coverage (relatively insufficient bandwidth), cross-polarization suppression (low level) and oblique incidence stability (unverified) through multi-polarization control and wide-band dual-resonance structure, providing a solution for wide-band and high-speed beam control that adapts to the needs of multiple scenarios.

[0051] 3. Comparison with a broadband reconfigurable reflective metasurface antenna (CN 115051150 A); This patent designs a broadband reconfigurable reflective metasurface antenna with a 3-dB operating bandwidth of 9.4-11 GHz and a beam scanning range of ±50°. However, this design only supports linear polarization and cannot cover circular polarization scenarios, and the unit structure is complex. The present invention is based on the principle of wide-band multi-polarization programmable reflectarray and adopts a simpler electrically controlled metasurface unit structure to achieve multi-polarization operation with switching between linear polarization and circular polarization and an ultra-wideband of 13 to 23 GHz (3-dB gain bandwidth), thus solving the problems of the patent in terms of single polarization dimension, insufficient bandwidth and complex structure.

[0052] Table 2 below shows a comparison of the present invention with other similar technologies. First, compared to existing broadband operation with single linear or circular polarization, the present invention achieves a broadband programmable reflectarray antenna capable of multi-polarization operation. Second, the dual-resonance structure employed in the present invention achieves a 3-dB gain bandwidth of 55.6%, exceeding the relative bandwidth of existing antennas of the same type.

[0053] Table 2 Comparison of the present invention with other similar technologies

[0054] Reference technology 1 is Luyen H, Zhang Z, Booske JH, et al. Wideband, Beam-Steerable Reflectarrays Based on Minimum-Switch Topology, Polarization-Rotating Unit Cells[J]. IEEE Access, 2019, 7: 36568-36578. Reference technology 2 is Wu F, Lu R, Wang J, et al. Circularly Polarized One-BitReconfigurable ME-Dipole Reflectarray at X-Band[J]. IEEE Antennas andWireless Propagation Letters, 2022, 21(3): 496-500; Reference technology 3 is Zhou SG, Zhao G, Xu H, et al. A Wideband 1-Bit Reconfigurable Reflectarray Antenna at Ku-Band[J]. IEEE Antennas and Wireless Propagation Letters, 2022, 21(3): 566-570; Reference technology 4 is Xiang BJ, Dai X, Luk K M. A Wideband Low-Cost Reconfigurable Reflectarray Antenna With 1-Bit Resolution[J]. IEEE Transactions on Antennas and Propagation, 2022, 70(9): 7439-7447.

[0055] See Figure 7 and Figure 8 , Figure 7 is the beam pointing elevation angle =0°, azimuth =0° when the gain and aperture efficiency vary with frequency, Figure 8 The beam pointing =0°, =0° when the cross-polarization level changes with frequency.

[0056] Figure 7 and Figure 8 Simulation results show a maximum aperture efficiency of 23.9%, a 3-dB gain bandwidth of 55.6%, an operating frequency band of 13 to 23 GHz, and a cross-polarization level of less than -32 dB across the entire frequency band. Test results show a maximum aperture efficiency of 17.7%, a 3-dB gain bandwidth of 55.6%, an operating frequency band of 13 to 23 GHz, and a cross-polarization level of less than -19.47 dB across the entire frequency band. The designed broadband multi-polarization programmable reflectarray antenna provides a new design solution for achieving high-speed beam steering over a wide frequency band, offering the advantages of wide bandwidth, flexible beam switching, and low cost.

[0057] Given that the electromagnetic waves radiated by the feed source will be incident on the electrically controlled metasurface at different angles, the reflection coefficients of "state1" and "state0" within the working frequency band are analyzed as a function of the incident angle. The reflection coefficients of electromagnetic waves incident at different angles on the broadband 1-bit electrically controlled metasurface unit are shown in the following figure. Figure 9 The results show that the reflection characteristics of the broadband electrically controlled metasurface remain stable within the 30° oblique incident angle range.

[0058] It should be noted that, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0060] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A broadband multi-polarization programmable reflectarray antenna, characterized in that: The invention comprises a metasurface array, a feed antenna, a DC control circuit board, and an ARDUINO microprocessor; the metasurface array comprises a plurality of electrically controlled metasurface units; each electrically controlled metasurface unit comprises, from top to bottom, a patch layer, a first dielectric substrate layer, a floor layer, an adhesive layer, a second dielectric substrate layer, and a bias line layer; the patch layer, the floor layer, and the bias line layer are made of metal; The patch layer is structurally symmetrical about each plane coordinate axis, and includes four square double-ring metal patch structures and a dipole arm structure connecting the center points of two diagonally opposite square double-ring metal patch structures; a PIN diode is provided on the dipole arm structure corresponding to each square double-ring metal patch structure; a central metal through-hole is provided at the intersection of the dipole arm structures, penetrating downward through each layer until it connects to the bias line layer; the diameter of the opening corresponding to the central metal through-hole on the floor layer is larger than the diameter of the central metal through-hole, and the diameter of the opening corresponding to the central metal through-hole on the remaining layers is equal to the diameter of the central metal through-hole; a surrounding metal blind hole is provided at the center point of each square double-ring metal patch structure, penetrating downward into the first dielectric substrate layer; The bias line layer adopts a fan-shaped branch structure to couple with the ground layer to generate distributed capacitance to achieve AC / DC isolation; Each electrically controlled metasurface unit uses phase distribution encoding to turn on or off the internal PIN diode under the control of the DC control circuit board and the ARDUINO microprocessor to achieve beam scanning of the target angle within the target frequency band.

2. The broadband multi-polarization programmable reflectarray antenna according to claim 1, wherein: One end of any PIN diode is connected to the DC bias line of the bias line layer through the central metal through-hole, and the other end is connected to the floor layer through the surrounding metal blind holes; the DC bias line is connected to the positive electrode of the external DC source, and the floor layer is connected to the negative electrode of the DC source.

3. The broadband multi-polarization programmable reflectarray antenna according to claim 1, wherein: The plane coordinate axes include an x-axis, a y-axis, a u-axis, and a v-axis; wherein the x-axis and the y-axis are perpendicular to each other, forming an xy coordinate system; the u-axis and the v-axis are perpendicular to each other, forming a uv coordinate system; the uv coordinate system is obtained by rotating the xy coordinate system plane by 45°.

4. The broadband multi-polarization programmable reflectarray antenna according to claim 1 or 2, characterized in that: The thickness of the first dielectric substrate layer 2mm; the thickness of the floor layer The thickness of the adhesive layer is 0.035 mm; The thickness of the second dielectric substrate layer is 0.1 mm. The electrically controlled metasurface unit is a square with a side length of 7.5mm; In the patch layer, any square double-ring metal patch structure includes a square outer ring and a square inner patch nested in the square outer ring; wherein the outer side length of the square outer ring is 2.4mm, the inner side length of the square outer ring The side length of the patch in the square is 2mm 1mm; the diameter of the central metal through hole and the surrounding metal blind holes 0.4mm; the spacing between adjacent square double-ring metal patch structures 1mm; the width of the dipole arm structure 0.5mm; the gap width between the pin diode pads 0.3mm; cutting angle 1mm; The diameter of the hole opened on the floor layer corresponding to the central metal through hole is 0.8 mm; The radius of the through-hole pad in the bias line layer that contacts the central metal through-hole is The width of the DC bias line of the bias line layer is 0.8 mm. The radius of the fan-shaped branches is 0.3mm 2.5mm.

5. The broadband multi-polarization programmable reflectarray antenna according to claim 1, wherein: The model of the first dielectric substrate layer and the second dielectric substrate layer is F4BME265, with a relative dielectric constant of 2.65 and a loss tangent of 0.0013; The adhesive layer has a model of WL-PP300, a relative dielectric constant of 3.00, and a loss tangent of 0.0028; The PIN diodes in each electrically controlled metasurface unit are of the same model.

6. The broadband multi-polarization programmable reflectarray antenna according to claim 1, wherein: The feed antenna includes a low-frequency band feed antenna and a high-frequency band feed antenna.

7. The broadband multi-polarization programmable reflectarray antenna according to claim 6, wherein: The low-frequency band feed antenna and the high-frequency band feed antenna adopt pyramidal horn antennas; wherein, the waveguide section of the low-frequency band feed antenna adopts the international standard waveguide size WR-75, the flange model is FDP120, and the size of the horn angle part is 37.05mm 27.53mm 18mm; the waveguide section of the high-frequency feed antenna adopts the international standard waveguide size WR-51, the flange model is FDP180, and the size of the horn angle part is 28.95mm 22.48mm 16mm; The physical waveguide parts of the low-frequency band feed antenna and the high-frequency band feed antenna adopt a waveguide coaxial conversion structure, and the horn angle part is made of aluminum alloy material 3D printing technology.

8. The broadband multi-polarization programmable reflectarray antenna according to claim 1, wherein: The working process of the broadband multi-polarization programmable reflectarray antenna to achieve beam scanning at a target angle within a target frequency band includes: Calculating the compensation phase of each electrically controlled metasurface unit using a first preset formula according to the corresponding operating frequency band in the target frequency band and the acquired target angle; For each electrically controlled metasurface unit, determining the operating state of the electrically controlled metasurface unit using a second preset formula; wherein the operating state includes a state0 state or a state1 state; According to the working state of each electrically controlled metasurface unit, a 01 encoding method is used to perform phase distribution encoding on all electrically controlled metasurface units, and the encoding result is output to the ARDUINO microprocessor, wherein the state0 state is encoded as 0 and the state1 state is encoded as 1; The ARDUINO microprocessor controls the 8-bit shift register chip in the DC control circuit board according to the encoding result, and outputs a high level or a low level to the connected electrically controlled metasurface unit to control the PIN diode inside the electrically controlled metasurface unit to be turned on or off; wherein, the output port of each 8-bit shift register chip controls the on-off state of all PIN diodes in the two electrically controlled metasurface units through pin headers and cables.

9. The broadband multi-polarization programmable reflectarray antenna according to claim 8, characterized in that: The first preset formula is expressed as: ； in, Indicates the The compensation phase of the electrically controlled metasurface unit; is the free space wave number, , is the free space wavelength, which is calculated based on the center frequency of the operating frequency band; Indicates the phase center of the feed antenna to the The spatial distance between the electrically controlled metasurface units is taken as the coordinate origin, with the center of the metasurface array as the coordinate origin. The position vector of the electrically controlled metasurface unit is ; The unit vector specifying the beam direction is , Indicates the azimuth angle, which can be any value between 0° and 360°; Indicates the elevation angle, the value is the target angle; is the reference phase introduced; The second preset formula is expressed as: 。 10. The broadband multi-polarization programmable reflectarray antenna according to any one of claims 1, 8, and 9, wherein: The target frequency band ranges from 13 to 20 GHz.

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