A broadband multi-polarization programmable reflectarray antenna

Abstract

The application discloses a broadband multi-polarization programmable reflective array antenna, wherein a metasurface array comprises a plurality of electrically controlled metasurface units, from top to bottom, including a patch layer, a first dielectric substrate layer, a ground plate layer, an adhesive layer, a second dielectric substrate layer and a bias line layer; the patch layer comprises four square double-ring metal patch structures and dipole arm structures provided with pin diodes, a central metal through hole penetrating downward to the bias line layer is arranged at a crossing position, and only the ground plate layer has a larger hole diameter corresponding to the diameter, and the remaining layers are the same; each square double-ring metal patch structure has a surrounding metal blind hole penetrating downward through the first dielectric substrate layer at a center point; the bias line layer is a fan-shaped branch structure; under cooperation of a feed source antenna, the electrically controlled metasurface unit is phase-distributed coded, pin diode on-off is realized under control of a direct current control circuit board and an ARDUINO microprocessor, and beam scanning in a specified direction is realized. The antenna disclosed by the application has a wide frequency band and low cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antennas, and particularly relates to a wideband multi-polarization programmable reflective array antenna. BACKGROUND

[0002] The high-gain electrically steerable antenna in the current communication system usually adopts a phased array antenna, however, the traditional phased array antenna scheme, although being capable of realizing high-speed beam scanning and beam shaping, is limited in large-scale application due to a complex system architecture, high power consumption and high requirements on a control system. The traditional aperture antenna scheme such as a reflective array antenna and a lens antenna provides a low-cost solution for realizing a high-gain antenna. However, such an antenna can only realize adaptive beam control through mechanical scanning, and it is also difficult to realize adaptive beam shaping.

[0003] The programmable reflective array antenna, as a low-power and low-cost design scheme in the high-gain electrically steerable antenna, has wide application value in various radar and wireless communication applications due to its fast and flexible beam regulation and control capability. The wideband programmable reflective array antenna can be divided into two categories according to the wideband working principle, the first category is a polarization rotation type unit, and the second category is a multi-resonance type unit. The polarization rotation type unit is relatively easy to realize wideband phase quantization because its phase regulation principle is independent of frequency. The multi-resonance unit realizes multiple resonant frequencies through structural design, so as to realize a smooth linear reflection phase curve in a wideband range. At present, the relative bandwidth of most programmable reflective array antennas is between 5% and 20%, and the relative bandwidth of a few wideband programmable reflective array antennas is between 30% and 40%. However, to meet the requirements of the current communication industry on antenna multi-function multiplexing, the relative bandwidth of the programmable reflective array antenna needs to reach at least 40% to 50%, so the wideband programmable reflective array antenna still needs further research. SUMMARY

[0004] In order to solve the above problems in the prior art, the application provides a wideband multi-polarization programmable reflective array antenna. The technical problem to be solved by the application is solved through the following technical scheme.

[0005] A wideband multi-polarization programmable reflective array antenna, comprising a metasurface array, a feed antenna, a direct current 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 ground plate layer, an adhesive layer, a second dielectric substrate layer and a bias line layer; the patch layer, the ground plate layer and the bias line layer are metal materials;

[0006] 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 square double-ring metal patch structures in opposite directions; a pin diode is arranged on the dipole arm structure corresponding to each square double-ring metal patch structure; a central metal through hole is arranged at the intersection position of the dipole arm structure, which penetrates through each layer to connect the bias line layer, the opening diameter of the central metal through hole on the ground plate layer is larger than the diameter of the central metal through hole, and the opening diameter of 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 arranged at the center point of each square double-ring metal patch structure to penetrate into the first dielectric substrate layer;

[0007] The bias line layer adopts a fan-shaped branch structure to be coupled with the ground plate layer to generate distributed capacitance to realize AC / DC isolation.

[0008] Each electrically controlled metasurface unit realizes the conduction or disconnection of the internal pin diode in a phase distribution coding mode under the control of the DC control circuit board and the ARDUINO microprocessor, so as to realize the beam scanning of the target angle in the target frequency band.

[0009] The beneficial effects of the present application are as follows:

[0010] In the wideband multi-polarization programmable reflectarray antenna provided by the embodiment of the present application, the metasurface array includes a plurality of electrically controlled metasurface units, the electrically controlled metasurface unit adopts a cross-dipole form patch, and the patch structure is designed for double resonance and double-polarization symmetric structure, so that 1-bit phase control and cross-polarization suppression in a wide frequency band can be realized. The AC / DC isolation structure of the bias line layer adopts a distributed capacitor generated by the coupling of a fan-shaped branch and a ground plate layer instead of a radio frequency capacitor, so as to realize the AC / DC isolation of the electrically controlled metasurface unit in a wide frequency band, and at the same time, the complexity and cost of the unit structure can be reduced. The programmable reflectarray antenna designed in the present application has the advantages of wide frequency band, low cost and simple unit structure, and has wide application potential in the fields of next-generation mobile communication, satellite communication and radar detection. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A structure schematic diagram of a wideband multi-polarization programmable reflectarray antenna provided by the embodiment of the present application;

[0012] Figure 2 A three-dimensional structure schematic diagram of an electrically controlled metasurface unit of a wideband multi-polarization programmable reflectarray antenna provided by the embodiment of the present application;

[0013] Figure 3 A plane structure schematic diagram of a patch layer of an electrically controlled metasurface unit of the embodiment of the present application;

[0014] Figure 4 This is a 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;

[0015] Figure 5a This is a schematic diagram of the structure of a low-frequency feed antenna according to an embodiment of the present invention;

[0016] Figure 5b This is a radiation performance diagram of a low-frequency feed antenna according to an embodiment of the present invention;

[0017] Figure 6a This is a schematic diagram of the structure of a high-frequency feed antenna according to an embodiment of the present invention;

[0018] Figure 6b This is a radiation performance diagram of a high-frequency feed antenna according to an embodiment of the present invention;

[0019] Figure 7 In the experiment of this embodiment of the invention, the beam direction is at the elevation angle. =0°, azimuth angle Curves showing the gain and aperture efficiency versus frequency at 0°;

[0020] Figure 8 In the experiment of this embodiment of the invention, the beam direction is... =0°, Curve of cross-polarization level versus frequency at 0°;

[0021] Figure 9 This is a diagram showing the reflection coefficients when electromagnetic waves are incident obliquely at different angles onto the electrically controlled metasurface unit in an experiment according to an embodiment of the present invention. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0023] In recent years, programmable reflector array antennas have attracted widespread attention due to their beam agility; however, research on the wideband performance of programmable reflector array antennas has not yet yielded a breakthrough. To address the narrow bandwidth issue of programmable reflector array antennas, this invention provides a wideband multi-polarization programmable reflector array antenna, comprising:

[0024] Metasurface array, feed antenna, DC control circuit board and ARDUINO microprocessor; the metasurface array includes multiple electrically controlled metasurface units;

[0025] For the structure of the metasurface array, please refer to [link / reference]. Figure 1 As shown, in this embodiment of the invention, the metasurface array contains M There are N electrically controlled metasurface units, where M and N are both natural numbers greater than 0, and M and N can be the same or different. Figure 1In the middle of 12 12 electrically controlled metasurface units are taken as an example, of course, the embodiments of the present application are not limited to this.

[0026] In order to more clearly understand the structure of the electrically controlled metasurface unit, please refer to Figure 2 The three-dimensional structure schematic diagram of the electrically controlled metasurface unit and Figure 3 The planar structure schematic diagram of the patch layer of the electrically controlled metasurface unit.

[0027] The embodiments of the present application obtain a wideband 1-bit electrically controlled metasurface unit through design. Wherein, the wideband refers to that the system can maintain stable beam scanning performance in a relatively wide continuous frequency range (such as 13GHz~20GHz); the 1-bit phase control refers to that by controlling the conduction and disconnection of the PIN diode in the electrically controlled metasurface unit, the reflection phase of the unit to the electromagnetic wave presents two discrete states (phase difference 180°), so as to realize the 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 combination with the description hereinafter.

[0028] Specifically, please refer to Figure 2 Each electrically controlled metasurface unit includes a patch layer, a first dielectric substrate layer, a ground layer, an adhesive layer, a second dielectric substrate layer and a bias line layer from top to bottom; the patch layer, the ground layer and the bias line layer are metal materials, which can be copper; the adhesive layer is used to press two dielectric substrate layers.

[0029] Wherein, the model and specific material parameters of the first dielectric substrate layer, the second dielectric substrate layer and the adhesive layer can be selected according to needs. In a preferred embodiment, the model of the first dielectric substrate layer and the second dielectric substrate layer is F4BME265, the relative dielectric constant ( ) is 2.65, and the loss tangent value ( ) is 0.0013;

[0030] The model of the adhesive layer is WL-PP300, the relative dielectric constant is 3.00, and the loss tangent value is 0.0028;

[0031] The metal structure of the patch layer in the embodiments of the present application is a double-ring cross-dipole form of inner and outer nesting. Please understand in combination with Figure 3 The patch layer is structureally symmetric about each plane coordinate axis, wherein the each plane coordinate axis includes x-axis, y-axis, u-axis and 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 an uv coordinate system; the uv coordinate system is obtained by rotating the xy coordinate system plane by 45°.

[0032] The patch layer comprises 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 arranged on the dipole arm structure corresponding to each square double-ring metal patch structure;

[0033] That is, two pin diodes are loaded in the u-axis and v-axis directions respectively; for each pin diode, the pin diode connecting the square double-ring metal patch structure and the dipole arm structure can be located at the middle position of the center point of the square double-ring metal patch structure and the intersection point of the dipole arm structure; the pin diodes in each electrically controlled metasurface unit are of the same model, for example, the four pin diodes can be MACOM brand pin diodes, and the model code can be MADP-000907-14020P.

[0034] A central metal through hole penetrating through each layer down to the bias line layer is arranged at the intersection position of the dipole arm structure, see Figure 2 It can be understood that the central metal through hole will penetrate through the first dielectric substrate layer, the ground layer, the adhesive layer and the second dielectric substrate layer, so that corresponding holes can be formed on these layers, which are all circular holes, wherein the hole diameter of the central metal through hole on the ground layer is larger than the diameter of the central metal through hole, for isolating the central metal through hole from the ground layer, and the hole diameters of the central metal through holes on the remaining layers are equal to the diameter of the central metal through hole; and a surrounding metal blind hole penetrating into the first dielectric substrate layer is arranged at the center point of each square double-ring metal patch structure, and the surrounding metal blind hole does not penetrate through the remaining layers below the first dielectric substrate layer, but contacts the ground layer.

[0035] In the embodiment of the present application, the electrically controlled metasurface unit adopts a cross-dipole form patch, and the patch structure is designed with double resonance and double polarization symmetry, which can realize 1-bit phase control and cross-polarization suppression in a wide frequency band. Those skilled in the art can understand that in the metasurface unit, double resonance design refers to optimizing the geometric structure (such as length, width, spacing, etc.) of the cross-dipole patch, so that the unit resonates at two different frequency points. The core purpose of this design is to widen the working bandwidth of the metasurface. Double polarization refers to the ability of the metasurface unit to respond or control two orthogonal polarization directions simultaneously; symmetric structure ensures consistent performance of the two polarization modes. Cross-polarization suppression refers to the technical ability to maximize the suppression of non-target polarization direction components (cross-polarization components) and only retain or enhance the target polarization direction components (co-polarization components) during electromagnetic wave transmission, reflection or control. For example, if the target is to transmit “vertical polarization” electromagnetic waves, the “horizontal polarization” component needs to be suppressed, so that the output signal contains almost only vertical polarization component.

[0036] This invention achieves excellent 1-bit phase quantization performance and cross-polarization suppression when electromagnetic waves are incident perpendicularly in u-polarization through a dual-resonance design and a dual-polarization symmetrical structure design. It locks the 180° phase difference between co-polarization and cross-polarization over a wide bandwidth by superimposing the two resonant frequencies, ensuring that the suppression effect does not decrease with frequency. The use of "cross dipole patches" makes the response characteristics of the metasurface unit to the two orthogonal polarization directions (i.e., u-polarization and v-polarization) consistent, avoiding energy leakage to the cross-polarization direction due to structural asymmetry.

[0037] See Figure 4 The bias line layer employs a fan-shaped stub structure to couple with the ground plane, generating distributed capacitance to achieve AC / DC isolation and prevent RF current from flowing into the bias line layer. In the fan-shaped stub structure, the rectangular microstrip line is the DC bias line, and the circular portion contacts the central metal via.

[0038] In this embodiment of the invention, one end of any 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 ground plane through the surrounding metal blind via. The DC bias line is connected to the positive terminal of an external DC source, and the ground plane is connected to the negative terminal of the DC source. The pin diode is turned on when the DC source outputs a high level, and turned off when the DC source outputs a low level. Furthermore, pin diodes within the same electronically controlled metasurface unit are simultaneously turned on or off.

[0039] Each electronically controlled metasurface unit, through a phase distribution encoding method, under the control of the DC control circuit board and the ARDUINO microprocessor, enables the internal pin diodes to be turned on or off, thereby achieving beam scanning of the target angle within the target frequency band.

[0040] As a preferred embodiment, the structural parameters of the electrically controlled metasurface unit are designed as follows:

[0041] Thickness of the first dielectric substrate layer The thickness is 2mm; the thickness of the floor layer The thickness is 0.035 mm; the thickness of the adhesive layer The thickness is 0.1 mm; the thickness of the second dielectric substrate layer The thickness is 0.5 mm; the electrically controlled metasurface unit is square, with a side length of... It is 7.5mm;

[0042] In the patch layer, any square double-ring metal patch structure includes a square outer ring and a square inner patch nested within the square outer ring; wherein, the outer side length of the square outer ring is... The inner side length of the square outer ring is 2.4mm. The side length of the square inner patch is 2mm. 1mm; diameter of the central metal via and the surrounding metal blind via 0.4mm; pitch of the adjacent square double-ring metal patch structure 1mm; width of the dipole arm structure 0.5mm; gap width between the pin diode pads 0.3mm; cut corner 1mm; wherein the cut corner represents the length of the corner of the square inner patch that is cut off, please refer to the relevant technical understanding in the art for details.

[0043] The diameter of the hole opened on the floor layer corresponding to the central metal via is 0.8mm;

[0044] The radius of the via pad in the bias line layer that contacts the central metal via 0.8mm, the width of the DC bias line of the bias line layer 0.3mm, the radius of the fan-shaped branch 2.5mm.

[0045] For ease of understanding, the above parameters are collectively shown in Table 1.

[0046] Table 1: Structure parameters of electronically controlled metasurface unit

[0047]

[0048] The wideband multi-polar programmable reflectarray antenna of the embodiment of the present application can have a target frequency range of 13-20GHz in use. Those skilled in the art can understand that the 13-20GHz frequency band belongs to the super high frequency (SHF) frequency band, and the frequency range of the super high frequency (SHF) is 3-30GHz. Of course, the target frequency range of the embodiment of the present application is not limited to 13-20GHz, and the wideband multi-polar programmable reflectarray antenna provided can be fine-tuned according to the corresponding target frequency range.

[0049] The embodiment of the present application can realize two-dimensional beam scanning within a range of 60° within the target frequency range. In use, the metasurface array can be placed vertically using a support or the like, the feed antenna is arranged in front of the metasurface array, directly opposite the patch layer of the metasurface array, the DC control circuit board and the ARDUINO microprocessor are arranged behind the metasurface array, wherein the DC control circuit board and the ARDUINO microprocessor are in communication connection, and the DC control circuit board and the electrically controlled metasurface unit of the metasurface array are connected.

[0050] Considering the operating frequency band of the metasurface array, the feed antenna of this invention is divided into high-frequency and low-frequency bands to verify the broadband performance of the metasurface array. That is, the feed antenna includes a low-frequency band feed antenna and a high-frequency band feed antenna.

[0051] The feed antenna in this embodiment of the invention can be any type of broadband antenna, such as a broadband horn antenna, a Vivaldi antenna feed antenna, etc. During the experiments of this invention, any type of feed antenna can be selected to design low-frequency and high-frequency feed antennas to cope with broadband scenarios. In one optional embodiment, the low-frequency and high-frequency feed antennas can be pyramidal horn antennas.

[0052] This invention relates to a pyramidal horn antenna, specifically designing a low-frequency feed antenna and a high-frequency feed antenna.

[0053] Please see Figure 5a The schematic diagram of the low-frequency feed antenna shown is as follows: Figure 5b The diagram shows the radiation performance of the low-frequency feed antenna. The waveguide section of the low-frequency feed antenna adopts the international standard waveguide size WR-75, the flange model is FDP120, and the horn angle 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 using 3D printing technology.

[0054] Please see Figure 6a The schematic diagram of the high-frequency feed antenna shown is as follows: Figure 6b The diagram shows the radiation performance of the high-frequency feed antenna. The waveguide section of the high-frequency feed antenna adopts the international standard waveguide size WR-51, the flange model is FDP180, and the horn angle 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 using 3D printing technology.

[0055] With 12 Taking 12 electrically controlled metasurface units as an example, the overall size of the prototype of the wideband multi-polarization programmable reflector array antenna in this embodiment of the invention is 215mm. 235mm The focal length is 300mm, and the distance from the feed antenna to the surface of the metasurface array is 85mm (focal diameter ratio of 0.94). Twelve 2-channel antennas are welded to the back of the metasurface array. 6 The row pin is used to connect the metasurface array and the direct current control circuit board. The bracket for fixing the metasurface array and the feed antenna is made of engineering plastic ABS material by using the fused deposition 3D printing technology, the metasurface array is made by using the PCB technology, and the lumped elements such as pin diodes and resistors are welded by using the SMT (Surface Mounted Technology) technology. In order to facilitate welding and at the same time minimize the reflection loss of the metasurface, the solder mask layer only covers the periphery of the pad.

[0056] The direct current control circuit board includes 72 8-bit shift register chips (the model can be SN74HC164DR). Considering the working voltage limit of the shift register chip, the output port of each shift register chip controls the on-off state of eight pin diodes of two electrically controlled metasurface units through the row pin and the row line. An 80Ω resistor is connected in series on the output port of each shift register chip to ensure that the current on each pin diode is near 15mA. Finally, the ARDUINO microprocessor is externally connected to realize the parallel control of all pin diodes of the metasurface array.

[0057] Specifically, the working process of the wideband multi-polarization programmable reflective array antenna for realizing beam scanning of a target angle in a target frequency band includes the following steps:

[0058] In step a1, according to the corresponding working frequency band in the target frequency band and the obtained target angle, the compensation phase of each electrically controlled metasurface unit is calculated by using a first preset formula.

[0059] Taking 13-20GHz as an example, in the experimental process of designing the antenna according to the present application, considering the working bandwidth of the wideband multi-polarization programmable reflective array antenna, in order to take into account the beam control code requirements of different frequency bands as much as possible and reduce the in-band gain attenuation, a segmented coding working form is adopted. The entire frequency band 13-20GHz is divided into three working frequency bands, and 14GHz, 17GHz and 20GHz are respectively used as the phase distribution calculation frequencies of each frequency band, so as to verify that the metasurface antenna can meet the performance within the bandwidth range.

[0060] After the design is completed, when the wideband multi-polarization programmable reflective array antenna according to the present application is actually used, the working frequency band can be a segment in the target frequency band 13-20GHz, then according to the working frequency band and the obtained target angle, the compensation phase of each electrically controlled metasurface unit is calculated by using a first preset formula, and according to the high and low of the frequency band, a low frequency band feed antenna or a high frequency band feed antenna is selected.

[0061] When the wideband multi-polarization programmable reflective array antenna realizes the beam scanning function, the compensation phase of the electrically controlled metasurface unit satisfies the first preset formula.

[0062] The first preset formula is expressed as:

[0063] ;

[0064] in, Indicates the first Compensation phase of each electrically controlled metasurface unit This is the number of the electrically controlled metasurface unit, with a value between 1 and 144; For free space wavenumber, , The wavelength is in free space and is calculated based on the center frequency of the operating frequency band. Indicates the phase center of the feed antenna to the first... The spatial distance between each electrically controlled metasurface unit, with the center of the metasurface array as the origin, is... The position vector of each electrically controlled metasurface unit is It can be detected; the unit vector for the specified beam direction is , This represents the azimuth angle, and its value can be any value within the range of 0° to 360°. This represents the elevation angle, and its value is the target angle. For the introduction of a reference phase;

[0065] For example, for the first defined operating frequency band, the phase distribution calculation frequency is 14GHz. If the target angle at this time... It's 30°, for each electrically controlled metasurface unit. and Given that, the value can be calculated using 14GHz. , represented as , For wave speed, This allows us to calculate the compensation phase of the electrically controlled metasurface unit. Similarly, the compensation phase of each electrically controlled metasurface unit can be calculated.

[0066] Step a2: For each electrically controlled metasurface unit, determine the working state of the electrically controlled metasurface unit using the second preset formula; wherein the working state includes state0 or state1.

[0067] The second preset formula is expressed as:

[0068] .

[0069] For each electrically controlled metasurface unit, its compensation phase is judged using the second preset formula, which can determine whether the working state of the electrically controlled metasurface unit is state0 or state1, thereby quantifying the spatial phase into the working state.

[0070] Step a3, according to the working state of each electrically controlled metasurface unit, the phase distribution of all electrically controlled metasurface units is encoded by 01 encoding mode, and the encoding result is output to the ARDUINO microprocessor, wherein state0 state is encoded as 0, and state1 state is encoded as 1.

[0071] Steps a1 to a3 can be completed by a software program, for example, a MATLAB program can be loaded by a computer.

[0072] Therefore, the working state of each electrically controlled metasurface unit is encoded as 0 or 1, and the working state of all electrically controlled metasurface units can be represented by a 01 encoding sequence according to a certain order. The 01 encoding sequence is sent to the ARDUINO microprocessor as an encoding result.

[0073] Step a4, according to the encoding result, the ARDUINO microprocessor controls the 8-bit shift register chip in the direct current control circuit board to output high level or low level to the connected electrically controlled metasurface unit, so as to control the pin diode in the electrically controlled metasurface unit to be turned on or turned off; wherein the output port of each 8-bit shift register chip controls the on-off state of all pin diodes in two electrically controlled metasurface units through the pin and the cable.

[0074] The pin diode is turned on when the state is state1, and the pin diode is turned off when the state is state0.

[0075] The experimental process proves that the working form of the embodiment of the application uses segmented encoding, and according to the selected frequency By calculating the phase distribution of each working frequency band by the first preset formula and the second preset formula, the phase distribution information obtained is in the form of 01 encoding, which is used to adjust the state of each electrically controlled metasurface unit on the metasurface array through the direct current control board, so that the metasurface array presents the desired phase distribution. The wideband multi-polarization programmable reflective array antenna radiates the corresponding beam pattern, and the beam scanning within 13-20GHz can be realized.

[0076] In the wide-band multi-polarization programmable reflective array antenna provided by the embodiment of the present application, the metasurface array comprises a plurality of electrically controlled metasurface units, the electrically controlled metasurface unit adopts a cross-dipole form patch, and the patch structure is designed in a dual-resonance mode and a dual-polarization symmetric structure mode, so that 1-bit phase control and cross-polarization suppression in a wide frequency band can be realized. The cross-direct-current isolation structure of the bias line layer adopts a distributed capacitor generated by coupling of a fan-shaped branch and a ground plate layer instead of a radio frequency capacitor, so that the cross-direct-current isolation of the electrically controlled metasurface unit in a wide frequency band is realized, and meanwhile, the complexity and cost of the unit structure can be reduced. The programmable reflective array antenna designed in the present application has the advantages of wide frequency band, low cost and simple unit structure, and has wide application potential in the fields of next-generation mobile communication, satellite communication and radar detection.

[0077] In order to facilitate understanding of the effect of the wide-band multi-polarization programmable reflective array antenna provided by the present application, the following gives relevant comparison and experimental demonstration.

[0078] 1. Comparison with a Ka-band wide-band reconfigurable reflective unit and array antenna (CN 114256629 A);

[0079] The patent designs a wide-band reconfigurable reflective unit and array antenna, and the relative bandwidth is 25%; in the range of 31GHz-40GHz, the beam scanning in a two-dimensional space can be realized within ±50°.

[0080] Based on the dual-resonance structure and multi-polarization control principle, the present application adopts a wide-band electrically controlled metasurface unit, realizes a multi-polarization (linear polarization / circular polarization) wide-band programmable reflective array antenna through dual-resonance patch coupling design, and can realize two-dimensional beam scanning within a range of 60° in a frequency band of 13-20GHz. Specifically, the 3-dB gain bandwidth is improved to 55.6% (13-23GHz) through the dual-resonance structure, covering a continuous ultra-wide frequency band; the simulation cross-polarization level is <-32dB, and the test is <-19.47dB (the patent does not provide specific numerical values), which significantly suppresses cross-polarization interference; through analysis of the reflection coefficient under different incident angles, the stability of the reflection characteristic within a range of 30° oblique incidence is verified.

[0081] 2. Comparison with a circularly polarized decoupling reconfigurable reflective array antenna based on a metasurface (CN 120073334 A);

[0082] The patent designs a circular polarization decoupling reconfigurable reflectarray antenna based on a metasurface, which realizes 1-bit phase reconfiguration in the range of 6.9-7.5 GHz (relative bandwidth of about 8.1%). However, this design only supports circular polarization (left-handed / right-handed) operation and cannot cover linear polarization scenarios; the working frequency band is relatively narrow (relative bandwidth is only 8.1%), which is difficult to meet the wideband communication demand; the cross-polarization level is <-15 dB, which only meets the low axial ratio requirement and has limited interference suppression capability.

[0083] Based on the dual-resonance structure and multi-polarization control principle, the present application adopts a wideband electrically controlled metasurface unit to realize a wideband programmable reflectarray antenna with linear polarization / circular polarization multi-polarization operation through dual-resonance patch coupling design. Specifically, the dual-resonance structure improves the 3-dB gain bandwidth to 55.6% (13-23 GHz, relative bandwidth is 6.8 times that of the patent), covering a continuous ultra-wide frequency band; the simulation cross-polarization level is <-32 dB (test <-19.47 dB), which is significantly better than the <-15 dB of the patent; by analyzing the reflection coefficient under different incident angles, the stability of the reflection characteristics within the range of 30° oblique incidence is verified.

[0084] Through multi-polarization control and wideband dual-resonance structure, the present application solves the problems of polarization type coverage (only circular polarization), bandwidth coverage (insufficient relative bandwidth), cross-polarization suppression (low level), and oblique incidence stability (not verified) of the patent, and provides a solution that meets the needs of multiple scenarios for wideband high-speed beam control.

[0085] 3. Comparison with a wideband reconfigurable reflective metasurface antenna (CN 115051150 A);

[0086] The patent designs a wideband reconfigurable reflective metasurface antenna with a 3-dB operating bandwidth of 9.4-11 GHz, which can realize a beam scanning range of ±50°, but this design only supports linear polarization operation and cannot cover circular polarization scenarios, and the unit structure is complex;

[0087] Based on the principle of wideband multi-polarization programmable reflectarray, the present application adopts a simpler electrically controlled metasurface unit structure to realize multi-polarization operation with linear polarization and circular polarization switching, 13-23 GHz ultra-wide frequency band (3-dB gain bandwidth), and solves the problems of single polarization dimension, insufficient bandwidth, and complex structure of the patent.

[0088] The comparison of the present application with other similar technologies is shown in Table 2. First, compared with existing single linear polarization or single circular polarization wideband operation, the present application realizes a wideband programmable reflectarray antenna with multi-polarization operation. Second, the dual-resonance structure used in the present application realizes a 3-dB gain bandwidth of 55.6%, which is higher than the relative bandwidth of the current existing antennas of the same type.

[0089] Table 2 Comparison of the present application and other similar technologies

[0090]

[0091] Reference technology 1 is Luyen H, Zhang Z, Booske J H, et al. Wideband, Beam-Steerable Reflectarrays Based on Minimum-Switch Topology, Polarization-Rotating Unit Cells[J]. IEEE Access, 2019, 7: 36568-36578;

[0092] Reference technology 2 is Wu F, Lu R, Wang J, et al. Circularly Polarized One-Bit Reconfigurable ME-Dipole Reflectarray at X-Band[J]. IEEE Antennas and Wireless Propagation Letters, 2022, 21(3): 496-500;

[0093] Reference technology 3 is Zhou S G, 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;

[0094] Reference technology 4 is Xiang B J, 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.

[0095] See Figure 7 and Figure 8 , Figure 7 The beam pointing is an elevation angle = 0°, azimuth angle Gain and aperture efficiency versus frequency plots at = 0°, Figure 8 is directed to = 0°, Cross-polarization level versus frequency plots at = 0°.

[0096] Figure 7 and Figure 8 The simulation results show that the maximum aperture efficiency is 23.9%, the 3-dB gain bandwidth is 55.6%, the operating frequency band is 13-23 GHz, and the cross-polarization level in the entire frequency band is less than -32 dB; the test results show that the maximum aperture efficiency is 17.7%, the 3-dB gain bandwidth is 55.6%, the operating frequency band is 13-23 GHz, and the cross-polarization level in the entire frequency band is less than -19.47 dB. The designed wideband multi-polarization programmable reflective array antenna provides a new design scheme for realizing high-speed beam steering in a wide frequency band, and has the advantages of wide frequency band, flexible beam switching and low cost.

[0097] Since the electromagnetic waves radiated by the feed source are incident on the electrically controlled metasurface from different angles, the variation of the reflection coefficients of "state1" and "state0" in the operating frequency band with the incident angle is analyzed. The reflection coefficients of electromagnetic waves obliquely incident on the wideband 1-bit electrically controlled metasurface unit at different angles are shown in Figure 9 The results show that the reflection characteristics of the wideband electrically controlled metasurface remain stable within a 30° oblique incident angle range.

[0098] It should be noted that in the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0099] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0100] In the description of the specification, reference to "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "in some embodiments", "an example", "a specific example", or "some examples" in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Also, the terminology used in the description is for the purpose of describing particular embodiments only and is not intended to be limiting. It is also possible in the present application that

[0101] The preferred embodiments of the application described above are intended to be merely exemplary and those skilled in the art will readily suggest modifications, equivalent replacements, improvements and the like without departing from the spirit and principles of the application. Any modification, equivalent replacement, improvement and the like made within the spirit and principles of the application are intended to be included in the scope of the application.

Claims

1. A wideband multi-polarization programmable reflective array antenna, characterized in that, It includes a metasurface array, a feed antenna, a DC control circuit board, and an ARDUINO microprocessor; the metasurface array includes multiple electrically controlled metasurface units; each electrically controlled metasurface unit includes, from top to bottom, a patch layer, a first dielectric substrate layer, a ground plane layer, an adhesive layer, a second dielectric substrate layer, and a bias line layer; the patch layer, the ground plane layer, and the bias line layer are made of metal. The patch layer is structurally symmetrical about each planar coordinate axis, including four square double-ring metal patch structures and dipole arm structures connecting the center points of two square double-ring metal patch structures diagonally. A pin diode is disposed on each dipole arm structure corresponding to each square double-ring metal patch structure. A central metal via is disposed at the intersection of the dipole arm structures, penetrating downwards through each layer to connect to the bias line layer. The opening diameter of the central metal via on the ground plane is larger than the diameter of the central metal via, while the opening diameter of the central metal via on the other layers is equal to the diameter of the central metal via. A surrounding metal blind via is disposed at the center point of each square double-ring metal patch structure, penetrating downwards 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 and achieve AC / DC isolation. Each electronically controlled metasurface unit, through a phase distribution encoding method, under the control of the DC control circuit board and the ARDUINO microprocessor, enables the internal pin diodes to be turned on or off, thereby achieving beam scanning of the target angle within the target frequency band.

2. The wideband multi-polarization programmable reflector array antenna according to claim 1, characterized in that, One end of any 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 ground plane through the surrounding metal blind via; the DC bias line is connected to the positive terminal of an external DC source, and the ground plane is connected to the negative terminal of the DC source.

3. The wideband multi-polarization programmable reflector array antenna according to claim 1, characterized in that, The planar coordinate axes include the x-axis, y-axis, u-axis, and v-axis; wherein the x-axis and y-axis are perpendicular to each other, forming the xy coordinate system; the u-axis and v-axis are perpendicular to each other, forming the uv coordinate system; the uv coordinate system is obtained by rotating the xy coordinate system plane by 45°.

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

5. The wideband multi-polarization programmable reflector array antenna according to claim 1, characterized in that, The first dielectric substrate layer and the second dielectric substrate layer are of type F4BME265, with a relative permittivity of 2.65 and a loss tangent of 0.0013. The adhesive layer is of type WL-PP300, with a relative permittivity of 3.00 and a loss tangent of 0.0028. The pin diodes in each electrically controlled metasurface unit are of the same type.

6. The wideband multi-polarization programmable reflector array antenna according to claim 1, characterized in that, The feed antenna includes a low-frequency feed antenna and a high-frequency feed antenna.

7. The wideband multi-polarization programmable reflector array antenna according to claim 6, characterized in that, Both the low-frequency and high-frequency feed antennas are pyramidal horn antennas; specifically, the waveguide section of the low-frequency feed antenna adopts the international standard waveguide size WR-75, the flange model is FDP120, and the horn angle 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 horn angle is 28.95mm. 22.48mm 16mm; The physical waveguide portions of the low-frequency and high-frequency feed antennas adopt a waveguide coaxial conversion structure, while the horn flare portion is fabricated using aluminum alloy 3D printing technology.

8. The wideband multi-polarization programmable reflector array antenna according to claim 1, characterized in that, The process by which the wideband multi-polarization programmable reflector antenna performs beam scanning of the target angle within the target frequency band includes: Based on the corresponding operating frequency band in the target frequency band and the obtained target angle, the compensation phase of each electronically controlled metasurface unit is calculated using the first preset formula. For each electrically controlled metasurface unit, the operating state of the electrically controlled metasurface unit is determined using a second preset formula; wherein the operating state includes state0 or state1. Based on the working state of each electronically controlled metasurface unit, phase distribution encoding is performed on all electronically controlled metasurface units using a 01 encoding method, and the encoding result is output to the ARDUINO microprocessor, wherein state0 is encoded as 0 and state1 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 low level to the connected electronically controlled metasurface unit to control the conduction or disconnection of the pin diodes inside the electronically controlled metasurface unit; wherein, the output port of each 8-bit shift register chip controls the on / off state of all pin diodes in two electronically controlled metasurface units through pin headers and ribbon cables.

9. The wideband multi-polarization programmable reflector array antenna according to claim 8, characterized in that, The first preset formula is expressed as: ； in, Indicates the first Compensation phase of each electrically controlled metasurface unit; For free space wavenumber, , The wavelength is in free space and is calculated based on the center frequency of the operating frequency band. Indicates the phase center of the feed antenna to the first... The spatial distance between each electrically controlled metasurface unit, with the center of the metasurface array as the origin, is... The position vector of each electrically controlled metasurface unit is The unit vector specifying the beam direction is , This represents the azimuth angle, and its value can be any value within the range of 0° to 360°. This represents the elevation angle, and its value is the target angle. For the introduction of a reference phase; The second preset formula is expressed as: 。 10. The broadband multi-polarization programmable reflector array antenna according to any one of claims 1, 8, and 9, characterized in that, The target frequency band ranges from 13 to 20 GHz.

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