Dielectric layer design method for enhancing performance of phased-array antenna

Abstract

The invention belongs to the field of antenna design, and discloses a dielectric layer design method for enhancing the performance of a phased-array antenna. The method mainly comprises the following two steps: step 1, establishing a dielectric layer material property and metal layer size parameter optimization model suitable for the laminated antenna according to the broadband wide-angle scanning characteristic requirement of the phased-array antenna; optimal design parameters are obtained by solving the optimization model; and step 2, according to the optimal parameter result in the step 1, designing a unit cell or a structure of a dielectric layer based on a scattering parameter inversion method so as to design the dielectric layer with the optimal dielectric property and further realize the expected broadband wide-angle scanning property. The broadband wide-angle scanning characteristic of the phased array unit is realized by designing the dielectric layer unit, and the unit not only has good matching characteristic and polarization purity, but also realizes lightweight design.

Description

Technical Field

[0001] The invention belongs to the field of antenna design, and in particular relates to a dielectric layer design method for enhancing the performance of a phased array antenna. Background Art

[0002] Phased array antennas are core components of modern communications and military radar systems. Their fast transmission and reception and beam pointing switching capabilities play a vital role in improving system performance, enhancing signal coverage, and improving target detection accuracy. However, with the continuous development of communication and radar technology, the performance requirements for phased array antennas are also increasing, especially the ability to achieve wide-wavelength scanning in a wide frequency band. Therefore, it is necessary to improve the impedance matching characteristics of the antenna to achieve wide-band and wide-angle scanning in the band.

[0003] Stacking dielectric layers is a common method for realizing broadband and wide-angle scanning of phased array antennas. For example, CN118645801A proposes a phased array antenna unit with four substrate layers. The antenna works in the Ka band and adopts microstrip antenna broadband technologies such as L-type probe feeding, H-shaped slot coupling feeding, and multi-layer coupling feeding to realize low-profile and broadband design of the antenna unit. The relative bandwidth reaches 14.85% (26.18-30.34 GHz). The use of SIW resonant cavity structure, defective structure floor and "L-shaped" parasitic patch structure of the decoupling surface reduces the mutual coupling between antenna elements, so that the antenna has two-dimensional wide-angle scanning (>±47°), high isolation (>19 dB), low profile (2.21 mm, about 0.2λ0), easy processing and other characteristics; CN117977168A proposes a multi-layer phased array antenna design method, which realizes the working characteristics of wide-bandwidth and wide-angle scanning by using a metal grid as a resonant cavity structure for the antenna, and provides a fixing screw installation point. This design scheme realizes the collaborative design of antenna unit radiation performance optimization and screw layout optimization without affecting the antenna working characteristics, solves the problem that the phased array antenna array design based on the existing design process requires multiple iterations and high calculation amount, and shortens the design cycle.

[0004] However, in the design of stacked antennas, the selection of dielectric layers is also crucial to improving antenna performance. At present, there is a mismatch between the properties of traditional PCB materials (dielectric properties and thickness, etc.) and the material properties required to achieve antenna performance, which also limits the performance improvement space and design flexibility of the antenna. In addition, 3D printing technology can achieve complex internal structure and material distribution design, which also provides unprecedented possibilities for designing dielectric layers with specific dielectric properties. Therefore, it is necessary to propose a dielectric layer design method that takes into account the feasibility of 3D printing technology and is suitable for improving the performance of phased array antennas, which can provide technical support for improving the performance of antennas. Summary of the invention

[0005] The present invention provides a dielectric layer design method for enhancing the performance of a phased array antenna, which can effectively improve the impedance matching characteristics of the phased array antenna by designing the dielectric layer microstructure of the phased array antenna, thereby realizing a wide-band and wide-angle scanning design.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A dielectric layer design method for enhancing the performance of phased array antennas mainly includes two steps: Step 1 is to establish an optimization model of dielectric layer material properties and metal layer size parameters suitable for stacked antennas based on the wide bandwidth and angular scanning characteristics of phased array antennas; the optimal design parameters are obtained by solving the optimization model; Step 2 is to design a unit cell or structure of the dielectric layer based on the scattering parameter inversion method according to the optimal parameter result of Step 1, so as to design a dielectric layer with optimal dielectric properties, thereby achieving the expected wide bandwidth and angular scanning characteristics.

[0008] In the step 1, the optimization model is designed to achieve the wide bandwidth angular scanning characteristics of the stacked antenna as the design goal, the dielectric properties and thickness of the dielectric layer constituting the stacked antenna and the size parameters of the radiation patch are used as optimization variables, and the optimal result is solved by the optimization algorithm, wherein the wide bandwidth angular scanning characteristics are evaluated by a standing wave ratio less than a specified value.

[0009] In step 2, the implementation of the method for designing a unit cell or structure of a dielectric layer based on the scattering parameter inversion method requires first analyzing the characteristics of the designed dielectric layer and the design factors that need to be considered, and then determining the design scheme of the material, and then determining the initial volume ratio of the dielectric layer required to have the optimal material properties based on the empirical formula, and then determining the initial configuration of the unit cell and performing parameterized modeling, and then evaluating the dielectric constant of the dielectric layer based on the scattering parameter inversion method, and obtaining the optimal dielectric layer unit cell or configuration by establishing an optimization model, and finally solving the dielectric layer microstructure with the optimal dielectric properties through an intelligent optimization algorithm. Among them, the 3D printing accuracy and the feasibility of the metal layer process are mainly considered in the design process of the dielectric layer unit cell to ensure that the designed dielectric layer has manufacturability.

[0010] The present invention utilizes a dielectric layer design method for enhancing the performance of a phased array antenna, and realizes the wide bandwidth and angle scanning characteristics of a phased array unit by designing a dielectric layer unit. The unit not only has good matching characteristics and polarization purity, but also realizes a lightweight design. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a design flow chart of the present invention;

[0012] Figure 2 Schematic diagram of a dual Floquet port network of the present invention: (a) exploded view, (b) overall view;

[0013] Figure 3 The typical structure diagram of the phased array antenna with matching layer of the present invention: (a) unit cell structure; (b) dielectric properties;

[0014] Figure 4 The unit cell configuration and dielectric properties of the matching layer of the present invention are as follows: (a) unit cell structure; (b) dielectric properties;

[0015] Figure 5 The unit cell configuration and dielectric properties of the dielectric layer 1 of the present invention;

[0016] Figure 6 Designing a configuration for the dielectric layer 2 of the present invention;

[0017] Figure 7 The overall solution after optimization of the designed antenna of the present invention;

[0018] Figure 8 The scanning standing wave ratios of the optimized overall solution of the designed antenna of the present invention and the reference antenna are as follows: (a) normal standing wave ratio, (b) E-plane scanning standing wave ratio, and (c) H-plane scanning standing wave ratio;

[0019] Fig. 9 The directional diagrams of the antenna designed for the present invention are: (a) E-plane directional diagram, (b) H-plane directional diagram; DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0021] Embodiment 1: A dielectric layer design method for enhancing the performance of phased array antenna

[0022] The design process of the design method is as follows Figure 1 As shown, the implementation steps can be summarized into two steps: Step 1 is the optimization design of the dielectric layer material properties and metal layer parameters; Step 2 is the design of the dielectric layer unit cell / structure based on the scattering parameter inversion method.

[0023] The step 1: according to the wide bandwidth and angle scanning characteristic requirements of the phased array antenna, an optimization model of the dielectric layer material properties and the metal layer size parameters is established, and the optimal dielectric constant and metal layer size parameters are obtained by solving the optimization model.

[0024] Step 2: Based on the optimal result in step 1, the unit cell or structure of the dielectric layer is designed based on the scattering parameter inversion method. The design process needs to comprehensively consider the 3D printing accuracy and the feasibility of the metal layer process. Specifically, the design scheme of each dielectric layer is first determined by analyzing the hierarchical relationship and design points of each dielectric layer, and then the initial volume ratio of the material is determined according to the optimal dielectric constant based on the empirical formula (1): Among them, εreff is the optimal dielectric constant, ε i is the dielectric constant of the i-th type of material, V i is the volume of the i-th type of material; the initial size parameters of the designed dielectric layer microstructure are determined according to the above volume ratio; then, the dielectric properties of the designed dielectric layer material are evaluated based on the scattering parameter inversion method; the scattering parameter inversion method is based on the equivalent medium theory, which equates the actual artificial medium to a uniform medium, and analyzes the scattering parameters (S 11 and S 21 ) to determine key parameters such as equivalent relative permittivity, equivalent relative magnetic permeability, refractive index and wave impedance. The advantage of this method is that it can accurately evaluate the dielectric properties of artificial dielectric materials, providing a reliable theoretical basis for designing dielectric layer cells or structures with specific dielectric properties; when designing microstructures, the dielectric layer is guaranteed to have stable dielectric properties and structural strength by parameter modeling the initial unit cell configuration and performing array design.

[0025] Figure 2 This is a schematic diagram of a two-port network for the scattering parameter inversion method, which mainly involves four parameters: the equivalent relative dielectric constant (ε eff ), equivalent relative permeability (μ eff ), refractive index (n) and wave impedance (z). The above four parameters can be obtained by scattering parameters (S 11 and S 21 ) is calculated based on formula (2):

[0026]

[0027] Finally, taking the optimal dielectric constant value as the optimization target, the microstructure size as the design variable, and the 3D printing accuracy as the constraint condition, an optimal dielectric layer microstructure optimization model is established. The dielectric layer material microstructure with a specific dielectric constant can be obtained by solving it through an intelligent optimization algorithm.

[0028] Example 2: The typical structure of the X-band stacked phased array antenna is designed to optimize its scanning characteristics

[0029] Figure 3 It is a typical structure of the X-band stacked phased array antenna, the overall size of the unit is 12mm×12mm, and it consists of a feeding area, a radiation area, and a matching area;

[0030] The feeding area is composed of a 50Ω coaxial line, a signal hole, a lower metal ground, a one-to-two stripline, an upper metal ground with an "I"-shaped gap, two layers of Rogers RT / duroid 6002 dielectric plates and a middle bonding sheet; wherein the 50Ω coaxial line serves as a signal input channel, the signal hole transmits current to the stripline, the stripline realizes impedance conversion by one-to-two (realizing impedance conversion from 50Ω to 100Ω), the lower metal ground and the metal shielding tape play the role of shielding and grounding, and the upper metal ground with an "I"-shaped gap is used to couple the signal upward to the radiation area.

[0031] The radiation zone is composed of a lower metal radiation layer 1 with a cut angle, an upper metal radiation layer 2 with a cut angle, a dielectric layer 2 between the metal radiation layers 1 and 2, and a dielectric layer 1 between the upper metal ground and the lower metal radiation layer 1; wherein the metal radiation layer 1 and the metal radiation layer 2 interact with each other through the dielectric layer in the middle to generate a dual-frequency resonance mode to achieve signal radiation;

[0032] The matching area is composed of a matching dielectric layer and a foam layer, wherein the matching dielectric layer is used to adjust the matching characteristics of the antenna, and the foam layer is used to adjust the distance between the matching layer and the metal radiation layer.

[0033] The wide bandwidth and angular scanning design of the X-band stacked phased array antenna is used to achieve the impedance matching performance of the phased array antenna at different scanning angles, with the difference between the normal standing wave ratio and the target value 2 (f FX =VSWR-2), the difference between the E-surface scanned to 60° and the target value of 2.5 (f E =VSWR-2.5), the difference between the VSWR value (f) and the target value (2.5) when the H plane is scanned to 60° H =VSWR-2.5) is minimized as the objective function. At the same time, parameters that have a significant impact on the radiation mechanism and impedance matching characteristics of the antenna are selected, including the dielectric constant (ε r1 ) and thickness (h1), foam layer thickness (h foam ), the dielectric constant of the radiation zone dielectric layer 1 (ε r2 ) and thickness (h2), dielectric constant of dielectric layer 2 (ε r3 ) and thickness (h3), the size of metal radiation layer 1 (x1, y1), the size of metal radiation layer 2 (x2, y2), etc. are used as design variables, and the section height H (<10mm) is used as a constraint to establish the following optimization model:

[0034]

[0035] The antenna is processed by powder 3D printing technology, and the material is nylon PA12. The waveguide method is used to test the solid sample to obtain the specific values ​​of dielectric constant 2.45 and dielectric loss 0.017. Considering that the minimum size that can be achieved by 3D printing is 0.5mm, the lower bound lb of the above optimization model can be determined as [1,1,1,1,1,1,1,7,8,4,7], and the upper bound ub =[2.45,3,3,2.45,3,2.45,3,9,10,6,9], and take its initial value as X initial =[2.45,2,2,2.45,2,2.45,2,8,5,8], and use high-frequency simulation software HFSS to simulate the performance. Matlab-HFSS-API combined with genetic algorithm is used to solve the optimization model, and the optimal solution is X=[1.9,1.77,2.21,1.49,2.53,1.57,2.20,7.85,9.23,4.71,7.90]. At this time, the normal VSWR is less than 2, the E-plane scan to 60° VSWR is less than 2.5, and the H-plane scan to 60° VSWR is less than 2.5.

[0036] The dielectric layer design is based on the optimal solution of the above optimization, and the following optimization model is established to design a dielectric layer with specific dielectric properties:

[0037]

[0038] Among them, χ is the optimization variable, lb is its lower bound, and ub is its upper bound; f εr is the equivalent dielectric constant of the dielectric layer composed of a unit cell, f goal is the optimal value of the dielectric layer parameters.

[0039] Figure 4 The unit cell configuration and dielectric properties of the antenna matching layer in this embodiment are as follows. Taking nylon PA12 powder for 3D printing as an example, to achieve the design requirement of a dielectric constant of 1.9, Figure 4 The "cross" unit cell in (a) is parameterized and modeled, and then a 4×4 unit cell is arranged to form a complete dielectric layer to ensure that the dielectric layer has stable dielectric properties and structural strength. The final dielectric layer is composed of nylon and air (dielectric constant 1). The initial volume ratio V can be obtained from formula (4). Nylon :V air =0.62:0.38, the initial value of dimension a is 1.15 mm, and the value range is [0.5, 2]. This value range can ensure that the designed dielectric layer can be realized by 3D printing technology. By solving the optimization model (4), it can be obtained that when the key parameter a = 1.3, the dielectric constant is 1.9 and the loss tangent is 0.02, such as Figure 4 (b) as shown.

[0040] Figure 5 The unit cell configuration and dielectric properties of the antenna dielectric layer 1 in this embodiment; similarly, the dielectric layer 1 adopts Figure 5 (a) The "cross" shaped unit cells are arranged in a 4×4 array to form the required dielectric layer. The design variable is b. From formula (1), the initial volume ratio can be obtained as V Nylon :V air =0.43:0.57, the initial value of b is 0.73mm, and the value range is still [0.5,2] to ensure the process feasibility of the designed material. Further, by solving the optimization model (4), it can be obtained that when b = 1.1mm, the dielectric constant is 1.57 and the loss tangent is 0.02. The solution is as follows Figure 5 (b) as shown.

[0041] Figure 6 For the configuration design of the antenna dielectric layer 2 in this embodiment, since the dielectric layer 2 needs to be processed with metal radiation layers on the upper and lower sides, it is necessary to consider whether there is enough material plane to arrange the metal radiation layer when designing the unit cell. Continuing to use the unit cell design cannot meet the 3D printing accuracy. Therefore, it is proposed as follows Figure 6 The dielectric layer configuration shown in the figure has optimized variables including d, e, f, and g. It is combined with the above-mentioned "cross" matching layer and dielectric layer 1 to form an antenna unit configuration. Through optimization, it can be found that when d = 2.2mm, e = 4.6mm, f = 1.53mm, and g = 10.2mm, the radiation performance of the antenna can meet the normal VSWR < 2, the E-plane scan to 60° VSWR < 2.5, and the H-plane scan to 60° VSWR < 2.5.

[0042] Figure 7 It is an overall solution after the antenna is optimized in this embodiment, and is composed of a dielectric layer designed based on the above design process.

[0043] Figure 8 is a comparative analysis result of the standing wave ratio of the antenna in this embodiment and the reference antenna, wherein the reference antenna is an antenna with a nylon material as a dielectric substrate without microstructure design; compared with the reference antenna, the optimized antenna dielectric layer is 47.89% lighter; and the designed antenna can meet the X-band (8-12GHz) VSWR wide bandwidth angle scanning characteristics, which is significantly better than the reference antenna;

[0044] Figure 8 (a) is the normal standing wave ratio of the optimized overall antenna scheme described in this embodiment and the reference antenna at different frequencies. It can be found that the reference antenna only meets the VSWR less than 2 at 2-9.75GHz, and the VSWR reaches 15 at 10.5GHz, while the designed antenna can meet the X-band (8-12GHz) VSWR less than 2.

[0045] Figure 8 (b) is the E-plane scanning standing wave ratio of the optimized overall antenna scheme described in this embodiment and the reference antenna at different frequencies. It can be found that the standing wave ratio of the reference antenna at scanning angles of 30°, 45°, and 60° is greater than 2.5, and as the scanning angle increases, the standing wave ratio improves slightly. The designed antenna can achieve a standing wave ratio of less than 2.5 when the scanning angles are 30°, 45°, and 60°.

[0046] Figure 8 (c) is the H-plane scanning standing wave ratio of the overall optimized antenna in this embodiment and the reference antenna at different frequencies. It can be found that the standing wave ratio of the reference antenna at scanning angles of 30°, 45°, and 60° is greater than 2.5, and as the scanning angle increases, the standing wave ratio deteriorates more significantly. The designed antenna can achieve a standing wave ratio of less than 2.5 at scanning angles of 30°, 45°, and 60°.

[0047] Fig. 9 The E-plane and H-plane radiation patterns of the antenna after optimization in this embodiment show that for all sampling frequencies, the gain drop of the designed antenna is less than 2dB within the range of ±45°, and the gain drop is less than 4dB within the range of ±60°. From the perspective of the cross-polarization range, whether it is the E-plane or the H-plane, the cross-polarization of the designed antenna is below -35dB within the range of ±90°, which has good polarization purity.

[0048] In summary, this embodiment first finds the optimal material properties and size parameters through dielectric layer parameter optimization, and then designs the dielectric layer unit cell or structure based on the scattering parameter inversion method, and comprehensively considers the 3D printing accuracy and the feasibility of the metal layer process, and finally obtains the specific dielectric layer size and dielectric parameters. The manufacturability of the dielectric layer is achieved and the designed antenna can achieve good matching characteristics and good polarization purity, thereby verifying the effectiveness of the proposed method.

Claims

1. A dielectric layer design method for enhancing the performance of a phased array antenna, characterized in that: There are two steps: Step 1 is to establish an optimization model for the material properties of the dielectric layer and the size parameters of the metal layer suitable for the stacked antenna in response to the wide bandwidth and angular scanning characteristics of the phased array antenna; and obtain the optimal design parameters by solving the optimization model; Step 2 is to design a unit cell or structure of the dielectric layer based on the scattering parameter inversion method according to the optimal parameter result of step 1, so as to design a dielectric layer with optimal dielectric properties, thereby achieving the expected wide bandwidth angle scanning characteristics.

2. The dielectric layer design method for enhancing the performance of a phased array antenna according to claim 1, characterized in that: In the step 1, the optimization model is designed to achieve the wide bandwidth angular scanning characteristics of the stacked antenna as the design goal, the dielectric properties and thickness of the dielectric layer constituting the stacked antenna and the size parameters of the radiation patch are used as optimization variables, and the optimal result is solved by the optimization algorithm, wherein the wide bandwidth angular scanning characteristics are evaluated by a standing wave ratio less than a specified value.

3. The dielectric layer design method for enhancing the performance of a phased array antenna according to claim 1, characterized in that: In step 2, the implementation of the method for designing a unit cell or structure of a dielectric layer based on the scattering parameter inversion method requires first analyzing the characteristics of the designed dielectric layer and the design factors that need to be considered, and then determining the material design scheme, and then determining the initial volume ratio of the dielectric layer required to have optimal material properties based on an empirical formula, and then determining the initial configuration of the unit cell and performing parametric modeling, and then evaluating the dielectric constant of the dielectric layer based on the scattering parameter inversion method, and obtaining the optimal dielectric layer unit cell or configuration by establishing an optimization model, and finally solving the dielectric layer microstructure with optimal dielectric properties through an intelligent optimization algorithm; wherein, in the design process of the dielectric layer unit cell, 3D printing accuracy and the feasibility of the metal layer process are focused on to ensure that the designed dielectric layer has manufacturability.

4. The dielectric layer design method for enhancing the performance of a phased array antenna according to claim 1, characterized in that: There are two steps: The step 1: according to the wide bandwidth and angle scanning characteristic requirements of the phased array antenna, an optimization model of the dielectric layer material properties and the metal layer size parameters is established, and the optimal dielectric constant and metal layer size parameters are obtained by solving the optimization model; Step 2: Based on the optimal result in step 1, the unit cell or structure of the dielectric layer is designed based on the scattering parameter inversion method. The design process needs to comprehensively consider the 3D printing accuracy and the feasibility of the metal layer process. Specifically, the design scheme of each dielectric layer is first determined by analyzing the hierarchical relationship and design points of each dielectric layer, and then the initial volume ratio of the material is determined according to the optimal dielectric constant based on the empirical formula (1): Among them, ε reff is the optimal dielectric constant, ε i is the dielectric constant of the i-th type of material, V i is the volume of the i-th type of material; the initial size parameters of the designed dielectric layer microstructure are determined according to the above volume ratio; then, the dielectric properties of the designed dielectric layer material are evaluated based on the scattering parameter inversion method; The scattering parameter inversion method is based on the equivalent medium theory, which treats the actual artificial medium as a homogeneous medium. 11 and S 21 ) to determine key parameters such as equivalent relative permittivity, equivalent relative permeability, refractive index and wave impedance; The scattering parameter inversion method mainly involves four parameters: equivalent relative dielectric constant (ε eff ), equivalent relative magnetic permeability (μ eff ), refractive index (n) and wave impedance (z); the above four parameters are expressed by the scattering parameter (S 11 and S 21 ) is calculated based on formula (2): Finally, taking the optimal dielectric constant value as the optimization target, the microstructure size as the design variable, and the 3D printing accuracy as the constraint condition, an optimal dielectric layer microstructure optimization model is established. The dielectric layer material microstructure with a specific dielectric constant can be obtained by solving it through an intelligent optimization algorithm.

5. The dielectric layer design method for enhancing the performance of a phased array antenna according to claim 4, characterized in that: The typical structure of the X-band stacked phased array antenna has an overall unit size of 12mm×12mm, consisting of a feeding area, a radiation area, and a matching area; The feeding area is composed of a 50Ω coaxial line, a signal hole, a lower metal ground, a one-to-two stripline, an upper metal ground with an "I"-shaped seam, two layers of Rogers RT / duroid 6002 dielectric plates, and a middle bonding sheet; wherein the 50Ω coaxial line serves as a signal input channel, the signal hole transmits current to the stripline, the stripline realizes impedance conversion by one-to-two splitting, the lower metal ground and the metal shielding tape play the role of shielding and grounding, and the upper metal ground with an "I"-shaped seam is used to couple the signal upward to the radiation area; The radiation zone is composed of a lower metal radiation layer 1 with a cut angle, an upper metal radiation layer 2 with a cut angle, a dielectric layer 2 between the metal radiation layers 1 and 2, and a dielectric layer 1 between the upper metal ground and the lower metal radiation layer 1; wherein the metal radiation layer 1 and the metal radiation layer 2 interact with each other through the dielectric layer in the middle to generate a dual-frequency resonance mode to achieve signal radiation; The matching area is composed of a matching dielectric layer and a foam layer, wherein the matching dielectric layer is used to adjust the matching characteristics of the antenna, and the foam layer is used to adjust the distance between the matching layer and the metal radiation layer; The wide bandwidth and angular scanning design of the X-band stacked phased array antenna is used to achieve the impedance matching performance of the phased array antenna at different scanning angles, with the difference between the normal standing wave ratio and the target value 2 (f FX =VSWR-2), the difference between the E-surface scanned to 60° and the target value of 2.5 (f E =VSWR-2.5), the difference between the VSWR value (f) and the target value (2.5) when the H plane is scanned to 60° H =VSWR-2.5) is the minimum weighted sum as the objective function. At the same time, the parameters that have a significant impact on the radiation mechanism and impedance matching characteristics of the antenna are selected, including the dielectric constant (ε r1 ) and thickness (h1), foam layer thickness (h foam ), the dielectric constant of the radiation zone dielectric layer 1 (ε r2 ) and thickness (h2), dielectric constant of dielectric layer 2 (ε r3 ) and thickness (h3), the size of metal radiation layer 1 (x1, y1), the size of metal radiation layer 2 (x2, y2), etc. are used as design variables, and the section height H (<10mm) is used as a constraint to establish the following optimization model: The antenna is processed by powder 3D printing technology, and the material is nylon PA12. The waveguide method is used to test the solid sample to obtain the specific values ​​of dielectric constant 2.45 and dielectric loss 0.

017. Considering that the minimum size that can be achieved by 3D printing is 0.5mm, the lower bound lb of the above optimization model can be determined as [1,1,1,1,1,1,1,7,8,4,7], and the upper bound ub =[2.45,3,3,2.45,3,2.45,3,9,10,6,9], and take its initial value as X initial =[2.45,2,2,2.45,2,2.45,2,8,5,8], the performance simulation is carried out by high-frequency simulation software HFSS, and the optimization model is solved by Matlab-HFSS-API combined with genetic algorithm, and the optimal solution is X=[1.9,1.77,2.21,1.49,2.53,1.57,2.20,7.85,9.23,4.71,7.90]. At this time, the normal VSWR is less than 2, the E-plane scan to 60° VSWR is less than 2.5, and the H-plane scan to 60° VSWR is less than 2.5; The dielectric layer design is based on the optimal solution of the above optimization, and the following optimization model is established to design a dielectric layer with specific dielectric properties: Among them, χ is the optimization variable, lb is its lower bound, and ub is its upper bound; f εr is the equivalent dielectric constant of the dielectric layer composed of a unit cell, f goal is the optimal value of the dielectric layer parameters.

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