An amplitude and phase weighted series-fed microstrip antenna array

Abstract

The application discloses a phase-amplitude weighted series-fed microstrip antenna array, which comprises an antenna including a dielectric substrate, a microstrip radiation layer printed on the upper surface of the dielectric substrate and a ground plane layer printed on the lower surface of the dielectric substrate; the microstrip radiation layer comprises a patch unit, a transmission feed line structure between the patch units and a feed structure; the patch unit is a rectangular microstrip patch 2; the patch unit generates radiation, and the array amplitude weighting is realized by adjusting the width of the patch unit; the transmission feed line connects the patch units together, and the phase weighting is realized by adjusting the length. Advantage: the application introduces phase weighting to increase the design freedom of the antenna array, effectively improves the limitation of the limited change range of the microstrip patch width, makes the shaping more flexible, and is suitable for arbitrary shape beam shaping.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, and specifically relates to an amplitude-phase weighted series-fed microstrip antenna array. Background Technology

[0002] Beamforming is an important antenna technology widely used in various scenarios such as missile guidance, radar tracking, microwave landing, and environmental monitoring. For example, in airborne radar systems, low-sidelobe antennas are used to avoid signal interference from ground clutter; in automatic radar tracking systems, the antenna's radiating beam needs to be as narrow as possible and have good directivity; when designing air-to-ground search radar, cosecant square antennas are used to ensure that the radiation pattern has narrow beam characteristics in the horizontal direction and a cosecant square beam in the vertical direction, thus ensuring that the received signal strength is independent of the target distance and is only affected by altitude. Based on these advantages, the application scope of antenna array shaping technology in remote sensing, communications, and military fields is constantly expanding, and related technical work is continuously advancing.

[0003] Antenna array feeding methods are mainly divided into three types: series, parallel, and a combination of series and parallel. With the continuous evolution of mobile communication systems, application devices are becoming increasingly miniaturized. Parallel feeding structures occupy a large space, and the use of long feed lines reduces radiation efficiency. Series feeding, on the other hand, has significant advantages in terms of simple structure and low loss, making the design and research of compact series antenna arrays essential. However, the design of series-fed microstrip antenna arrays often only uses the amplitude-weighted method. Although a specific beam can be obtained by adjusting the excitation amplitude of the antenna array, some beams have relatively large amplitude dynamic range requirements, which are difficult to achieve. Furthermore, when higher beam performance requirements are needed, amplitude-weighted antenna arrays alone sometimes cannot meet the requirements.

[0004] In summary, designing a series-fed antenna with amplitude and phase weighting and proposing a precise and efficient shaped series-fed antenna array has significant research value and wide application potential. Summary of the Invention

[0005] The purpose of this invention is to provide an amplitude-phase weighted series-fed microstrip antenna array that achieves precise beamforming and diverse beamforms.

[0006] The technical solution to achieve the purpose of this invention is as follows: an amplitude-phase weighted series-fed microstrip antenna array, comprising a dielectric substrate, a microstrip radiating layer covering the top surface of the dielectric substrate, and a ground plane layer covering the bottom surface of the dielectric substrate; the microstrip radiating layer includes a plurality of microstrip patches, a transmission feed line connecting two adjacent microstrip patches, and a feeding structure arranged on the transmission feed line, all microstrip patches being arranged sequentially from one end to the other along the length direction of the dielectric substrate to form an antenna array; the antenna array is symmetrically arranged on both sides of the transmission feed line located at the middle position; a feeding structure is arranged within the antenna array, the feeding structure being arranged on a transmission feed line located at the middle position of the antenna array, the lengths of the transmission feed line from the two ends of the feeding structure to the two microstrip patches are unequal, and the difference in length needs to achieve a 180° phase difference; the microstrip patches in the antenna array are excited to generate radiation, and the array amplitude weighting is achieved by adjusting the width of the microstrip patches; the transmission feed line in the antenna array connects the microstrip patches, and the array phase weighting is achieved by adjusting the length of the transmission feed line.

[0007] A further preferred embodiment of the technical solution of the present invention is that the amplitude weighting method of the antenna array is as follows: the width of the microstrip patch is assigned a value proportionally according to the normalized amplitude ratio.

[0008] A further preferred embodiment of the technical solution of the present invention is a U-shaped transmission feeder. The U-shaped structure of the transmission feeder ensures equal spacing between array elements while reducing the antenna aperture and avoiding the introduction of grating lobes.

[0009] In a further preferred embodiment of the technical solution of the present invention, the phase weighting of the antenna array is achieved by adjusting the length of the U-shaped transmission feeder, specifically as follows:

[0010] The microstrip radiation layer is divided into several analysis modules, which are the same as the number of array elements. The analysis modules are symmetrically arranged on both sides of the transmission feeder located in the middle position. The analysis modules on one side of the transmission feeder are defined from the middle outward as analysis module 1, analysis module 2, ..., analysis module i, where i is a positive integer, i = N / 2, and N is the number of array elements.

[0011] The phase of each analysis module is determined by the size of the microstrip patch and the length of the U-shaped transmission feeder. The phase value of each analysis module is read using the phase extraction model in the array.

[0012] When the target phase in the antenna array is respectively The phases required for each analysis module from the center outwards are as follows:

[0013] With the size of the fixed microstrip patch unchanged, the length of the U-shaped transmission feeder is adjusted, and each analysis module obtains the required phase.

[0014] In a further preferred embodiment of the technical solution of the present invention, a coaxial cable is used for the power supply structure, and a circular metal plate is loaded above the probe of the coaxial cable to adjust the impedance matching; the length difference between the two microstrip lines connected to the probe is adjusted so that the patches on the left and right sides are excited in phase.

[0015] In a further preferred embodiment of the technical solution of the present invention, slots are made on two microstrip patches close to the feed structure on the antenna array, and the two ends of the U-shaped transmission feed line located in the middle are inserted into the slots. The slots help adjust the sidelobe performance of the antenna.

[0016] An optimization method for arbitrary amplitude and phase of an amplitude-phase weighted series-fed microstrip antenna array includes the following steps:

[0017] S1. Establish a coarse model: Given the number of array elements N and the element spacing 0.5λ, calculate the antenna pattern using the following formula:

[0018]

[0019] S2. Obtain the optimal solution of the coarse model: Using an optimization algorithm, optimize the amplitude and phase of the array elements to make the coarse model generate the target radiation pattern. This amplitude and phase data is the optimal solution of the coarse model.

[0020] S3. Establish a detailed model: Use the antenna model in the full-wave simulation software as the detailed model;

[0021] S4. Parameter extraction: Using optimization algorithms, the results of the coarse model are made to approximate the results of the fine model, and the amplitude and phase of the array elements in the coarse model are obtained;

[0022] S5. Update the Jacobian matrix and obtain the new fine model design parameters. Substitute them into the fine model for simulation verification. If the fine model response still does not meet the design specifications, repeat the iteration until the fine model response meets the design specifications.

[0023] Compared with the prior art, the significant advantages of this invention are:

[0024] 1. This invention introduces phase weighting to increase the design freedom of antenna arrays, effectively improving the limitation of the limited range of microstrip patch width variation, making beamforming more flexible and applicable to beamforming of arbitrary shapes.

[0025] 2. This invention utilizes a spatial mapping algorithm to establish coarse and fine models, and then employs an optimization algorithm to establish the connection and mapping relationship between these two models, thereby performing optimized design. The artificial bee colony algorithm is an intelligent algorithm that fits the parameters of the coarse model to correspond with the radiation pattern of the fine model, thereby establishing the mapping relationship between the coarse and fine models. This invention combines the spatial mapping algorithm and intelligent algorithm to optimize the array, transforming the complex and irregular physical size optimization problem into an iterative weighted value optimization problem, effectively improving antenna shaping performance, and requiring fewer full-wave simulations and achieving high design efficiency.

[0026] 3. In this invention, the transmission feeder adopts a U-shaped structure, and the spacing between adjacent array elements is fixed at half a wavelength, which effectively utilizes the compact characteristics of the series feed array structure, resulting in high space utilization and high antenna radiation efficiency.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0028] Figure 1 This is a structural diagram of the microstrip antenna array in Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of the phase extraction model structure of the array feeder in Embodiment 1 of the present invention;

[0030] Figure 3 This is a comparison diagram of the initial response radiation pattern of the microstrip antenna array in Embodiment 1 of the present invention with the ideal case.

[0031] Figure 4 This is the first iteration response pattern of the microstrip antenna array in Embodiment 1 of the present invention, showing a comparison between the response changes and the ideal situation;

[0032] Figure 5 This is the response pattern of the microstrip antenna array in the second iteration of Embodiment 1 of the present invention, showing a comparison between the response changes and the ideal situation;

[0033] Figure 6 This is a structural diagram of an arbitrary amplitude and phase weighted antenna array in Embodiment 2 of the present invention;

[0034] Figure 7 This is a comparison diagram of the initial response radiation pattern of the arbitrary amplitude and phase weighted antenna array in Embodiment 2 of the present invention with that of the ideal case;

[0035] Figure 8 This is a comparison diagram of the response changes of the arbitrary amplitude and phase weighted antenna array in the first iteration of Embodiment 2 of the present invention with the ideal situation;

[0036] Figure 9 This is a comparison diagram of the response changes of the arbitrary amplitude and phase weighted antenna array in the second iteration of Embodiment 2 of the present invention with the ideal situation;

[0037] Figure 10 This is a comparison diagram of the response changes of the arbitrary amplitude and phase weighted antenna array in the third iteration of Embodiment 2 of the present invention with the ideal situation;

[0038] Figure 11 This is a comparison diagram of the response changes of the arbitrary amplitude and phase weighted antenna array in the fourth iteration of Embodiment 2 of the present invention with the ideal situation. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with embodiments and accompanying drawings.

[0040] This embodiment is an amplitude-phase weighted series-fed microstrip antenna array. The antenna includes a dielectric substrate, a microstrip radiating layer printed on the upper surface of the dielectric substrate, and a ground plane layer printed on the lower surface of the dielectric substrate.

[0041] The microstrip radiating layer includes patch units, a transmission feeder structure between patches, and a power supply structure; the patch unit is a rectangular microstrip patch 2; the patch unit generates radiation by power supply, and the array amplitude weighting is achieved by adjusting its width; the transmission feeder connects the patch units, and the phase weighting is achieved by adjusting its length.

[0042] like Figure 1 As shown, an amplitude-phase weighted series-fed microstrip antenna array comprises a dielectric substrate 1, a microstrip radiating layer covering the top surface of the dielectric substrate 1, and a ground plane layer covering the bottom surface of the dielectric substrate 1. The microstrip radiating layer includes a plurality of microstrip patches 2, transmission feed lines 4 connecting adjacent microstrip patches 2, and feeding structures 3 arranged on the transmission feed lines 4. All microstrip patches 2 are arranged sequentially from one end to the other along the length of the dielectric substrate 1 to form an antenna array. The antenna array is symmetrically arranged about two sides of the transmission feed line 4 located in the middle position. A feed structure 3 is arranged within the antenna array. The feed structure 3 is positioned on a transmission feed line 4 located at the center of the antenna array. The lengths of the transmission feed lines 4 from both ends of the feed structure 3 to the two microstrip patches 2 are unequal, and the difference in length needs to achieve a 180° phase difference. The microstrip patches 2 within the antenna array are excited to generate radiation. The array amplitude weighting is achieved by adjusting the width of the microstrip patches 2. The transmission feed lines 4 within the antenna array connect the microstrip patches 2, and the array phase weighting is achieved by adjusting the length of the transmission feed lines 4.

[0043] This embodiment of the amplitude-phase weighted series-fed microstrip antenna array divides the antenna array into several analysis modules, the same number as the array elements, for phase design. In terms of design methodology, it comprehensively utilizes spatial mapping optimization algorithms and intelligent optimization algorithms to achieve accurate and efficient beamforming of the series-fed microstrip antenna array. The amplitude weighting method for the antenna array is as follows: the expected amplitude of each antenna element is normalized, and the width of the microstrip patch element is proportionally assigned according to the normalized amplitude ratio to achieve array amplitude weighting.

[0044] In this embodiment, the phase weighting of the amplitude-phase weighted series-fed microstrip antenna array is achieved by adjusting the length of the U-shaped transmission feed line. The specific method is as follows:

[0045] The microstrip radiating layer is divided into several analysis modules, the same number as the number of array elements. These modules are symmetrically arranged about two sides of the transmission feed line 4 located in the middle. The analysis modules on one side of the transmission feed line 4 are defined from the middle outwards as analysis module 1, analysis module 2, ..., analysis module i, where i is a positive integer, i = N / 2, and N is the number of array elements. The phase of each analysis module is determined by the size of the microstrip patch 2 and the length of the U-shaped transmission feed line. The phase value of each analysis module is read using the array phase extraction model. When the target phase in the antenna array is... The phases required for each analysis module from the center outwards are as follows: With the size of the fixed microstrip patch 2 unchanged, the length of the U-shaped transmission feeder is adjusted, and each analysis module obtains the required phase.

[0046] An optimization method for arbitrary amplitude and phase of an amplitude-phase weighted series-fed microstrip antenna array includes the following steps:

[0047] S1. Establish a coarse model: Given the number of array elements N and the element spacing 0.5λ, calculate the antenna pattern using the following formula:

[0048]

[0049] S2. Obtain the optimal solution of the coarse model: Using an optimization algorithm, optimize the amplitude and phase of the array elements to make the coarse model generate the target radiation pattern. This amplitude and phase data is the optimal solution of the coarse model.

[0050] S3. Establish a detailed model: Use the antenna model in the full-wave simulation software as the detailed model;

[0051] S4. Parameter extraction: Using optimization algorithms, the results of the coarse model are made to approximate the results of the fine model, and the amplitude and phase of the array elements in the coarse model are obtained;

[0052] S5. Update the Jacobian matrix and simultaneously obtain the new fine model design parameters. Substitute these parameters into the fine model for simulation verification. If the fine model response still does not meet the design specifications at this point, repeat the iteration until the fine model response meets the design specifications. The design specifications are: the main lobe ripple is within a set range, and the sidelobe level is below the target value.

[0053] In this embodiment, S1. Coarse model establishment: Specifically, a coarse model is established in the Matlab software system using the array factor method; given the array center frequency, the number of array elements N is even, the array element spacing is 0.5λ, and the array is centrally symmetrical, so only one side of the parameters needs to be designed, with N / 2 elements on one side and a total of N parameters for amplitude and phase; the amplitude and phase values ​​of the coarse model are obtained using the radiation pattern synthesis algorithm, and a set of amplitude and phase parameters that meet the requirements of the ideal radiation pattern design are obtained. This set of parameters is the optimal solution of the coarse model.

[0054] S3. Fine model establishment: Specifically, the dielectric constant and thickness parameters of the substrate are determined based on the center frequency, and the size of a single patch is obtained; a patch unit plus a right-side feed line is regarded as a whole, and the size of each unit is designed separately using the two-port method; the optimal solution of the coarse model is used as the initial design parameters of the fine model, the amplitude distribution is realized based on the width ratio of the microstrip patch, and the phase distribution is realized by the length of the feed line, thus constructing the fine model;

[0055] S4. Parameter Extraction: Specifically, the fine model response is imported into the Matlab software system and divided into two parts: the main lobe region and the side lobe region, for fitting, as follows:

[0056] Range 1 is the sidelobe region, and the threshold Thres1 for the maximum sidelobe level SIL is set to -20; Range 2 is the main lobe region: since the key indicator of the shaped flat-top beam is the fluctuation degree of the main lobe region, the maximum allowable error threshold Thres2 is set to 5; the algorithm iteration logic is that the objective function value continuously decreases, so a positive real value Q is set. i To ensure the function values ​​are positive, Q1 and Q2 are set to 1000 and 500 respectively; the fitting process is divided into two stages:

[0057] Phase 1: Fitting range 1 to ensure the sidelobe level is below the design target Thrs1 = -20. When the maximum sidelobe level SIL decreases below the target Thrs1, proceed to the next phase. The function value f in this phase can be expressed as:

[0058] f = Q1 + SIL, when SIL ≥ Thres1

[0059] Phase Two: Building upon the previous phase, fit the main lobe region of the radiation pattern; obtain the coarse model design parameters x within the main lobe region that closely approximate the response of the fine model. c 0 The approximation degree is determined by the coarse model parameter x.c 0 With fine model parameter x f 0 For the L2 norm determination of the difference vector within the fitting range, f can be expressed as follows:

[0060] f = Q² + ε, when ε ≥ Thrs².

[0061] Example 1

[0062] A flat-top beamforming antenna based on Fourier distribution was designed with a center frequency of 10 GHz. Adjacent array elements have only a 0-degree or 180-degree phase difference, and the array element spacing is 15 mm. It can achieve a flat-top beam with a ripple of no more than 2 dB in the flat-top region and a sidelobe level of less than -20 dB.

[0063] This embodiment is implemented on an F4B substrate with a relative permittivity of 2.65 and a thickness of 0.8 mm.

[0064] In this embodiment, the excitation current distribution is calculated using the Fourier transform method during the flat-top beamforming process. The sidelobe level of the Fourier distribution is set to -25dB, and the number of array elements is set to 8 to obtain the excitation current distribution ratio. Since the array is centrally symmetrical, only the parameter values ​​on one side of the antenna array are listed. The excitation current distribution from both sides of the array towards the center is as follows:

[0065] Excitation current amplitude distribution: 0.21:0.125:0.429:1

[0066] Excitation current phase distribution: pi:pi:0:0

[0067] The corresponding main lobe ripple range is 1.74 dB and the side lobe level is -22.8 dB, which meets the design requirements. Therefore, this distribution is taken as the optimal solution of the coarse model for the design of the flat-top beamforming antenna array.

[0068] See Figure 1 The antenna array is divided into 4 analysis modules. The patch elements are arranged at equal intervals along the Y-axis of the dielectric substrate, with a spacing of 0.5λ between elements. The antenna array is fed by a coaxial cable at the center, and the two patches adjacent to the feeding structure have grooves for adjusting the impedance.

[0069] See Figure 2 The phase extraction model in the array is structured as follows: a transmission line is connected to each side of the microstrip patch cell. The right-side transmission line has a U-shaped structure, with two ports 6 connected to its two ends. One port powers the cell, while the other serves only as a structure for observing cell performance. Using the port deembed function, the position of any port is moved to the edge of the patch radiation edge, and the phase between port 1 and port 2 is observed.

[0070] The initial dimensional parameters of the detailed model of the antenna array are shown in Table 1.

[0071] Table 1 Initial values ​​of the center-fed antenna array structure (mm)

[0072]

[0073]

[0074] See Figure 3 Full-wave simulation of the antenna array was performed to obtain the initial detailed model response of the antenna, and compared with the ideal radiation pattern. The main lobe fluctuation reached 3.67dB, which is far from meeting the target requirements, and the side lobe level was significantly increased, requiring optimization and iteration.

[0075] Table 2 shows the excitation amplitude distribution and microstrip patch width values ​​obtained in each iteration.

[0076] Table 2. Parameter sets for the coarse and fine models of the Fourier weighted antenna array

[0077]

[0078] See Figure 4 and Figure 5 As shown, after two optimizations, the main lobe ripple gradually flattens out, and the final fluctuation range of the main lobe region is within 1.79dB, which highly coincides with the target radiation pattern. The main lobe beamwidth is 47°, and the sidelobe level is reduced to -20.38dB, all of which meet the design requirements. The 3dB beamwidth is 45.8°, the antenna gain is 16.5dB, and the antenna radiation performance is good.

[0079] Example 2

[0080] This embodiment introduces an arbitrary phase parameter, expanding the array design freedom, effectively reducing the pressure on the excitation amplitude ratio, and making beamforming more flexible. This embodiment ultimately achieves beam top ripple within 0.69 dB.

[0081] Artificial bee colony algorithm is used for pattern synthesis. The iterative logic is to obtain the minimum objective function value. The smaller the objective function value, the closer the corresponding pattern function is to the solution objective. Since flat-top beamforming focuses more on the main lobe ripple, this paper follows the incremental optimization principle and divides the optimization process into two stages: first, the sidelobe region is optimized until the sidelobe level is below a threshold; then, the main lobe region of the pattern is optimized, and the main lobe ripple level is reduced through continuous optimization iterations until the maximum number of iterations is reached. The synthesized results show that the main lobe ripple of the flat-top beam is within 0.34dB, the sidelobe level is below -18.3dB, and the excitation current distribution from both sides of the array to the center is as follows:

[0082] Amplitude distribution: 0.1:0.1618:0.2:0.3088:0.2:1

[0083] Phase distribution: 0.495:1.187:1.187:2.85:0:0

[0084] See Figure 6 Based on the above excitation current distribution, a 1×12 linear array was designed, using the same design method as in Example 1. Full-wave simulation was performed on the designed antenna array, and the initial fine model response was obtained (see [example code]). Figure 7 The main lobe region fluctuated by more than 5 dB, which is significantly different from the ideal pattern.

[0085] Table 3 shows the initial fine model size parameters.

[0086] Table 3 Initial values ​​(mm) for arbitrary amplitude and phase weighted antenna array structure

[0087] <![CDATA[w1]]> <![CDATA[w2]]> <![CDATA[w3]]> <![CDATA[w4]]> <![CDATA[w5]]> <![CDATA[w6]]> cen_h 0.88 1.423 1.76 2.64 1.32 8.8 9.5 <![CDATA[l1]]> <![CDATA[l2]]> <![CDATA[l3]]> <![CDATA[l4]]> <![CDATA[l5]]> <![CDATA[l6]]> rr 10.4 10 9.85 9.6 9.852 8.9 0.6 <![CDATA[I_bu1]]> <![CDATA[I_bu2]]> <![CDATA[I_bu3]]> <![CDATA[I_bu4]]> <![CDATA[I_bu5]]> lx III 6.8 0 3.7 4.4 0 0.3 3.6

[0088] After four spatial mapping iterations, precise flat-top beamforming was obtained. The pattern changes during the iteration process are shown in [the diagram]. Figure 8 , 9 10 and 11 Figure 8 It can be seen that after the first iteration, the main lobe region of the response pattern is significantly improved compared with the initial simulation results, and the ripple level is above -2.5dB. Figure 9 Compared with the previous simulation, the main lobe performance has also been significantly improved. Figure 10 as well as Figure 11 It can be seen that the sidelobe characteristics of the radiation pattern have been improved. In addition, the first three iterations were based on the error of excitation phase weighting to optimize the feed line size between fine model elements, and the last optimization was for the array element amplitude, resulting in an excitation amplitude distribution of 0.1:0.1618:0.2:0.308:0.25:1. Figure 11 For the final simulation results, the main lobe ripple of the flat-top beam is reduced to within -0.69dB, and the level in the sidelobe region reaches -11.86dB. The excellent flat-top beamforming verifies the feasibility of realizing arbitrary amplitude and phase schemes in microstrip series-fed antenna arrays and the accuracy and efficiency of the method.

[0089] The coarse model parameter set and the fine model parameter set during the phase iteration process are shown in Table 4 and Table 5, respectively.

[0090] Table 4 Coarse Model Parameter Set

[0091] Phase distribution / rad First iteration Second iteration Third iteration 1 0.481 0.458 0.437 2 0 0 0 3 1.13 0.985 0.95 4 2.7 2.9 2.82 5 0 0 0 6 0 0 0

[0092] Table 5 Parameter Set for Detailed Model

[0093]

[0094] The above content shows and describes the basic principles and main features of this design method. Besides the embodiments described above, this invention can also be implemented in other ways. Any technical solution formed by equivalent substitution or transformation that does not require creative effort is within the scope of protection claimed by this invention.

Claims

1. A phase-weighted series-fed microstrip antenna array, characterized in that, The antenna array includes a dielectric substrate (1), a microstrip radiating layer covering the top surface of the dielectric substrate (1), and a ground plane layer covering the bottom surface of the dielectric substrate (1). The microstrip radiating layer includes a plurality of microstrip patches (2), a transmission feed line (4) connecting two adjacent microstrip patches (2), and a feeding structure (3) arranged on the transmission feed line (4). All microstrip patches (2) are arranged one by one from one end to the other along the length direction of the dielectric substrate (1) to form an antenna array. The antenna array is symmetrically arranged on both sides of the transmission feed line (4) located in the middle position. A feeding structure (3) is arranged in the antenna array. The feeding structure (3) is arranged on a transmission feed line (4) located in the middle position of the antenna array. The transmission feed lines (4) between the two ends of the electrical structure (3) and the two microstrip patches (2) are of unequal length, and the difference in length needs to achieve a 180° phase difference; the transmission feed line (4) is a U-shaped transmission feed line; the microstrip patches (2) in the antenna array are excited to generate radiation, and the array amplitude weighting is achieved by adjusting the width of the microstrip patches (2); the amplitude weighting method of the antenna array is: the width (2) of the microstrip patch is assigned a value proportionally according to the normalized amplitude ratio; the transmission feed lines (4) in the antenna array connect the microstrip patches (2), and the phase weighting of the array is achieved by adjusting the length of the transmission feed line (4); the phase weighting of the antenna array is achieved by adjusting the length of the U-shaped transmission feed line, and the specific method is: The microstrip radiation layer is divided into several analysis modules with the same number of array elements. The analysis modules are symmetrically arranged on both sides of the transmission feed line (4) located in the middle position. The analysis modules on one side of the transmission feed line (4) are defined from the middle outward as analysis module 1, analysis module 2, ... analysis module i, where i is a positive integer, i=N / 2; N is the number of array elements. The phase of each analysis module is determined by the size of the microstrip patch (2) and the length of the U-shaped transmission feeder. The phase value of each analysis module is read using the phase extraction model in the array. When the target phases in the antenna array are [φ1, φ2, φ3, φ4, …φi], the phases that each analysis module needs to achieve from the center outwards are: [φ1-φ2, -(φ1-φ2)+(φ2-φ3), -(φ2-φ3)+(φ3-φ4), -(φ3-φ4)+(φ4-φ5), …]; With the size of the fixed microstrip patch (2) unchanged, the length of the U-shaped transmission feeder is adjusted, and each analysis module obtains the required phase; The feeding structure (3) uses a coaxial cable. A circular metal plate is loaded above the probe of the coaxial cable to adjust the impedance matching. The length difference between the two microstrip lines connected to the probe is adjusted so that the patches on the left and right sides are excited in phase. The antenna array has slots (5) on the two microstrip patches (2) close to the feeding structure (3), and the two ends of the U-shaped transmission feed line located in the middle position are inserted into the slots (5).

2. The method for optimizing the arbitrary amplitude and phase of an amplitude-phase weighted series-fed microstrip antenna array according to claim 1, characterized in that, Includes the following steps: S1. Establish a coarse model: Given the number of array elements N and the element spacing 0.5λ, calculate the antenna pattern using the following formula: S2. Obtain the optimal solution of the coarse model: Using an optimization algorithm, optimize the amplitude and phase of the array elements to make the coarse model generate the target radiation pattern. This amplitude and phase data is the optimal solution of the coarse model. S3. Establish a detailed model: Use the antenna model in the full-wave simulation software as the detailed model; S4. Parameter extraction: Using optimization algorithms, the results of the coarse model are made to approximate the results of the fine model, and the amplitude and phase of the array elements in the coarse model are obtained; S5. Update the Jacobian matrix and obtain the new fine model design parameters. Substitute them into the fine model for simulation verification. If the fine model response still does not meet the design specifications, repeat the iteration until the fine model response meets the design specifications.

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