A phased array near-field beam steering method based on focused basis functions

Abstract

The application provides a phased array near-field beam control method based on focusing basis functions, (1) a desired test area is gridded and divided into multiple focusing points; (2) focusing basis functions are obtained by the focusing points, and new array element amplitude and phase distributions are obtained; (3) the obtained amplitude and phase distributions are brought into a phased array, and the field strength of the test area is calculated; (4) the field strengths of the focusing points of the test area and the expected field strength are compared, and new amplitude and phase distributions are obtained again; (5) steps (3) to (4) are repeated until the uniformity of the field strength of the test area meets the requirements, and the array element amplitude and phase at this time are recorded as the optimal distribution; this method can synthesize a phased array of a given size, obtain the feeding amplitude and phase item distribution, and thus generate a near-field focusing beam with high intensity (greater than 1000 V / m ), a wide range (more than 1m), and good field uniformity (less than 1dB) in the near-field area of the phased array, so as to meet the test requirements in the electromagnetic compatibility field.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and more specifically to a near-field beam control method for a phased array antenna. Background Technology

[0002] With the rapid advancement of military informatization and the increasingly fierce electronic warfare on the modern battlefield, the external radio frequency electromagnetic environment on the battlefield has become more intense and complex. The effects of the electromagnetic environment on weapons and equipment are becoming increasingly significant, and electromagnetic incompatibility issues are constantly emerging, becoming one of the key factors restricting combat effectiveness and even determining the success or failure of war. It is necessary to conduct in-depth research on external radio frequency electromagnetic environment sensitivity testing technology to provide experimental capabilities for the evaluation of electromagnetic environment effects on weapons and equipment.

[0003] With the successive release of GJB1389A "System Electromagnetic Compatibility Requirements" and GJB 8848-2016 "System Electromagnetic Environment Effect Test Methods", the scope of external radio frequency electromagnetic environment sensitivity testing has been gradually expanded to large system-level test objects such as aircraft and missiles. In the field of military electromagnetic compatibility testing, the requirements for the electromagnetic field generated by the transmitting source are becoming increasingly stringent. The transmitting source needs to generate a beam with a voltage of up to several thousand volts per meter (greater than 1000 V / m), a beamwidth of more than 1m, and good field uniformity (less than 1 dB) in the near field region.

[0004] Phased array antennas, with their high gain, easy beamforming, and fast scanning capabilities, are widely used in radar, astronomy, and communications. They are the most promising technology for achieving this test field. However, current reports on phased arrays mostly focus on far-field beamforming, and the beamwidth is relatively narrow, resulting in poor field uniformity in the test area (greater than 3dB), which cannot meet the requirements of military electromagnetic compatibility testing. Summary of the Invention

[0005] This invention provides a phased array near-field beam control method based on focusing basis functions, comprising the following steps:

[0006] (1) The expected test area is gridded and divided into multiple focal points;

[0007] (2) Using the spatial location of the focal point as the focusing target, determine the amplitude and phase distribution of each element of the phased array, which serves as the focusing basis function for that focal point;

[0008] (3) Iterate through all the focal points in sequence to obtain a set of focal basis functions. Set the initial weight of each focal basis function to 1 and sum them to obtain a new array element amplitude and phase distribution.

[0009] (4) Substitute the obtained amplitude and phase distribution into the phased array to calculate the field strength in the test area;

[0010] (5) Compare the field strength and expected field strength of each focal point in the test area. For focal points with a field strength higher than the expected field strength, decrease their basis function weights and for focal points with a field strength lower than the expected field strength, increase their basis function weights.

[0011] (6) Summing the basis functions with the new weights yields a new amplitude-phase distribution;

[0012] (7) Repeat steps (4) to (6) until the field strength uniformity in the test area meets the requirements. The amplitude and phase of the array elements at this time are recorded as the optimal distribution.

[0013] Preferably, step (1) includes: the phased array is an M×N rectangular array distributed along the xoy plane, and the coordinates of each array element are (x mn ,y mn The test area is a rectangle of size a × b, located in the z = R plane. The phased array can generate a rectangular focal spot with good field uniformity in the test area, with an upper limit of field strength E. max The lower limit is E min The grid spacing of the test area is equal to the half-width of the phased array focused beam, i.e., the formula is:

[0014]

[0015] In the formula:

[0016] D—grid spacing,

[0017] R—the distance between the test area and the phased array surface.

[0018] λ—wavelength

[0019] d—Phase array element spacing,

[0020] Rounding up D from formula (1) gives D0, which is used as the actual grid spacing. For an a×b rectangle, the coordinates of the focal point are:

[0021]

[0022] In the formula: I = a / D0 + 1; J = b / D0 + 1.

[0023] Preferably, step (2) includes: focusing on the focal point P i,j (coordinate x) i,j ,y i,j ,z i,j The phased array amplitude distribution uses a cosine distribution to reduce sidelobes. The amplitude calculation formula is as follows:

[0024]

[0025] The formula for calculating amplitude and phase distribution is as follows:

[0026]

[0027] In the formula:

[0028] k—space wavenumber, k=2π / λ, ∠—obtaining the complex angle, sequentially assigning coordinates (x, y) to each array element. mn ,y mn Substituting ,0) into formula (4), we can obtain the focal point P. i,j Phase distribution of phase array A i,j (A i,j Given an M×N matrix, matrix element a mn ).

[0029] Preferably, step (3) includes: sequentially focusing each focal point P i,j Substituting into formula (4), we obtain the phase distribution of the phased array corresponding to different focal points, which serves as a set of focusing basis functions A. i,j (1≤i≤I, 1≤j≤J); Setting the initial weight of each focal point to 1, then the matrix elements B of the weight matrix B... i,j All are 1. Summing the focusing basis functions yields the new array element amplitude and phase distribution A0.

[0030]

[0031] Preferably, step (4) includes: inputting the amplitude and phase distribution A0 of the new array element into the phased array, and calculating the P at each observation point in the test area. i,j The electric field level E generated (the coordinates of the focal point can be directly used as the coordinates of the observation point) t Use the following calculation formula:

[0032]

[0033] In the formula:

[0034] η—Spatial wave impedance, η=120π,

[0035] —The angle between the test area observation point and the antenna array element —The distance between the test point and the antenna array element in the test area, Δx=x mn -x ij Δy=y mn -y ij Δz=R,

[0036] —The distance between the test area observation point and the antenna array element.

[0037] G(θ) — the antenna radiation pattern of the array element, which is a function of the included angle θ.

[0038] P mn =|A0| mn —Element feed amplitude,

[0039] —Element feed phase.

[0040] Further, step (5) includes: applying the field strength E calculated in step (4) to... t0 (x i,j ,y i,j The basis function weight matrix B is adjusted by comparing the field strength (R) with the expected field strength in the test area. For points exceeding the upper limit of the expected field strength, the basis function weight B corresponding to that focal point is reduced. i,j For points below the lower limit of the desired field strength, increase the basis function weight B corresponding to that focal point. i,j The new weight matrix is ​​denoted as B1.

[0041] Further, step (6) includes: substituting the updated basis function weights B1 into formula (5) to calculate the new array element amplitude and phase distribution A1.

[0042] Further, step (7) includes: substituting A1 into formula (6) to calculate the new field strength distribution E in the test area. t1 (x i,j ,y i,j The electric field strength (R) is compared with the expected electric field strength again. The basis function weight matrix B is adjusted, and steps (4) to (6) are repeated until the electric field strength E in the test area is reached. t (x i,j ,y i,j If all values ​​(R) fall within the desired field strength range, substitute the basis function weight matrix at this time into formula (4) to obtain the phase distribution of the phased array, which is the final distribution. After obtaining the final field strength of the test area, calculate the field uniformity according to the following formula:

[0043] Ep = 20(lg(E) max )-lg(E min (7)

[0044] In the formula:

[0045] E max —Maximum electric field strength within the test area, V / m

[0046] E min —Minimum electric field strength within the test area, V / m.

[0047] Technical effect

[0048] This technical solution proposes a phased array near-field beam control method based on focusing basis functions. It can synthesize a phased array of a given size to obtain its feed amplitude and phase term distribution, thereby generating a high-intensity (greater than 1000V / m), wide-range (greater than 1m), and good field uniformity (less than 1dB) near-field focused beam in the near-field region of the phased array, which meets the testing requirements in the field of electromagnetic compatibility. Attached Figure Description

[0049] Figure 1 Schematic diagram of phased array and test area

[0050] Figure 2 Example 1: Phased Array Amplitude Distribution

[0051] Figure 3 Example 1: Phase Distribution of Phased Array

[0052] Figure 4 Example 1: Field Distribution in the Test Area

[0053] Figure 5 Example 1: Phased Array Amplitude Distribution

[0054] Figure 6 Example 1: Phase Distribution of Phased Array

[0055] Figure 7 Example 1: Field distribution of the test area (front view)

[0056] Figure 8 Example 1: Field distribution in the test area (side view)

[0057] Figure 9 Example 1: Field distribution of the test area (front view)

[0058] Figure 10 Example 1: Field distribution in the test area (side view)

[0059] Figure 11 Example 1: Field distribution of the test area (front view)

[0060] Figure 12 Example 1: Field distribution in the test area (side view)

[0061] Figure 13 Example 1: Phased Array Amplitude Distribution

[0062] Figure 14 Example 1: Phase Distribution of Phased Array

[0063] Figure 15 Example 2: Field distribution in the test area (front view)

[0064] Figure 16 Example 2: Field distribution of the test area (side view)

[0065] Figure 17 Example 2 Phased Array Amplitude Distribution

[0066] Figure 18 Example 2: Phase Distribution of Phased Array

[0067] Figure 19 Example 3: Field distribution of the test area (front view)

[0068] Figure 20 Example 3: Field distribution in the test area (side view)

[0069] Figure 21 Example 3 Phased Array Amplitude Distribution

[0070] Figure 22 Example 3: Phase Distribution of Phased Array Specific Implementation Method 1

[0072] The frequency f0 is set to 6 GHz; the phased array size (M×N) is 50×50; the antenna element spacing is 50 mm; the antenna element gain is 4.385 dBi (gain linearity 2.745); and the antenna element radiation pattern is as follows.

[0073] G(θ) = 2.745cos 2.15 (θ)

[0074] Phased array and test area such as Figure 1 As shown; test area distance: 2m, test area size: 1.5m×1.5m, test area field strength requirement: 4000V / m~4200V / m; that is, to find the phase distribution of the phased array, and generate a uniform field of 4000V / m~4200V / m with a focal spot range of 1.5m×1.5m at R=2m.

[0075] The test area is gridded, with a beamwidth of [value missing].

[0076]

[0077] Rounding up, we get a grid spacing D = 0.02. Given the test area a = b = 1.5, the grid size of the test area is I = J = 76, and the focal point coordinates are...

[0078]

[0079] The focal point is a 76×76 rectangular array with an array spacing of 0.02m.

[0080] When i = j = 1, P 1,1 When = (-0.75, -0.75, 2), substitute into the formula.

[0081]

[0082]

[0083] I mn =I m I n

[0084] 1) Calculate the amplitude distribution values ​​of the upper left corner element (m=1, n=1) of the phased array.

[0085]

[0086]

[0087] I 11 =I1I1=0.0039

[0088] 2) Amplitude distribution values ​​of a certain array element (m=10, n=10) in the array

[0089]

[0090]

[0091] I 1010 =I 10 I 10 =0.3978

[0092] 3) Amplitude distribution values ​​of the lower right corner array elements (m=50, n=50)

[0093]

[0094]

[0095] I 5050 =I 50 I 50 =0.0039

[0096] Given the wavenumber k = 2π / 0.05 = 125.75 and P... 1,1 Substituting (-0.75, -0.75, 2) into the formula yields...

[0097]

[0098] Substitute the coordinates (x) of each phased array element in sequence mn ,y mn By calculating the value of P, we can obtain the focus at P. 1,1 The phase distribution of the phased array, the amplitude distribution is as follows Figure 2 As shown, the phase distribution is as follows Figure 3 As shown.

[0099] 1) Calculate the value of the top left element of the phased array (m=1, n=1, then x) 11 =-1.225,y 11 The amplitude and phase distribution values ​​of (z = -1.225, z = 0)

[0100] Δx = -1.225 - (-0.75) = -0.475

[0101] Δy = -1.225 - (-0.75) = -0.475

[0102] Δz=2

[0103]

[0104]

[0105] a 11 =0.0039exp(1.4149j)

[0106] 2) Calculate the value of x for a given element (m = 10, n = 10) in a phased array. 1010 =-0.775,y 1010 The amplitude and phase distribution values ​​of (z = -0.775, z = 0)

[0107] Δx = -0.775 - (-0.75) = -0.025

[0108] Δy = -0.775 - (-0.75) = -0.025

[0109] Δz=2

[0110]

[0111]

[0112] a 1010 =0.3978exp(0.2117j)

[0113] 3) Calculate the lower right corner array element (m=50, n=50, then x) 5050 =1.225,y 5050 The amplitude and phase distribution values ​​of z = 1.225 (z = 0)

[0114] Δx = 1.225 - (-0.75) = 1.975

[0115] Δy = 1.225 - (-0.75) = 1.975

[0116] Δz=2

[0117]

[0118]

[0119] a 5050 =0.0039exp(-1.5484j)

[0120] Substitute the amplitude and phase distribution into the formula

[0121]

[0122]

[0123]

[0124]

[0125] The calculated electric field distribution in the test area is as follows: Figure 4 As shown, the phased array is indeed focused on P. 1,1 = (-0.75, -0.75, 2) points.

[0126] The electric field value at each point in the test area is obtained from the contributions of all elements of the phased array, denoted by point P. 1,1 Taking (-0.75, -0.75, 2) as an example, the calculation process of the electric field value is as follows:

[0127] 1) Calculate the position of the top left element of the phased array (m=1, n=1, then x=-1.225, y=-1.225, z=0) in P. 1,1 Electric field strength at:

[0128] η = 120π = 376.99

[0129] Δx=-1.225-(-0.75)=-0.475m

[0130] Δy=-1.225-(-0.75)=-0.475m

[0131] Δz=2

[0132]

[0133] G(θ) = 2.745cos 2.15 (18.566°) = 2.447

[0134] P 11 =abs(a 11 ) = 0.0039W

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141] 2) Calculate the value of x for a given element (m = 10, n = 10) in a phased array. 1010 =-0.775,y 1010 =-0.775, z=0) in P 1,1 Electric field strength at:

[0142] η = 120π = 376.99

[0143] Δx=-0.775-(-0.75)=-0.025m

[0144] Δy=-0.775-(-0.75)=-0.025m

[0145] Δz=2

[0146]

[0147] G(θ) = 2.745cos 2.15 (1.0128°) = 2.7441

[0148] P 1010 =abs(a 1010 ) = 0.3978W

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155] 3) Calculate the lower right corner array element (m=50, n=50, then x) 5050 =1.225,y 5050 =1.225, z=0) in P 1,1 Electric field strength at:

[0156] η = 120π = 376.99

[0157] Δx = 1.225 - (-0.75) = 1.975m

[0158] Δy = 1.225 - (-0.75) = 1.975m

[0159] Δz=2

[0160]

[0161] G(θ) = 2.745cos 2.15 (54.3952°)=0.8579

[0162] P 5050 =abs(a 5050 ) = 0.0039W

[0163]

[0164]

[0165]

[0166]

[0167]

[0168]

[0169] 4) Calculate the position of all other array elements in P in sequence. 1,1 Electric field strength at:

[0170] 5) Place all array elements in P 1,1 Summing the electric field strength values ​​at each point, we obtain P. 1,1 Total field strength at point

[0171]

[0172]

[0173]

[0174]

[0175] The amplitude and phase distributions corresponding to each focal point need to be calculated sequentially as basis functions, and then summed to obtain a new amplitude and phase distribution. During summation, each element of the initial weight coefficient matrix B of each basis function is 1. Then the new amplitude and phase distribution A0 is as follows: Figure 5 and Figure 6 As shown, substituting A0 into the formula

[0176]

[0177]

[0178]

[0179]

[0180] The obtained field strength distribution is as follows Figure 7 and Figure 8 As shown, the processed field focal spot can cover a test area of ​​1.5m × 1.5m. The highest field strength within the test area is 4348V / m, and the lowest is 2920V / m. Substituting these values ​​into the formula to calculate the field uniformity:

[0181] Ep=20(lg(4348)-lg(2920))=3.04dB

[0182] The field uniformity is relatively poor.

[0183] Will Figure 7 The electric field strength is compared with the expected electric field strength (3600V / m~4300V / m), the weight matrix B is adjusted, and the successive approximation method is used, then:

[0184] 1. For points in the electric field distribution map that are below 3600V / m, add 0.1 to the corresponding focal point basis function weight value;

[0185] 2. For points in the field strength distribution map that are higher than 4300V / m, reduce the corresponding focal point basis function weight value by 0.1.

[0186] Substituting the weight matrix B from the single adjustment into the formula, the new amplitude-phase distribution A1 is calculated; substituting the new amplitude-phase distribution A1 into the formula for recalculation, the highest field strength in the test area becomes 4276 V / m, and the lowest becomes 3217 V / m. Substituting these values ​​into the formula, the field homogeneity is calculated:

[0187] Ep=20(lg(4276)-lg(3217))=2.52dB

[0188] The electric field strength distribution was compared again with the expected electric field strength. After 10 cycles, the highest electric field strength was 4240 V / m, and the lowest was 3602 V / m. The electric field strength in the test area all fell within the range of 3600 V / m to 4300 V / m. At this time, the electric field strength distribution was as follows: Figure 9 and Figure 10 As shown.

[0189] The desired electric field strength in the test area was then set to 4000V / m to 4200V / m, and adjusted 5 times. The electric field strength fell within the range of 4000V / m to 4200V / m, with the highest value being 4198V / m and the lowest value being 4003V / m. The electric field uniformity was then calculated using the formula.

[0190] Ep=20(lg(4198)-lg(4003))=0.43dB

[0191] At this time, the front view and side view of the electric field distribution are as follows: Figure 11 and 12 As shown, the amplitude and phase distribution of the phased array are as follows: Figure 13 and Figure 14 As shown.

[0192] As can be seen, the amplitude and phase distribution obtained by the above algorithm successfully enabled the phased array to generate a uniform field of size 1.5m×1.5m at a distance of 2m. Specific Implementation Method Two

[0194] Using the phased array of Example 1, focal spots of any size smaller than 1.5m × 1.5m can be generated. Taking a size of 0.5m × 0.5m as an example, the performance requirements are as follows:

[0195] 1) Frequency f0 = 6 GHz;

[0196] 2) Phased array size (M×N): 50×50;

[0197] 3) Antenna element spacing: 50mm;

[0198] 4) Test area distance: 2m;

[0199] 5) Test area size: 0.5m × 0.5m;

[0200] 6) Electric field strength requirements for the test area: 4000V / m~4200V / m;

[0201] That is, to determine the phase distribution of the phased array, and to generate a uniform field with a focal spot range of 0.5m × 0.5m and a value of 4000V / m to 4200V / m at z = 2m.

[0202] The steps are similar to those in Example 1, and the resulting uniform field strength distribution front and side views are as follows. Figure 15 As shown in Figure 16, the electric field strength falls within the range of 4000V / m to 4200V / m, with a maximum value of 4195V / m and a minimum value of 4002V / m. Substituting these values ​​into the formula to calculate the field uniformity:

[0203] Ep=20(lg(4195)-lg(4002))=0.41dB

[0204] The field uniformity is 0.41 dB, and the amplitude and phase distribution of the phased array are as follows: Figure 17 and Figure 18 As shown. Specific Implementation Method 3

[0206] The phased array used in Example 1 can generate a field with the same field uniformity, the same focal spot size, and a specified field strength value. Taking an average field strength of 6000V / m to 6300V / m as an example, the performance requirements are as follows:

[0207] 1) Frequency f0 = 6 GHz;

[0208] 2) Phased array size (M×N): 50×50;

[0209] 3) Antenna element spacing: 50mm;

[0210] 4) Test area distance: 2m;

[0211] 5) Test area size: 1.5m × 1.5m;

[0212] 6) Electric field strength requirements for the test area: 6000V / m~6300V / m;

[0213] That is, to determine the phase distribution of the phased array, and to generate a uniform field with a focal spot range of 1.5m × 1.5m and a value of 6000V / m to 6300V / m at z = 2m.

[0214] The steps are similar to those in Example 1, and the resulting uniform field strength distribution front and side views are as follows. Figure 19 As shown in Figure 20, the electric field strength falls within the range of 6000V / m to 6300V / m, with a maximum value of 6297V / m and a minimum value of 6005V / m. Substituting these values ​​into the formula, the field uniformity can be calculated as follows:

[0215] Ep=20lg(6297 / (1μV / m)-6005 / (1μV / m))=0.41dB

[0216] The field uniformity is 0.41 dB, and the amplitude and phase distribution of the phased array are as follows: Figure 21 and Figure 22 As shown.

Claims

1. A phased array near-field beam steering method based on focused basis functions, characterized in that, Includes the following steps: (1) The expected test area is gridded and divided into multiple focal points; (2) Using the spatial location of the focal point as the focusing target, determine the amplitude and phase distribution of each element of the phased array, which serves as the focusing basis function for that focal point; (3) Iterate through all the focal points in sequence to obtain a set of focal basis functions. Set the initial weight of each focal basis function to 1 and sum them to obtain a new array element amplitude and phase distribution. (4) Substitute the obtained amplitude and phase distribution into the phased array to calculate the field strength in the test area; (5) Compare the field strength and expected field strength of each focal point in the test area. For focal points with a field strength higher than the expected field strength, decrease their basis function weights and for focal points with a field strength lower than the expected field strength, increase their basis function weights. (6) Summing the basis functions with the new weights yields a new amplitude-phase distribution; (7) Repeat steps (4) to (6) until the field strength uniformity of the test area meets the requirements. The amplitude and phase of the array elements at this time are recorded as the optimal distribution. Step (1) includes: the phased array is an M×N rectangular array distributed along the xoy plane, and the coordinates of each array element are... ,in The test area is an a×b rectangle, located at... A planar phased array can generate a rectangular focal spot with good field uniformity in the test area, with an upper limit on the field strength. The lower limit is ; The grid spacing of the test area is equal to the half-width of the phased array focused beam, i.e., the formula is: （1） In the formula: D — grid spacing, R — the distance between the test area and the phased array surface. — Wavelength, d — Spacing between phased array elements Rounding up D from formula (1) gives D0, which is used as the actual grid spacing. For an a×b rectangle, the coordinates of the focal point are: （2） In the formula: ; ; Step (2) includes: focusing on the focal point (coordinate The phased array amplitude distribution uses a cosine distribution to reduce sidelobes. The amplitude calculation formula is as follows: （3） The formula for calculating amplitude and phase distribution is as follows: （4） In the formula: — Space wavenumber, ， — Find the complex angle. The coordinates of each array element are sequentially set. Substituting into formula (4), we can obtain the focal point. Phased array amplitude and phase distribution ( For one Matrix, matrix elements ).

2. The phased array near-field beam control method based on focusing basis functions according to claim 1, characterized in that, Step (3) includes: sequentially focusing each focal point Substituting into formula (4), we obtain the phase distribution of the phased array corresponding to different focal points, which serves as a set of focusing basis functions. ( ); if the initial weights of each focal point are set to 1, then the matrix elements of weight matrix B are... All are 1. Summing the focusing basis functions yields the new array element amplitude and phase distribution A0: （5）。 3. The phased array near-field beam control method based on focusing basis functions according to claim 2, characterized in that, Step (4) includes: inputting the amplitude and phase distribution A0 of the new array element into the phased array, and calculating the amplitude and phase distribution at each observation point in the test area. The generated electric field level E t Use the following calculation formula: （6） In the formula: — Spatial wave impedance, , — The angle between the test area observation point and the antenna array element. — The distance between the test area observation point and the antenna array element. , , , — The distance between the test area observation point and the antenna array element. — The radiation pattern of the array element antenna is the included angle. The function, — Array element feed amplitude, — Array element feed phase.

4. The phased array near-field beam control method based on focusing basis functions according to claim 3, characterized in that, Step (5) includes: calculating the field strength in step (4). Compared with the expected field strength in the test area, the basis function weight matrix B is adjusted. For points exceeding the upper limit of the expected field strength, the basis function weights corresponding to those focal points are reduced. For points below the lower limit of the desired field strength, increase the weight of the basis function corresponding to that focal point. The new weight matrix is ​​denoted as B1.

5. The phased array near-field beam control method based on focusing basis functions according to claim 4, characterized in that, Step (6) includes: substituting the updated basis function weights B1 into formula (5) to calculate the new array element amplitude and phase distribution A1.

6. The phased array near-field beam control method based on focusing basis functions according to claim 5, characterized in that, Step (7) includes: substituting A1 into formula (6) to calculate the new field strength distribution in the test area. The field strength is compared again with the expected field strength, the basis function weight matrix B is adjusted, and steps (4) to (6) are repeated until the field strength in the test area is reached. All fall within the desired field strength range. Substituting the basis function weight matrix at this point into formula (4), the phase distribution of the phased array is obtained as the final distribution. After obtaining the final field strength of the test area, the field uniformity is calculated according to the following formula: （7） In the formula: —Maximum electric field strength within the test area, V / m —Minimum electric field strength within the test area, V / m.

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