A frequency-controlled array time-varying receiving beamforming method

Abstract

The present application discloses a method for forming a time-varying receiving beam of a frequency-controlled array, the method comprising: calculating a time-varying receiving beam weight vector according to the frequency-controlled array transmitting beam within a preset main lobe space range; discretizing the time-varying receiving beam weight vector to determine a segmented time-varying receiving beam discrete weight vector; calculating a receiving beam optimization weight vector corresponding to the maximum receiving time-varying beam energy of the frequency-controlled array within the area coefficient range according to the area coefficient of the desired beam coverage area; calculating a time-varying radiation pattern of the frequency-varying receiving beam of the frequency-controlled array according to the segmented time-varying receiving beam discrete weight vector, the receiving beam optimization weight vector and the receiving array steering vector. The technical solution in the present application solves the problem of matching the receiving beam with the transmitting beam, and by designing the time-varying receiving beam weight vector and the receiving beam optimization weight vector, the time-varying receiving beam of the receiving element of the frequency-controlled array is obtained, thereby enhancing the control of the receiving beam radiation pattern of the frequency-controlled array.

Description

Technical Field

[0001] The present application relates to the technical field of frequency-controlled array receive beamforming, and in particular to a frequency-controlled array time-varying receive beamforming method. Background Art

[0002] The frequency-controlled array has a beam that is related to the distance and angle, which brings richer signal information. The current methods for dealing with the frequency-controlled array receive beamforming problem include: Xu Jingwei et al. proposed frequency-controlled array receive beamforming in "Receive beamforming of frequencydiverse array radar systems", which established a mathematical model of receive beamforming in frequency-controlled array radar systems; WANG Bo et al. proposed a receiver adaptive beamforming method in "Beamforming analysis based on CSB sin-FDA", which effectively formed the main lobe at the target position; Xu Yanhong et al. proposed a joint transmit-receive beamforming method in "Enhanced Transmit-Receive Beamforming for Frequency Diverse Array", which can form a point beam. The receive beam weight vectors of the above methods are all time-invariant vectors. However, this type of frequency-controlled array receive beam velocity technology corresponds to a time-invariant vector.

[0003] However, in the prior art, the time-varying nature of the frequency-controlled array transmit beam cannot be matched due to the use of a time-invariant receiving weight vector. In order to enhance the control of the receiving beam pattern and quickly match the receiving beam with the transmitting beam, it is necessary to perform time-varying control on the receiving array elements of the frequency-controlled array, design a time-varying receiving weight vector according to the time-varying law of the frequency-controlled array transmit beam, achieve matching between the frequency-controlled array receive beam and the frequency-controlled array transmit beam, improve the distance angle coverage area of ​​the frequency-controlled array joint transmit and receive beam, and thus improve the detection performance of the frequency-controlled array. Summary of the invention

[0004] The purpose of this application is to solve the problem of matching the receiving beam with the transmitting beam, obtain the time-varying receiving beam of the receiving array element of the frequency-controlled array by designing the time-varying receiving beam weight vector and the receiving beam optimization weight vector, obtain the directional pattern related to the distance angle of the frequency-controlled array, and enhance the control of the receiving beam directional pattern of the frequency-controlled array.

[0005] The technical solution of the present application is to provide a frequency-controlled array time-varying receiving beam forming method, the method comprising: step 1, within a preset main lobe space range, according to the frequency-controlled array transmitting beam P t (T, R, θ), calculate the time-varying receive beam weight vector w r (T); Step 2, time-varying receive beam weight vector WR (T) is discretized to determine the discrete weight vector w of the segmented time-varying receiving beam r (i); Step 3, according to the area coefficient of the desired beam coverage area, calculate the receiving beam optimization weight vector w corresponding to the maximum energy of the invariant beam when the frequency-controlled array receives within the area coefficient range q ; Step 4, based on the segmented time-varying receive beam discrete weight vector w r (i) Receive beam optimization weight vector w q and the receiving array steering vector a(R,θ), and calculate the time-varying directivity pattern of the frequency-controlled array time-varying receiving beam, wherein the time-varying directivity pattern is used to determine the frequency-controlled array time-varying receiving beam.

[0006] In any of the above technical solutions, further, step 1 specifically includes: step 101, determining a frequency-controlled array transmit beam P of a frequency-controlled array antenna T (T, R, θ) and frequency-controlled array receiving beam P r (T, R, θ); Step 102, calculate the frequency-controlled array transmit beam P within the preset main lobe space range t (T, R, θ) and the frequency-controlled array receiving beam P R Step 103: according to the absolute value of the first difference, the time-varying receiving elements in the frequency-controlled array receiving beam are calculated in sequence, and the time-varying receiving beam weight vector w is determined according to the time-varying receiving elements. r (T), where the time-varying receiving element is the element in the frequency-controlled array receiving beam that satisfies the first difference absolute value less than the preset threshold

[0007] In any of the above technical solutions, further, step 1 specifically includes: step 111, determining the frequency-controlled array transmit beam P of the frequency-controlled array antenna t (T, R, θ) and frequency-controlled array receiving beam P r (T, R, θ); Step 112, calculate the frequency-controlled array transmit beam P respectively t The even sum of (T, R, θ) and the frequency-controlled array receiving beam P t (T, R, θ); Step 113, calculate the second absolute value of the difference between the even summation term and all the summation terms; Step 114, sequentially calculate the time-varying receiving elements in the frequency-controlled array receiving beam when the absolute value of the second difference is 0, and determine the time-varying receiving beam weight vector w according to the time-varying receiving elements r (T).

[0008] In any of the above technical solutions, further, the frequency-controlled array transmits beam P t The expression of (T, R, θ) is:

[0009]

[0010] Where T is time, R is the observation distance, θ is the observation direction angle, m is the transmitting array element number, m = 0, 1, 2, ..., M, M is the number of transmitting array elements, is the transmit beam weight vector w t The mth element in is the frequency deflection of the frequency-controlled array, c is the speed of light, d t is the transmit array element spacing, f 0 is the reference frequency of the offset frequency array.

[0011] In any of the above technical solutions, further, the frequency-controlled array receiving beam P r The expression of (T, R, θ) is:

[0012]

[0013] In the formula, is the receive beam weight vector w r The nth element in (T), the receive beam weight vector is the receiving frequency deviation of the frequency-controlled array, n is the receiving array element number, n=0,1,2,…,N, N is the number of receiving array elements, d r is the receiving array element spacing.

[0014] In any of the above technical solutions, further, the preset main lobe spatial range is a rectangular range with the coherence point of the frequency-controlled array transmit beam as the set center, and the rectangular range is composed of an angle dimension edge and a distance dimension edge.

[0015] In any of the above technical solutions, further, step 2 specifically includes: according to the frequency-controlled array transmitting beam coherence distance R 1 and segment interval T p , determine the central time T i ; Based on the central time T i , for the time-varying receive beam weight vector w r (T) is discretized to determine the discrete weight vector w of the segmented time-varying receiving beam r (i).

[0016] In any of the above technical solutions, further, step 3 specifically includes:

[0017] Step 31, determining a desired beam distance range and a desired beam angle range, and calculating an area coefficient of the desired beam coverage area;

[0018] Step 32, calculating the observation airspace area coefficient of the observation airspace range;

[0019] Step 33, based on the area coefficient of the desired beam coverage area and the area coefficient of the observed airspace, calculate the receiving beam optimization weight vector w when the energy of the invariant beam pattern of the frequency-controlled array receiving time is the maximum within the area coefficient range. q , the corresponding calculation formula is:

[0020]

[0021] In the formula, w q is the receive beam optimization weight vector, a(R,θ) is the receive array steering vector of the receive element, θ is the observation direction angle, and R is the observation distance.

[0022] The beneficial effects of this application are:

[0023] The technical solution in the present application introduces a time-varying receiving beam weight vector into the frequency-controlled array antenna, and then obtains the corresponding segmented time-varying receiving beam discrete weight vector through discretization, and jointly calculates the time-varying radiation pattern of the frequency-varying receiving beam of the frequency-controlled array together with the receiving beam optimization weight vector and the receiving array steering vector to obtain the time-varying receiving beam of the receiving array element of the frequency-controlled array antenna, thereby solving the problem of matching the receiving beam with the transmitting beam and enhancing the control of the receiving beam radiation pattern of the frequency-controlled array.

[0024] Moreover, the frequency-controlled array time-varying receiving beamforming method in the present application can not only obtain the directional pattern related to the distance angle of the frequency-controlled array, but also retain the information related to the distance angle of the frequency-controlled array, and can realize beam convergence in a large range, thereby improving the overall performance of the frequency-controlled array antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The advantages of the above and / or additional aspects of the present application will become apparent and easily understood in the description of the embodiments in conjunction with the following drawings, in which:

[0026] Figure 1 is a schematic flow chart of a frequency-controlled array time-varying receive beamforming method according to an embodiment of the present application;

[0027] Figure 2 is a schematic diagram of the placement of the transmitting and receiving antennas according to an embodiment of the present application;

[0028] FIG3( a ) is a linear frequency deviation simulation diagram of a frequency-controlled array transmit beam according to an embodiment of the present application;

[0029] FIG3( b ) is a simulation diagram of the logarithmic frequency deviation of a frequency-controlled array transmit beam according to an embodiment of the present application;

[0030] FIG3( c ) is a simulation diagram of a sinusoidal frequency deviation of a frequency-controlled array transmit beam according to an embodiment of the present application;

[0031] FIG4( a ) is a frequency-controlled array time-varying receive beamforming pattern corresponding to a linear frequency offset according to an embodiment of the present application;

[0032] FIG4( b ) is a frequency-controlled array time-varying receive beamforming pattern corresponding to a logarithmic frequency offset according to an embodiment of the present application;

[0033] FIG4( c ) is a frequency-controlled array time-varying receive beamforming pattern corresponding to a sinusoidal frequency offset according to an embodiment of the present application;

[0034] FIG5( a ) is a frequency-controlled array time-varying joint transmit-receive beam pattern corresponding to a linear frequency offset according to an embodiment of the present application;

[0035] FIG5( b ) is a time-varying joint transmit-receive beam pattern of a frequency-controlled array corresponding to a logarithmic frequency offset according to an embodiment of the present application;

[0036] FIG5( c ) is a time-varying joint transmit-receive beam pattern of a frequency-controlled array corresponding to a sinusoidal frequency offset according to an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0038] In the following description, many specific details are elaborated to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited to the specific embodiments disclosed below.

[0039] Embodiment 1:

[0040] like Figure 1 As shown, this embodiment provides a frequency-controlled array time-varying receiving beamforming method, including:

[0041] Step 1: within the preset main lobe space, transmit beam P according to the frequency-controlled array t (T, R, θ), calculate the time-varying receive beam weight vector w r (T);

[0042] like Figure 2 As shown, the frequency-controlled array antenna includes transmitting array elements and receiving array elements. Taking the linear frequency-offset frequency-controlled array as an example, the number of transmitting array elements M is set to 12, and the reference frequency of the offset frequency-controlled array is f 0 =2GHz, frequency control array transmit frequency deviation coefficient Δf = 20kHz, transmit array element spacing d t =0.5λ 0 ,λ 0is the reference wavelength, λ 0 =c / f 0 =0.15m.

[0043] In this embodiment, the frequency-controlled array transmit beam coherence point (θ, R 1 ) is (30°, 50km), where Θ is the coherent direction angle of the frequency-controlled array transmission beam, R 1 is the coherence distance of the frequency-controlled array transmitting beam.

[0044] Specifically, as shown in FIG3 , for any frequency-controlled array transmit beam, the frequency-controlled array transmit beam P t (T, R, θ) is expressed by the first expression:

[0045]

[0046] In the formula, is the frequency deviation of the frequency-controlled array, m is the number of the transmitting array element, m=0,1,2,…,M, M is the number of transmitting array elements, f 0 is the reference frequency of the offset frequency array, c is the speed of light, θ is the observation direction angle, R is the observation distance, T is the time, d t is the transmit array element spacing, is the transmit beam weight vector w t The mth element in

[0047] The superscript t in the above formula represents the transmitting array element.

[0048] It should be noted that in this embodiment, the number of transmit array elements M can be an even number, such as M = 8. When the number of transmit array elements is 8, the specific implementation process is similar to that when the number of transmit array elements is 12, and will not be repeated.

[0049] According to Figure 2 The configuration of the transmit and receive antennas shown in the figure can control the frequency array receiving beam P r (T, R, θ) is expressed by the second expression:

[0050]

[0051] In the formula, is the receiving frequency deviation of the frequency-controlled array, n is the receiving array element number, n=0,1,2,…,N, N=M / 2, N is the number of receiving array elements, is the receive beam weight vector w r The nth element in (T), the receive beam weight vector d r is the receiving array element spacing.

[0052] The superscript r in the above formula represents the receiving array element.

[0053] In this embodiment, the preset main lobe space range is defined as follows:

[0054] As shown in FIG3 , the preset main lobe spatial range is based on the frequency-controlled array transmit beam coherence point (θ, R 1 )=(30°, 50km) as the center, which is represented by a dotted box in Figure 3. The rectangular range consists of an angle dimension and a distance dimension, wherein the angle dimension of the rectangle is 0°~60°, and the side length is 60°, and the distance dimension of the rectangle is 40km~60km, and the side length is 20km.

[0055] Therefore, by analyzing the directional pattern, in order to enable the receiving array element to obtain a time-varying receiving beam, a time-varying receiving beam weight vector w is introduced into the receiving array element. r (T), the time-varying receive beam weight vector w r The calculation methods of (T) include:

[0056] Step 102, calculating a first absolute value of a difference between a frequency-controlled array transmit beam and a frequency-controlled array receive beam of the frequency-controlled array antenna within a preset main lobe space range;

[0057] Step 103: according to the absolute value of the first difference, the time-varying receiving elements in the frequency-controlled array receiving beam are calculated in sequence, and the time-varying receiving beam weight vector w is determined according to the calculated time-varying receiving elements. r (T), where the time-varying receiving element is the element in the frequency-controlled array receiving beam that satisfies the first difference absolute value less than the preset threshold

[0058] Step 2: Time-varying receive beam weight vector w r (T) is discretized to determine the discrete weight vector w of the segmented time-varying receiving beam r (i) The process specifically includes:

[0059] According to the frequency-controlled array transmitting beam coherence distance R 1 and segment interval T p , determine the central time T i ;

[0060] Based on the central time T i , for the time-varying receive beam weight vector w r (T) is discretized to determine the discrete weight vector w of the segmented time-varying receiving beam r (i).

[0061] Specifically, set the segment interval to T p , according to the coherence distance R of the frequency-controlled array transmitting beam 1 , calculate the central moment of any segment, the corresponding calculation formula is:

[0062]

[0063] Where, T i is the central moment, c is the speed of light, i is the time segment number, i=1,2,…,I, I is the time segment number.

[0064] Therefore, the discrete weight vector w of the piecewise time-varying receiving beam is r The calculation formula for (i) is:

[0065]

[0066] In the formula, w r (T=T i ) is the time-varying receiving beam weight vector at the center moment. At this time, the center moment That is, the discrete moment corresponding to the range-dimensional translation trajectory of the main lobe of the transmitting beam.

[0067] Set the frequency-controlled array transmit beam coherence distance R 1 =50km, segment interval T p = 1 μs, the number of time segments I = 10, n is the receiving array element number, n = 0, 1, 2, ..., N-1, N is the number of receiving array elements, and the value is 6. Therefore, for the receiving array element, the discrete weight vector w of the segmented time-varying receiving beam corresponding to the center time of the first four segments is r (i) As shown in Table 1.

[0068] Table 1

[0069]

[0070] Step 3: According to the area coefficient of the desired beam coverage area, calculate the corresponding receiving beam optimization weight vector w when the invariant beam energy of the frequency-controlled array is the maximum within the area coefficient range. q .

[0071] The process specifically includes:

[0072] Step 31, determine the expected beam distance range and the expected beam angle range, and calculate the area coefficient of the expected beam coverage area.

[0073] Specifically, the desired beam coverage area is set to a rectangle, with the desired beam distance range and the desired beam angle range on both sides, where the desired beam distance range is R 1 to R 2 , the desired beam angle range is θ 1 to θ 2 , the expected beam distance range can be set to 49-51km, and the expected beam angle range can be set to -5°~5°.

[0074] According to the invariant beam pattern of the frequency-controlled array receiving time, the 3dB width γ of the frequency-controlled array beam distance and the 3dB width Θ of the frequency-controlled array beam angle, the corresponding values ​​are shown in Table 2.

[0075] Table 2

[0076] M＝12 γ Θ Linear frequency deviation 1.1km 10.2° Logarithmic frequency deviation 4.4km 10.2° Sine frequency deviation 4.5km 10.2°

[0077] Based on the above parameters, the area coefficient S of the desired beam coverage area is calculated. The corresponding calculation formula is:

[0078]

[0079] Step 32, calculate the observation airspace area coefficient of the observation airspace range, and the corresponding calculation formula is:

[0080]

[0081] Where Ω is the observation space area coefficient, R max is the maximum distance of the desired beam airspace range, which can be set to 60km, R min is the minimum distance of the desired beam airspace range, which can be set to 40km, θ max is the maximum angle of the desired beam spatial domain, and its value is set to π / 2, θ min is the maximum angle of the desired beam spatial range, and its value is set to -π / 2.

[0082] It should be noted that the distance range of the observation airspace satisfies the following relationship:

[0083] |R max -R min |>10|R 2 -R 1 |

[0084] In this embodiment, since the frequency-controlled array beam is a range-angle related beam, and the distance parameter and the angle parameter can be proved to be independent, the distance range and the angle range area are selected as parameters for beam forming, that is, the area coefficient S of the desired beam coverage area. At the same time, the frequency-controlled array beam distance 3dB width γ and the frequency-controlled array beam angle 3dB width Θ are introduced, and the area coefficient S of the desired beam coverage area and the observation space area coefficient are normalized. The receiving beam optimization weight vector w when the receiving pattern energy is maximum is used. q , achieving the beneficial effect of maximum reception of beam energy.

[0085] The calculation results of the area coefficient S of the expected beam coverage area and the observation space area coefficient Ω are shown in Table 3.

[0086] Table 3

[0087] M＝12 S Ω Linear frequency deviation 0.8562 154.1096 Logarithmic frequency deviation 0.2362 42.5130 Sine frequency deviation 0.2446 44.0313

[0088] Step 33, according to the area coefficient of the expected beam coverage area and the area coefficient of the observed airspace, calculate the receiving beam optimization weight vector when the energy of the invariant beam pattern of the frequency-controlled array receiving time is maximum within the area coefficient range, and the corresponding calculation formula is:

[0089]

[0090] In the formula, w q is the receive beam optimization weight vector, a(R,θ) is the receive array steering vector of the receive element, θ is the observation direction angle, and R is the observation distance.

[0091] Specifically, based on the above parameters, the calculated receive beam optimization weight vector is shown in Table 4.

[0092] Table 4

[0093] n <![CDATA[w q ]]> 0 -0.3536+0.0000j 1 -0.3019-0.1841j 2 -0.1619-0.3143j 3 0.0255-0.3526j 4 -0.6812-0.0971j 5 0.6587+0.0098j

[0094] Step 4: Discrete weight vector w according to the segmented time-varying receiving beam r (i) Receive beam optimization weight vector w q And the receiving array steering vector a(R,θ), calculate the time-varying directivity pattern of the frequency-controlled array time-varying receiving beam, where the time-varying directivity pattern is used to determine the time-varying receiving beam of the frequency-controlled array, and the calculation formula corresponding to the time-varying directivity pattern is:

[0095] P(r,θ,i)=w r (i) H w q H a(R,θ)

[0096] In the formula, w r (i) H w r The conjugate transposed matrix of (i).

[0097] Embodiment 2:

[0098] Based on the above embodiment, since the absolute value of the difference is compared with the preset threshold, although the corresponding time-varying receiving beam weight vector w can be calculated r (T), when the amount of calculation is relatively large, and the calculation result is not intuitive enough in the numerical calculation process, it is not convenient for numerical analysis. Therefore, this embodiment also shows a method for calculating the time-varying receiving beam weight vector w r (t) method, select the frequency-controlled array transmit beam P t The even sum of (T, R, θ) is used to calculate the time-varying receive beam weight vector w r(T) is calculated to obtain an accurate analytical solution, the method specifically includes:

[0099] Step 111, determine the frequency-controlled array transmit beam P of the frequency-controlled array antenna t (T, R, θ) and frequency-controlled array receiving beam P r (T, R, θ);

[0100] Step 112, respectively calculate the frequency-controlled array transmit beam P t The even summation term U(T,R,θ) of (T,R,θ) and the frequency-controlled array receiving beam P r The corresponding calculation formulas for all the summation terms (T, R, θ) of (t, r, θ) are as follows:

[0101]

[0102]

[0103] Step 113, calculating the second absolute value of the difference between the even summation term U(T, R, θ) and all the summation terms (T, R, θ);

[0104] Step 114, sequentially calculate the time-varying receiving elements in the frequency-controlled array receiving beam when the absolute value of the second difference is 0, and determine the time-varying receiving beam weight vector w according to the time-varying receiving elements r (T), where the time-varying receive beam weight vector w r The formula for calculating the rth element in (t) is:

[0105]

[0106] By analyzing the frequency-steering array time-varying receiving beamforming method in the above embodiment, and comparing Figures 3 and 4, under the same frequency setting, taking the logarithmic frequency offset frequency-steering array transmitting beam in Figure 3 (b) and the logarithmic frequency offset frequency-steering array time-varying receiving beam in Figure 4 (b) as examples, within the main lobe space, the absolute error between the directivity pattern of the logarithmic frequency offset frequency-steering array transmitting beam and the directivity pattern of the logarithmic frequency offset frequency-steering array time-varying receiving beam is less than 25%, and it is considered that the logarithmic frequency offset frequency-steering array transmitting beam and the logarithmic frequency offset frequency-steering array time-varying receiving beam are similar within the main lobe space.

[0107] It should be noted that other frequency offsets (such as linear frequency offset and sinusoidal frequency offset) can also obtain the same result.

[0108] In this embodiment, the time-varying receiving weight vector designed according to the time-varying law of the frequency-controlled array transmitting beam can achieve the matching of the frequency-controlled array receiving beam and the frequency-controlled array transmitting beam.

[0109] As shown in Figure 5, compared with the joint transmit-receive beam pattern formed by the existing time-invariant receiving weight vector, the time-varying joint transmit-receive beam pattern of the frequency-controlled array in this embodiment can form a distance and angle coverage area of ​​the frequency-controlled array joint transmit-receive beam, and form a distance-angle related coverage range within the main lobe airspace, where the distance range exceeds 5km and the angle range exceeds 10°.

[0110] The above describes in detail the technical solution of the present application in conjunction with the accompanying drawings. The present application proposes a method for forming a time-varying receiving beam of a frequency-controlled array, the method comprising: step 1, calculating the time-varying receiving beam weight vector according to the frequency-controlled array transmitting beam within the preset main lobe space range; step 2, discretizing the time-varying receiving beam weight vector to determine the segmented time-varying receiving beam discrete weight vector; step 3, calculating the receiving beam optimization weight vector corresponding to the maximum receiving time-varying beam energy of the frequency-controlled array within the area coefficient range according to the area coefficient of the expected beam coverage area; step 4, calculating the time-varying radiation pattern of the time-varying receiving beam of the frequency-controlled array according to the segmented time-varying receiving beam discrete weight vector, the receiving beam optimization weight vector and the receiving array steering vector. The technical solution in the present application solves the problem of matching the receiving beam with the transmitting beam, and by designing the time-varying receiving beam weight vector and the receiving beam optimization weight vector, the time-varying receiving beam of the receiving element of the frequency-controlled array is obtained, thereby enhancing the control of the receiving beam radiation pattern of the frequency-controlled array.

[0111] The steps in this application can be adjusted in order, combined, and deleted according to actual needs.

[0112] The units in the device of the present application can be combined, divided and deleted according to actual needs.

[0113] Although the present application is disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and are not intended to limit the application of the present application. The scope of protection of the present application is defined by the appended claims and may include various modifications, alterations and equivalents made to the invention without departing from the scope and spirit of the present application.

Claims

1. A frequency-controlled array time-varying receiving beamforming method, It is characterized in that The method includes: Step 1: within the preset main lobe space, transmit beam P according to the frequency-controlled array t (T, R, θ), calculate the time-varying receive beam weight vector w r (T); Step 2: The time-varying receive beam weight vector w r (T) is discretized to determine the discrete weight vector w of the segmented time-varying receiving beam r (i); Step 3: Calculate the receiving beam optimization weight vector w corresponding to the maximum receiving time-invariant beam energy of the frequency-controlled array within the area coefficient range according to the area coefficient of the desired beam coverage area. q ; Step 4: discrete weight vector w of the segmented time-varying receiving beam r (i) The receive beam optimization weight vector w q and a receiving array steering vector a(R,θ), and calculating a time-varying directivity pattern of a frequency-controlled array time-varying receiving beam, wherein the time-varying directivity pattern is used to determine the frequency-controlled array time-varying receiving beam.

2. The frequency-controlled array time-varying receiving beamforming method according to claim 1, It is characterized in that The step 1 specifically includes: Step 101: determine the frequency-controlled array transmit beam P of the frequency-controlled array antenna t (T, R, θ) and frequency-controlled array receiving beam P r (T, R, θ); Step 102: Calculate the frequency-controlled array transmit beam P within the preset main lobe space. t (T, R, θ) and the frequency-controlled array receiving beam P r The absolute value of the first difference of (T, R, θ); Step 103: according to the absolute value of the first difference, the time-varying receiving elements in the frequency-controlled array receiving beam are calculated in sequence, and the time-varying receiving beam weight vector w is determined according to the time-varying receiving elements. r (T), The time-varying receiving element is an element in the frequency-controlled array receiving beam that satisfies the first difference absolute value less than a preset threshold.

3. The frequency-controlled array time-varying receiving beamforming method according to claim 1, It is characterized in that The step 1 specifically includes: Step 111, determine the frequency-controlled array transmit beam P of the frequency-controlled array antenna t (T, R, θ) and frequency-controlled array receiving beam P r (T, R, θ); Step 112, respectively calculate the frequency-controlled array transmit beam P t The even sum of (T, R, θ) and the frequency-controlled array receiving beam P r All sums of (T, R, θ); Step 113, calculating the second absolute value of the difference between the even summation term and all the summation terms; Step 114, sequentially calculating the time-varying receiving elements in the frequency-controlled array receiving beam when the absolute value of the second difference is 0, and determining the time-varying receiving beam weight vector w according to the time-varying receiving elements r (T).

4. The frequency-controlled array time-varying receiving beamforming method according to claim 2 or 3, It is characterized in that The frequency-controlled array transmits beam P t The expression of (T, R, θ) is: Where T is time, R is the observation distance, θ is the observation direction angle, m is the transmitting array element number, m = 0, 1, 2, ..., M, M is the number of transmitting array elements, is the transmit beam weight vector w t The mth element in is the frequency deflection of the frequency-controlled array, c is the speed of light, d t is the transmit array element spacing, f 0 is the reference frequency of the offset frequency array.

5. The frequency-controlled array time-varying receiving beamforming method according to claim 2 or 3, It is characterized in that The frequency controlled array receives beam P r The expression of (T, R, θ) is: In the formula, is the receive beam weight vector w r The nth element in (T), the receive beam weight vector is the frequency deviation of the frequency-controlled array receiving frequency, n is the receiving array element number, n = 0, 1, 2, ..., N, N is the number of receiving array elements, d r is the receiving array element spacing.

6. The frequency-controlled array time-varying receiving beamforming method according to any one of claims 1 to 3, It is characterized in that The preset main lobe space range is a rectangular range with the frequency-controlled array transmit beam coherence point as the set center, and the rectangular range is composed of an angle dimension side and a distance dimension side.

7. The frequency-controlled array time-varying receiving beamforming method according to claim 1, It is characterized in that The step 2 specifically includes: According to the frequency-controlled array transmitting beam coherence distance R 1 and segment interval T p , determine the central time T i ; Based on the central time T i , for the time-varying receive beam weight vector w r (T) discretizes to determine the discrete weight vector w of the segmented time-varying receiving beam r (i).

8. The frequency-controlled array time-varying receiving beamforming method according to claim 1, It is characterized in that The step 3 specifically includes: Step 31, determining a desired beam distance range and a desired beam angle range, and calculating an area coefficient of the desired beam coverage area; Step 32, calculating the observation airspace area coefficient of the observation airspace range; Step 33, according to the area coefficient of the desired beam coverage area and the observed spatial area coefficient, calculate the receiving beam optimization weight vector w when the energy of the invariant beam pattern of the frequency-controlled array receiving time is the maximum within the area coefficient range. q , the corresponding calculation formula is: w q ： In the formula, w q is the receive beam optimization weight vector, a(R, θ) is the receive array steering vector of the receive array element, θ is the observation direction angle, and R is the observation distance.

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