Design method of active coupling radar uniform area array

Abstract

The invention discloses an active coupling radar uniform area array design method, and belongs to the technical field of radar arrays, and the method comprises the following steps: S1, obtaining a double-array-element active coupling input signal, constructing an active coupling model, and generating an active coupling double-array-element radar array; s2, performing block processing according to the active coupling double-array-element radar array to obtain an active coupling uniform linear array; and S3, determining an active coupling radar uniform area array according to the active coupling uniform linear array. The method has good engineering practicability and compatibility, model parameters can be flexibly adjusted according to actual requirements based on standardized matrix operation and partitioning processing, radar systems with different frequency bands and resolution requirements are adapted, meanwhile, engineering manufacturing and integration are facilitated through modular design of the area array structure, and the deployment cost of a large-scale array is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of radar array, and particularly relates to a design method of an active coupling radar uniform surface array. BACKGROUND

[0002] The biological world has undergone a long evolution, and many ingenious methods have emerged to adapt to nature, which provides infinite inspiration for science and technology. The hearing structure of Ormiaomia has attracted extensive research due to its outstanding sound localization ability. Today, due to the continuous improvement of sensor performance and the continuous improvement of computer capability and efficiency, the application of sound source localization technology is becoming more and more widespread. In the field of electromagnetic wave detection, the same as the sound array, the incident direction of the echo signal needs to be determined by detecting the phase difference of the output signals of each array element, so this sensing method will also help to solve the miniaturization problem of the antenna array.

[0003] After the excellent sound localization ability of Ormiaomia was discovered, based on the mechanism of improving the direction perception ability of the positioning device to the sound source through structural coupling, foreign scholars have carried out a number of design and research work on micro-bionic sound sensing structures. In the existing research results, the coupling structure of the hearing system of Ormiaomia is directly borrowed to realize the coupling amplification mechanism, but no effective direction angle estimation method is proposed, and the sensing of the sound source direction angle is limited to two-dimensional plane, and the coupling amplification mechanism is not extended to three-dimensional space.

[0004] The traditional bionic radar array is limited to the use of a double-array structure, and its design inspiration comes from the single pair of ear mechanism of Ormiaomia, which leads most bionic radar array research to focus on the development of double-array. However, two-dimensional surface array structure has higher information acquisition capability and wider field of view, which can theoretically further improve the imaging quality and target recognition capability. The surface array needs to process the signal coupling problem in the horizontal and vertical dimensions at the same time, and the coupling mechanism of the traditional double-array and linear array cannot be directly applied. Specifically, the complexity of the coupling path between two-dimensional array elements and the dimension jump of parameter design lead to double challenges in the theoretical modeling and practical application of bionic surface array, which seriously limits its potential in three-dimensional space perception. SUMMARY

[0005] The application is proposed to solve the above problems, and provides a design method of an active coupling radar uniform surface array.

[0006] The technical scheme of the application is as follows: a design method of an active coupling radar uniform surface array comprises the following steps: S1, acquiring an input signal of a double-array active coupling, constructing an active coupling model, and generating an active coupling double-array radar array; S2, performing block processing according to the active coupling double-array radar array to obtain an active coupling uniform linear array. S3, determining the active coupling radar uniform planar array according to the active coupling uniform linear array.

[0007] Further, S1 comprises the following sub-steps: S11, acquiring the input signal of the double-element active coupling; S12, determining the output signal of the double-element active coupling; S13, constructing an active coupling model according to the input signal and the output signal of the double-element active coupling, and generating the active coupling double-element radar array.

[0008] Further, in S11, the first input signal x1 of the double-element active coupling is expressed as: ; In the formula, x1 represents one input on the adjacent two elements of the array incident signal, x2 represents the other input on the adjacent two elements of the array incident signal, A0 represents the signal amplitude, a represents the phase, and j represents the imaginary number; In S11, the second input signal x2 of the double-element active coupling is expressed as: .

[0009] Further, in S12, the first output signal y1 of the double-element active coupling is expressed as: ; In the formula, G represents the gain of the forward channel, H represents the gain of the coupling channel, z1 represents the first signal input to the active coupling part, z2 represents the second signal input to the active coupling part, A0 represents the signal amplitude, and a represents the phase; In S12, the second output signal y2 of the double-element active coupling is expressed as: .

[0010] Further, in S13, the expression of the active coupling model is: ; ; ; In the formula, Z represents the active coupling gain matrix, D represents the coefficient matrix, G represents the gain of the forward channel, H represents the gain of the coupling channel, x1 represents one input on the adjacent two elements of the array incident signal, x2 represents the other input on the adjacent two elements of the array incident signal, represents the forward channel noise of the first element, represents the forward channel noise of the second element,​​ represents the coupling channel noise of the first array element, represents the coupling channel noise of the second array element, y1 represents the first output signal of the dual-array active coupling, and y2 represents the second output signal of the dual-array active coupling.

[0011] Further, in S13, the expression of the first output loss L1(α) of the active coupling model is: ; In the formula, x1 represents one input on the adjacent two array elements of the array incident signal, y1 represents the first output signal of the dual-array active coupling, G represents the gain of the forward channel, H represents the gain of the coupling channel, α represents the phase, and lg(·) represents the logarithmic function. In S13, the expression of the second output loss L2(α) of the active coupling model is: ; In the formula, x2 represents the other input on the adjacent two array elements of the array incident signal, and y2 represents the second output signal of the dual-array active coupling.

[0012] Further, in S2, the expression of the model Y of the active coupling uniform linear array is: ; ; ; ; In the formula, represents the active coupling matrix of the uniform linear array, represents the coefficient matrix of the uniform linear array, X represents the original array received signal, N A represents the antenna noise, N H represents the thermal noise, blkdiag{·} represents the inverse diagonal operator, Z represents the active coupling gain matrix, D represents the coefficient matrix, x1 represents the first input on the adjacent two array elements of the array incident signal, x 2M represents the second M input on the adjacent two array elements of the array incident signal.

[0013] Further, S3 includes the following sub-steps: S31, based on the active coupling uniform linear array, an active coupling uniform planar array is constructed; S32, the active coupling uniform planar array is split into x and y directions, the decoupling design is completed, and the final active coupling radar uniform planar array is generated.

[0014] Further, in S31, the expression of the original data model W of the active coupling uniform planar array is: ; ; ; wherein A x represents a steering vector matrix in the x direction, A y represents a steering vector matrix in the y direction, denotes Khatri-Rao product, S represents a signal matrix, N A represents an antenna noise matrix, N H represents a thermal noise matrix, s1 represents a first signal, s2 represents a second signal, s K represents a Kth target, represents a steering vector of a first target in the x direction, represents a steering vector of a Kth target in the x direction, represents a steering vector of a first target in the y direction, represents a steering vector of a Kth target in the y direction.

[0015] Further, in S32, the expression for decoupling design is: ; ; ; wherein W represents an original data model of an active coupling uniform planar array, U x represents a coupling matrix in the x direction, U y represents a coupling matrix in the y direction, represents an active coupling matrix of a uniform linear array, represents a coefficient matrix of a uniform linear array, S represents a signal matrix, represents a steering vector of an ith target in the x direction, represents a steering vector of an ith target in the y direction, denotes Kronecker product, N A represents an antenna noise, N H represents a thermal noise, and K represents a target quantity.

[0016] The present application has the following beneficial effects: (1) The application solves the problem of output power loss, improves signal utilization efficiency, and the existing bionic coupling structure has a mismatch in transfer function order, and the output power loss can reach-30dB, which seriously restricts the sensitivity of the radar, the application designs an active coupling model (introduces forward channel gain and coupling channel gain), when G=0dB, the output can be realized without attenuation, and through parameter optimization, the maximum output gain is improved to 43.94dB, which significantly improves the utilization rate of signal power, and solves the problem of unadjustable power loss caused by mechanical parameter limitation in traditional structure.

[0017] (2) The application simplifies two-dimensional coupling design and realizes modular expansion. The coupling path of the traditional two-dimensional array is complex, the parameter design dimension is high, and it is difficult to reuse the linear array theory. The application splits the surface array into independent coupling design in x and y directions, converts the two-dimensional problem into the coupling problem of two one-dimensional linear arrays by using the decoupling model, so that the coupling theory of the active uniform linear array can be directly transplanted to the surface array, the design complexity is reduced, and the modular expansion from double elements to linear array to surface array is realized.

[0018] (3) The application improves the angle resolution and three-dimensional perception ability. The phase difference between the elements is amplified through the active coupling mechanism, and the spatial layout of the uniform surface array is combined to realize the-3dB target spatial angle resolution, which significantly improves the angle resolution ability of the traditional array. At the same time, through the x-y direction decoupling design, the limitation of the traditional bionic array to two-dimensional plane perception is broken, the three-dimensional space target positioning of azimuth and elevation angle is supported, and the application scene of the radar is expanded.

[0019] (4) The application enhances the noise suppression ability and optimizes the signal quality. The quantitative analysis of antenna noise and thermal noise is introduced in the model, the influence of noise on the output signal is reduced through the design of coupling matrix and coefficient matrix, compared with the traditional structure which can only passively bear noise interference, the active coupling model of the application can suppress noise amplification through gain parameter adjustment, and the signal-to-noise ratio of the output signal is improved.

[0020] (5) The application has good engineering practicability and compatibility. Based on the standardized matrix operation and block processing, the model parameters can be flexibly adjusted according to actual requirements, and the radar system with different frequency bands and resolution requirements can be adapted. At the same time, the modular design of the surface array structure is convenient for engineering manufacturing and integration, and reduces the deployment cost of large-scale array. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a flow chart of the design method of the active coupling radar uniform surface array; Figure 2 It is a double-element active coupling structure diagram; Figure 3 It is a schematic diagram of a uniform surface array; Figure 4 Output loss diagram for active coupling uniform planar array; Figure 5 Phase difference diagram for active coupling uniform planar array; Figure 6 3dB target resolution diagram for active coupling uniform planar array. DETAILED DESCRIPTION

[0022] The embodiments of the present application will be further described below with reference to the drawings.

[0023] As Figure 1 shown, the present application provides an active coupling radar uniform planar array design method, comprising the following steps: S1, obtaining the input signal of double-element active coupling, constructing an active coupling model, and generating an active coupling double-element radar array; S2, according to the active coupling double-element radar array, performing block processing to obtain an active coupling uniform linear array; S3, according to the active coupling uniform linear array, determining an active coupling radar uniform planar array.

[0024] The present application decouples the complex two-dimensional active coupling design into independent coupling design in x and y directions by using original coupling reverse splitting in x and y directions, so that the theory of active uniform linear array coupling can be transplanted to the case of uniform planar array.

[0025] The core of the biomimetic radar array is the mechanical biomimicry of the auditory system of Ormia Oleracea, although the biomimetic coupling improves the angle resolution by expanding the phase difference between the outputs, the loss of output power is very serious, even up to-30dB, because the order of the denominator of the transfer function is 4, and the order of the molecule is 2, with the increase of frequency, the rate of the molecule becomes larger than the denominator, and the loss of output power becomes inevitable. Due to the structural limitations, optimization of stiffness and damping parameters cannot well solve the problem of output power loss.

[0026] Consider the theoretical model of double-element active coupling as Figure 2 shown, wherein G and H are the gains of the forward path and the coupling path of the active coupling part respectively, and are the external antenna noise and the internal equivalent thermal noise respectively, x1 and x2 are the inputs on the adjacent two elements of the array incident signal, y1 and y2 are the outputs of the two-way active coupling respectively.

[0027] In the embodiments of the present application, S1 comprises the following sub-steps: S11, obtaining the input signal of double-element active coupling; S12, determining the output signal of double-element active coupling; S13, constructing an active coupling model according to the input signal and the output signal of the double-element active coupling, and generating the active coupling double-element radar array.

[0028] In the embodiment of the present application, in S11, the expression of the first input signal of the double-element active coupling is: In the expression, x1 represents one input on the adjacent two elements of the array incident signal, x2 represents the other input on the adjacent two elements of the array incident signal, A0 represents the signal amplitude, a represents the phase, and j represents the imaginary number. In S11, the expression of the second input signal of the double-element active coupling is:

[0029] In the embodiment of the present application, in S12, the expression of the first output signal y1 of the double-element active coupling is: In the expression, G represents the gain of the forward channel, H represents the gain of the coupling channel, z1 represents the first signal input to the active coupling part, z2 represents the second signal input to the active coupling part, A0 represents the signal amplitude, and a represents the phase. In S12, the expression of the second output signal y2 of the double-element active coupling is:

[0030] The two design parameters G and H can be determined by performance indicators. First, the size of the gain G is determined by the output power loss, and when the element spacing is one-quarter wavelength, the amplitude of the active coupling output can be represented as: The corresponding output loss is: When the output is required to be undamped, and H>G>0 and a=0, the minimum value of the active coupling output loss is: Therefore, there is a very intuitive result: the maximum loss of the active coupling output is G dB, and when G=0 dB, the output can be achieved without attenuation. When G is determined, H can be directly determined according to the performance indicator requirement of the phase difference amplitude, and the phase difference of the active coupling output can be represented as:​​​​​​​​​​​​ ; Considering the case of noisy input, the active coupling model can be expressed in the form of a matrix.

[0031] In the embodiment of the present application, in S13, the expression of the active coupling model is: ; ; ; In the formula, Z represents the active coupling gain matrix, D represents the coefficient matrix, G represents the gain of the forward channel, H represents the gain of the coupling channel, x1 represents one input on the adjacent two elements of the array incident signal, x2 represents the other input on the adjacent two elements of the array incident signal, represents the forward channel noise of the first element, represents the forward channel noise of the second element, represents the coupling channel noise of the first element, represents the coupling channel noise of the second element, y1 represents the first output signal of the dual-element active coupling, and y2 represents the second output signal of the dual-element active coupling.

[0032] In the embodiment of the present application, in S13, the expression of the first output loss L1(α) of the active coupling model is: ; In the formula, x1 represents one input on the adjacent two elements of the array incident signal, y1 represents the first output signal of the dual-element active coupling, G represents the gain of the forward channel, H represents the gain of the coupling channel, α represents the phase, and lg(·) represents the logarithmic function; In S13, the expression of the second output loss L2(α) of the active coupling model is: ; In the formula, x2 represents the other input on the adjacent two elements of the array incident signal, and y2 represents the second output signal of the dual-element active coupling.

[0033] The noise output of the active coupling can be expressed as: ; ; The corresponding noise output power is: ; ; In the formula, represents the antenna noise power, denotes the equivalent thermal noise power, denotes a complex Gaussian distribution.

[0034] In the embodiment of the present application, in S2, the expression of the model Y of the active coupling uniform linear array is: ; ; ; ; In the formula, denotes the active coupling matrix of the uniform linear array, denotes the coefficient matrix of the uniform linear array, X denotes the original array receiving signal, N A denotes the antenna noise, N H denotes the thermal noise, blkdiag{·} denotes the anti-diagonal operator, Z denotes the active coupling gain matrix, D denotes the coefficient matrix, x1 denotes the 1st input on the adjacent two elements of the array incident signal, x 2M denotes the 2Mth input on the adjacent two elements of the array incident signal.

[0035] , M is half of the number of elements. denotes the forward channel noise of the 2Mth element, denotes the coupling channel noise of the 2Mth element.

[0036] In the embodiment of the present application, S3 includes the following sub-steps: S31, based on the active coupling uniform linear array, an active coupling uniform planar array is constructed; S32, the active coupling uniform planar array is split into x direction and y direction, the decoupling design is completed, and the final active coupling radar uniform planar array is generated.

[0037] In the embodiment of the present application, in S31, the expression of the original data model W of the active coupling uniform planar array is: ; ; ; In the formula, A x denotes the steering vector matrix in the x direction, A y denotes the steering vector matrix in the y direction, represents the Khatri-Rao product, S denotes the signal matrix, N A denotes the antenna noise matrix, N Hrepresents thermal noise matrix, s1 represents the first signal, s2 represents the second signal, s K represents the Kth target, represents the guiding vector of the first target in the x direction, represents the guiding vector of the Kth target in the x direction, represents the guiding vector of the first target in the y direction, represents the guiding vector of the Kth target in the y direction. represents the guiding vector of the ith target in the x direction, , represents the guiding vector of the ith target in the y direction, , d x represents the element spacing in the x direction, d y represents the element spacing in the y direction, j represents imaginary number, T represents transposition, theta i represents the azimuth angle of the ith target, phi i represents the elevation angle of the ith target.

[0038] In the embodiment of the application, in S32, the expression for decoupling design is: ; ; ; In the formula, W represents the original data model of the active coupling uniform planar array, U x represents the coupling matrix in the x direction, U y represents the coupling matrix in the y direction, represents the active coupling matrix of the uniform linear array, represents the coefficient matrix of the uniform linear array, S represents the signal matrix, represents the guiding vector of the ith target in the x direction, represents the guiding vector of the ith target in the y direction, represents the Kronecker product, N A represents the antenna noise, N H represents the thermal noise, and K represents the number of targets.

[0039] In the embodiment of the application, the uniform planar array is as shown in Figure 3 The active coupling uniform planar array design can be split into x and y directions, and the result of the uniform linear array can be directly applied to each dimension of the uniform planar array. Figure 4 The element output has no loss, but due to the fact that the elements in the middle region are surrounded in two directions, the highest output gain can reach dB10lg((10 H / 10 ) 4 )=43.9428dB.

[0040] like Figure 5 As shown in , the phase difference in both directions is effectively amplified. Figure 6 As shown in the figure, it is proved that the actively coupled uniform array can effectively achieve -3dB target spatial angle resolution in two directional dimensions, which also provides a model basis for the subsequent realization of robust parameter estimation.

[0041] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A method for designing a uniform array of an active coupled radar, characterized in that: The following steps are involved: S1. Obtain the input signal of the dual-element active coupling, build an active coupling model, and generate an active coupling dual-element radar array; S2. Perform block processing on the active coupled dual-element radar array to obtain an active coupled uniform linear array; S3. Determine a final active coupled radar uniform array based on the active coupled uniform linear array.

2. The active coupled radar uniform array design method according to claim 1, characterized in that: The S1 includes the following sub-steps: S11, obtaining an input signal of dual-element active coupling; S12, determining the output signal of the dual-element active coupling; S13. Construct an active coupling model based on the input signal and output signal of the dual-element active coupling to generate an active coupling dual-element radar array.

3. The method for designing a uniform array of an active coupled radar according to claim 2, wherein: In S11, the first input signal of the dual array element active coupling The expression is: ； Where x1 represents one input of the array incident signal on two adjacent array elements, x2 represents the other input of the array incident signal on two adjacent array elements, A0 represents the signal amplitude, α represents the phase, and j represents the imaginary number; In S11, the second input signal of the dual array element active coupling The expression is: 。 4. The method for designing a uniform array of an active coupled radar according to claim 2, wherein: In S12, the expression of the first output signal y1 of the dual-element active coupling is: ； Where G represents the gain of the forward path, H represents the gain of the coupling path, z1 represents the first signal input to the active coupling part, z2 represents the second signal input to the active coupling part, A0 represents the signal amplitude, and α represents the phase; In S12, the expression of the second output signal y2 of the dual-element active coupling is: 。 5. The method for designing a uniform array of an active coupled radar according to claim 2, wherein: In S13, the expression of the active coupling model is: ； ； ； Where Z represents the active coupling gain matrix, D represents the coefficient matrix, G represents the gain of the forward channel, H represents the gain of the coupling channel, x1 represents an input of the array incident signal on two adjacent array elements, and x2 represents the other input of the array incident signal on two adjacent array elements. represents the forward channel noise of the first array element, represents the forward channel noise of the second array element, represents the coupled channel noise of the first array element, represents the coupling channel noise of the second array element, y1 represents the first output signal of the dual-element active coupling, and y2 represents the second output signal of the dual-element active coupling.

6. The method for designing a uniform array of an active coupled radar according to claim 2, wherein: In S13, the expression of the first output loss L1(α) of the active coupling model is: ； Where x1 represents an input of the array incident signal on two adjacent array elements, y1 represents the first output signal of the dual-element active coupling, G represents the gain of the forward channel, H represents the gain of the coupling channel, α represents the phase, and lg(·) represents the logarithmic function. In S13, the expression of the second output loss L2(α) of the active coupling model is: ； Where x2 represents the other input of the array incident signal on two adjacent array elements, and y2 represents the second output signal of the dual-element active coupling.

7. The method for designing a uniform array of an active coupled radar according to claim 1, wherein: In S2, the expression of the model Y of the active coupled uniform linear array is: ； ； ； ； Where, represents the active coupling matrix of the uniform linear array, represents the uniform linear array coefficient matrix, X represents the original array received signal, N A represents antenna noise, N H represents thermal noise, blkdiag{·} represents the anti-diagonal operator, Z represents the active coupling gain matrix, D represents the coefficient matrix, x1 represents the first input of the array incident signal on two adjacent array elements, and x 2M Represents the 2Mth input of the array incident signal on two adjacent array elements.

8. The method for designing a uniform array of an active coupled radar according to claim 1, wherein: The S3 includes the following sub-steps: S31. Based on the active coupled uniform linear array, an active coupled uniform planar array is constructed; S32. Split the active coupled uniform array into the x-direction and the y-direction, complete the decoupling design, and generate the final active coupled radar uniform array.

9. The method for designing a uniform array of an active coupled radar according to claim 8, wherein: In S31, the original data model W of the active coupled uniform array is expressed as: ； ； ； Where A x represents the steering vector matrix in the x direction, A y represents the steering vector matrix in the y direction, represents the Khatri-Rao product, S represents the signal matrix, N A represents the antenna noise matrix, N H represents the thermal noise matrix, s1 represents the first signal, s2 represents the second signal, s K represents the Kth target, represents the guidance vector of the first target in the x direction, represents the guidance vector of the Kth target in the x direction, Indicates the guidance vector of the first target in the y direction, Represents the guidance vector of the Kth target in the y direction.

10. The method for designing a uniform array of an active coupled radar according to claim 8, wherein: In S32, the expression for decoupling design is: ； ； ； Where W represents the original data model of the active coupled uniform array, U x represents the coupling matrix in the x-direction, U y represents the coupling matrix in the y direction, represents the active coupling matrix of the uniform linear array, represents the uniform linear array coefficient matrix, S represents the signal matrix, represents the guidance vector of the i-th target in the x direction, represents the guidance vector of the i-th target in the y direction, represents the Kronecker product, N A represents antenna noise, N H represents thermal noise, and K represents the number of targets.

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