A semi-ellipsoid surface conformal array arrangement method based on a standardized subarray

Abstract

The application provides a semi-ellipsoid surface conformal array arrangement method based on a standardized subarray, and the arrangement parameters are obtained by establishing a constraint relationship of subarray coordinates on a semi-ellipsoid surface and according to an antenna gain index and fluctuation requirements, so that the purpose of full-space efficient coverage arrangement is achieved. The application firstly constructs a semi-ellipsoid surface based on an ellipsoid formula, and then arranges the subarrays in layers and at equal intervals on the semi-ellipsoid surface, secondly, the relationship formulas of a semi-ellipsoid long semi-axis, a semi-ellipsoid short semi-axis, a subarray layer number, a subarray number of each layer, a radius of a circle where each layer of subarrays is located, a subarray height, a subarray inclination angle and a subarray azimuth angle are established, then the element position coordinates of each subarray on the curved surface are calculated by performing three-dimensional coordinate rotation and translation on the horizontal reference subarray coordinates, and finally, the purpose of being universally applicable to the arrangement of different aperture spherical conformal arrays is achieved based on the minimization of the fluctuation of the antenna gain curve, so that the application can be applied to the curved surface conformal array arrangement in the field of full-space phased array antenna communication measurement and control.

Description

TECHNICAL FIELD

[0001] The application relates to an array antenna arraying method in the field of phased arrays, in particular to a curved surface conformal array arraying method in the field of communication measurement and control of full-space phased array antennas. BACKGROUND

[0002] A full-space multi-beam phased array system is more and more favored due to the characteristics of flexible electric beam scanning, simultaneous multi-target tracking in a full-space range and the like. The curved surface shape and scale of phased array antenna arrangement determine the antenna gain and implementation cost. How to arrange the phased array antenna is the first important problem faced by the full-space multi-beam phased array system, so the spherical conformal array arraying method is particularly important.

[0003] At present, common spherical conformal array arraying methods include a unit-level arraying method, a polygon arraying method and the like. The unit-level arraying method arranges the array elements on a spherical curved surface with a single array element as a granularity. The advantage is that the antenna scanning gain curve is relatively smooth, and the disadvantage is that the arraying granularity is too fine, which poses challenges to the beam forming algorithm, assembly, testing and maintenance. The polygon arraying scheme arranges the spherical curved surface based on triangular, pentagonal or hexagonal sub-arrays. This method reduces the arraying granularity by referring to the football splicing method, but the triangular, pentagonal or hexagonal shapes are not regular enough. With the change of the system antenna gain requirement, the size of the sub-array needs to be adjusted, which increases the design complexity of the phased array components, printed boards and the like. SUMMARY

[0004] Therefore, the technical problem to be solved is to propose a spherical conformal array arraying method which can reduce the system complexity and is universally applicable under the conditions of meeting the antenna gain and scanning smoothness.

[0005] The technical scheme adopted by the application is as follows:

[0006] A semi-ellipsoidal curved surface conformal array arraying method based on a standardized sub-array, comprising the following steps:

[0007] (1) constructing a semi-ellipsoidal curved surface based on an ellipsoidal formula, dividing the sub-arrays into a plurality of layers based on the semi-ellipsoidal curved surface, equally spacing the sub-arrays in each layer, and placing the centers of the sub-arrays on the semi-ellipsoidal curved surface, and the planes of the sub-arrays are tangent to the semi-ellipsoidal curved surface;

[0008] (2) calculating the height of the center of each layer of sub-arrays according to the radius of the circle where the center of each layer of sub-arrays is located;

[0009] (3) calculating the inclination angle of each layer of sub-arrays according to the radius and height of the circle where the center of each layer of sub-arrays is located;

[0010] (4) calculating the azimuth angle of each sub-array in each layer according to the number of each layer of sub-arrays;

[0011] (5) setting a horizontal plane reference subarray coordinate, calculating the element position coordinates of each subarray on the curved surface according to the radius, height, inclination angle and azimuth angle of the center of each subarray through three-dimensional coordinate rotation and translation;

[0012] (6) calculating a directional pattern function according to the element position coordinates of each subarray and the scanning direction;

[0013] (7) judging whether the gain curve meets the threshold requirement according to the directional pattern function, if yes, completing the array arrangement of the semi-ellipsoid curved conformal array, otherwise, adjusting the semi-ellipsoid major axis, semi-ellipsoid minor axis, subarray layer spacing and the number of subarrays in each layer, and returning to step (2).

[0014] Compared with the background art, the present application has the following advantages:

[0015] (i) the present application proposes a semi-ellipsoid curved conformal array arrangement method based on standardized subarrays, the gain fluctuation of the antenna in each direction is relatively small, and an effective array arrangement method is provided for full-space coverage of large phased array antennas.

[0016] (ii) the present application uses standardized subarrays, and the complexity of beam forming algorithm, assembly, testing and maintenance is relatively low, thereby reducing the engineering implementation cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The present application is a processing flow chart.

[0018] Figure 2 The present application is a side view of an array arrangement simulation example.

[0019] Figure 3 The present application is a perspective view of an array arrangement simulation example.

[0020] Figure 4 The present application is an antenna gain fluctuation diagram. DETAILED DESCRIPTION

[0021] The present application will be further described below in combination with specific implementation steps:

[0022] The present application is a semi-ellipsoid curved conformal array arrangement method based on standardized subarrays, first, a semi-ellipsoid curved surface is constructed based on the ellipsoid formula, and subarrays are layered and equally spaced on the semi-ellipsoid curved surface, second, the relationship formulas of the semi-ellipsoid major axis, semi-ellipsoid minor axis, subarray layer number, subarray number in each layer, subarray radius in each layer, subarray height, subarray inclination angle and subarray azimuth angle are established, then the element position coordinates of each subarray on the curved surface are calculated through three-dimensional coordinate rotation and translation of the horizontal reference subarray coordinate, and finally, based on the minimization of the antenna gain curve fluctuation, the purpose of universally applicable array arrangement of different aperture spherical conformal arrays is achieved.

[0023] REFERENCE Figure 1, the specific steps include:

[0024] ①Based on the ellipsoid formula to build semi-ellipsoid surface, based on semi-ellipsoid surface, the sub-array is divided into several layers, each layer of sub-array is equidistantly distributed, and the center of the sub-array is placed on the semi-ellipsoid surface, and the sub-array plane is tangent to the semi-ellipsoid surface; Where the semi-ellipsoid height is represented by r b , the semi-ellipsoid bottom radius is represented by r a , the sub-array is uniformly distributed in N layers, the layer number is n=1,…,N, and the number of sub-arrays in each layer is M n .

[0025] ②According to the radius of the circle where each layer of sub-array center is located, the height of each layer of sub-array center is calculated, assuming that the radius of the circle where the n layer sub-array center is located is r n , then the expression of the height h n of the n layer sub-array center is:

[0026]

[0027] ③According to the radius and height of the circle where each layer of sub-array center is located, the inclination angle θ n of each layer of sub-array is calculated;

[0028] The expression is:

[0029]

[0030] ④The azimuth angle of the n(n=1,…,N) layer and the m(m=1,…,M n )th sub-array is calculated

[0031] The expression is:

[0032]

[0033] ⑤Set the horizontal plane reference sub-array coordinates

[0034]

[0035] In the formula, p=1,…,N p , N p is the number of sub-array elements; Through three-dimensional coordinate rotation and translation, the element position coordinates of each sub-array on the curved surface are calculated as:

[0036]

[0037] ⑥According to the element position coordinates of each sub-array and the scanning direction, the directional pattern function is calculated as

[0038]

[0039]

[0040] In the formula, ω n,m,p is a weighting coefficient, θ0 is a scanning azimuth angle, is a scanning elevation angle.

[0041] V. According to the directional diagram function, it is judged whether the gain curve meets the threshold requirement, if yes, the half-ellipsoid curved surface conformal array is completed, otherwise, the half-ellipsoid long semi-axis, short semi-axis, interlayer distance of subarray and the number of subarrays in each layer are adjusted, and the step 2 is returned.

[0042] Figure 2 is a side view of the array simulation example of the application, Figure 3 is a perspective view of the array simulation example of the application, in which Figure 2 and Figure 3 For example, the length ratio of the ellipsoid long semi-axis and short semi-axis is 4:3, the standardized subarray scale is 4x4, and the half-ellipsoid curved surface is divided into 8 layers. From top to bottom, the layer number n is 1-8, and the number of subarrays M n is 1, 4, 8, 12, 16, 20, 24 and 24 respectively, the azimuth angle of each layer of subarrays can be substituted into the formula of step 4 to calculate, the height of each layer is 1.60, 1.53, 1.40, 1.20, 0.95, 0.68, 0.39 and 0.09 respectively, and the inclination angle of each layer is 0°, 18.6°, 35.2°, 49.0°, 60.5°, 70.3°, 79.2° and 87.4° respectively. The array directional diagram is simulated, Figure 4 is the antenna gain fluctuation diagram of the application, in which the antenna gain meets the requirement of ≥30dB in the range of antenna elevation angle 5° and azimuth angle 0°-360°, the gain is continuous and has no step jump, and the gain fluctuation range is ≤±1dB.

[0043] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the application but not limit the application, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions, which should be covered in the scope of the claims of the application.

Claims

1. A method for arranging a conformal array on a semi-ellipsoidal surface based on standardized subarrays, characterized in that, Includes the following steps: (1) Construct a semi-ellipsoidal surface based on the ellipsoidal formula, divide the subarray into several layers based on the semi-ellipsoidal surface, distribute the subarrays at equal intervals in each layer, place the center of the subarray on the semi-ellipsoidal surface, and make the subarray plane tangent to the semi-ellipsoidal surface. (2) Calculate the height of the center of each subarray based on the radius of the circle containing the center of each subarray. (3) Calculate the tilt angle of each subarray based on the radius and height of the circle where the center of each subarray is located; (4) Calculate the azimuth angle of each subarray in each layer based on the number of subarrays in each layer; (5) Set the horizontal plane reference subarray coordinates, and calculate the array element position coordinates of each subarray on the curved surface by rotating and translating the three-dimensional coordinates based on the radius, height, tilt angle and azimuth angle of the circle where the center of each subarray is located; (6) Calculate the pattern function based on the element position coordinates and scanning direction of each subarray; (7) Determine whether the gain curve meets the threshold requirement based on the radiation pattern function. If it does, complete the conformal array layout of the semi-ellipsoidal surface. Otherwise, adjust the semi-major axis, semi-minor axis, subarray spacing and number of subarrays per layer of the semi-ellipsoid, and return to step (2).

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