Low-grating lobe configuration method of three-dimensional imaging radar two-dimensional sparse array

Abstract

The invention provides a low-grating lobe configuration method of a three-dimensional imaging radar two-dimensional sparse array. According to the method, a plurality of rotating arms are adopted, and strong grating lobes caused by a sparse array can be inhibited, and the inhibition performance of an imaging radar for false targets can be improved. The method includes the following steps that: the number of array elements contained by each rotating arm and the total number Narm of rotating arms are determined according to a given total number of array elements; one rotating arm is designed according to a Fibonacci array, the positions of array elements are represented by polar coordinates (r, theta), wherein the radius r is the linear function of the square root of the serial number of the array elements, and the angle theta of the array elements is increased linearly with the serial number of the array elements; and the rotating arm is rotated around the center of the array by 2pik/Narm(k=1,...,Narm-1), and a final array can be obtained. According to the method of the invention, the multi-rotating arm array of a rotary and symmetrical structure is designed, the number of array elements of which the projections are overlapped in any directions is small, and therefore, the problem of array element masking of a conventional two-dimensional array configuration method can be well solved, and a directional diagram with a low grating lobe level can be obtained, and detection for targets can be benefitted, and false targets can be inhibited.

Description

technical field [0001] The invention belongs to the field of three-dimensional imaging radar, and in particular relates to a method applicable to two-dimensional sparse array configuration. Background technique [0002] In order to ensure a certain azimuth resolution, the radar array must have a sufficiently large size; on the other hand, in order to save the cost of the 3D imaging radar and speed up signal processing, the radar uses a smaller number of antennas. In this way, the radar array is sparse, and the antenna spacing is greater than half a wavelength, and grating lobes will appear, resulting in false targets and seriously affecting radar performance. Therefore, the suppression of grating lobes has become an urgent problem for sparse array radars. [0003] The grating lobes are formed by the coherent superposition of the signals transmitted by each antenna. Therefore, the array configuration can be used to design appropriate array element positions and array element...

AI Technical Summary

Problems solved by technology

[0009] However, when there are not many antennas, the array does not fully satisfy the statistical characteristics of the Fibonacci array, and there may still be more serious array element shadowing effects in some directions, and the grating lobe level is relatively high

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