Wideband And Wide-scan Angle Sparse Array Synthesis

In recent years,with the increasing use of array antennas in wireless systems such as electronic detection,radar detection,imaging and wireless communication,the performance requirements of array antennas are becoming higher and higher,and array antennas are moving toward large-scale and broadband.The direction of the frequency band is developing.In engineering,the high cost of large array antennas restricts its application and development.Sparse arrays can greatly reduce the hardware and software complexity of array antennas.However,many existing sparse array synthesis methods have their own shortcomings.This paper starts from practical applications and studies some key issues in array synthesis.Specifically,the method includes: ensuring array performance after the number of array elements is greatly reduced,and limiting the minimum array element spacing between the sparse array elements,so that the sparse array has the characteristics of wideband and wide-angle scanning.Firstly,for the sparse array synthesis problem of single frequency points,in order to keep the sparse array unchanged,a sparse array synthesis model of perturbed compressed sampling(PCS)is established.By solving this problem,sparse arrays with performance not weaker than uniform half-wave full arrays can be obtained.The only problem is that the inter-element spacing of the array is too small to be used in practice.To this end,an elements merging method similar to finding the center of gravity is adopted,so that the minimum spacing of the array satisfies the demand while further reducing the number of array elements.In order to make the performance of the array after the array layout adjustment is not affected,a process of convex optimization secondary synthesis is added to obtain a complete algorithm.The performance of the algorithm is verified by a largescale planar array,scannable planar array,and shaped planar array.Then,for the current comprehensive method,the bandwidth is rarely considered.Combined with the fractal and global optimization algorithm,a wide-bandwidth sparse array synthesis method is proposed.The line array,the planar array and the sub-array are synthesized separately,and the synthesized arrays can ensure that the low-frequency halfwavelength is used as the minimum array element spacing,and the scanning is performed at any angle in the frequency range of two times to twenty times or higher with no grating lobes.In the synthesis of line arrays,two different scale examples are used to verify the advantage of fractal efficiency.In the synthesis of planar arrays,the performance of the algorithm is also verified by a large-planar array.In the sub-array synthesis,in addition to splicing small-scale subarrays into a larger array,a method of rotating subarrays is added to further depress the side lobes.Finally,the multi-objective optimization algorithm is extended to the synthesis of wide-bandwidth and wide-scan angle arrays.By combining fractal and decomposition-based multi-objective evolutionary algorithms,many wide-bandwidth and wide-scan angle arrays can be obtained at the same time.Each array has different performance indicators.The respective advantages,the designer can choose according to the actual needs,avoiding the work of repeated section fitness weights in the single-objective optimization algorithm,and further improve the efficiency of the algorithm.