The structure problems of non-uniformly spaced array used in adaptive super-angle-resolution(SUAR) are discussed in this paper. It is shown that the performances of the angle spectrum of eigenvector algorithms，under some conditions，are determined completely by array factor. Analyses and simulations have illustrated that the linear minimum redundancy (LMR) array is a kind of SUAR array with good performances. It is also shown that some kinds of non-uniformly spaced array，which is the same as uniformly spaced array，have the problem of grating lobes. In this paper，a fomula of the unit length of the array to avoid grating lobes is presented.