Comparison of near and far field focusing patterns for two-dimensional sparse MIMO arrays

In this paper, the far field and near field point spread functions as focusing patterns are investigated for two dimensional (2-D) sparse multiple input multiple output (MIMO) arrays, namely, rectangular array and curvilinear array in millimeter-wave range from 120 GHz to 140 GHz. The point spread functions are obtained by simulation. The results show that comparing the curvilinear with the rectangular array, the curvilinear design is superior in both far and near fields. Another interesting result is that in the near field, grating/side lobe level decreases, dramatically, for both arrays.