Performance comparison of different sparse array configurations for ultra-wideband, near-field imaging applications

The aim of this study is to compare the performance of different multiple-input multiple-output (MIMO) array topologies, intended to be used in ultra-wideband (UWB) near-field imaging applications, by using an analysis method that does not include the effects of image reconstruction algorithm. For this purpose, maximum projection method, previously proposed for the analysis of UWB arrays under far-field conditions, is utilized and modified to obtain two way beam patterns of UWB arrays operating in the near-field. The side lobe levels of these beam patterns are shown to be a clear performance criterion for evaluating the performance of sparse antenna arrays. Numerical simulation results are compared with previously reported results for some commonly used array configurations and a good agreement is observed.