An MIMO array for high-resolution sector-scan imaging

For increasing the cross-range resolution of the sector-scan imaging system, a multiple-input multiple-output (MIMO) array with high cross-range resolution is designed in this paper. Firstly, the general equialent model for both narrowband and wideband signals between the MIMO array and its virtual array is established. When transmitting waveforms have good auto- and cross-correlation properties, the outputs of matched filters of the MIMO array are equivalent to the range-compressed echoes of a single-input multiple-output (SIMO) array and hence. In this case, the MIMO array is equivalent to a virtual array. Then, basing on the equivalence the analytical solutions of coordinates of virtual transmitting and receiving elements are given based on the equivalence. Then, under the condition of using constant array physical size, a new MIMO array composed of two transmitting elements and N-element receiving uniform linear array (ULA) is designed. Theoretical analysis and numerical simulations show that the designed MIMO array obtains the best cross-range resolution, when compared to the SIMO array and other MIMO array layouts with the same physical size.