Experimental Validation Of Coherent Multiple-Input Multiple-Output Radar Antenna Patterns

This study specifies the antenna radiation patterns of a linear array radar operating in a phased array configuration and in two colocated multiple-input multiple-output (MIMO) configurations. The MIMO-1 configuration uses orthogonal transmission on all elements, while the MIMO-2 configuration uses orthogonal transmission on the two end elements. The theoretical two-way antenna radiation patterns are derived for all three configurations. Field experiments with an eight-element, X-band linear array radar and trihedral targets are then described. The experimental mainbeam patterns are shown to match those of the theoretical patterns. MIMO-1 is shown to have the same two-way radiation pattern as that of the phased array radar configuration. Compared with MIMO-1 and phased array, MIMO-2 has enhanced angle estimation accuracy, lower gain, and higher sidelobes while only requiring two orthogonal waveforms on transmit.