Thinned MIMO arrays with constrained element spacing for imaging radar

Thinned multiple-input multiple-output (MIMO) antenna arrays with constrained element spacing are considered for imaging radar. It is shown that, in contrast to classical MIMO arrays, the minimum element spacing can be chosen to be a multiple of half the wavelength. Possible array configurations are found numerically, the minimum element spacing being set to some multiple of half the wavelength. Exemplary experimental verification is provided at K_a-band with a 4-transceiver array in a radar application.