A new sparse MIMO radar array configuration: Fulfill hole-filling without lag overlap

Simultaneously increasing degrees of freedom (DOFs) and mitigating inter-element mutual coupling is critical for multiple-input multiple-output (MIMO) radar array design. A symmetric complementarity property is revealed that symmetric lags and holes of the difference coarray (DCA) enable an enlarged virtual aperture upon translation. We mathematically prove that transmitting DCAs with this property achieve perfect hole-filling without lag overlap. Leveraging this property, a new MIMO radar array configuration is proposed by utilizing a k -times symmetric coprime array (KSCA) and a dilated hole-free six-subarray (HF6S) array as the transmitter and receiver, respectively. By achieving perfect hole-filling without lag overlap, this design simultaneously maximizes the DOFs and mitigates the mutual coupling. Simulations verify its superiority over existing configurations in both metrics.