Enhanced Maximum Interelement Constrained Array Design via Simple Hole-Filling Strategy

In this paper, we propose a new sparse array design via the maximum interelement spacing constraint (MISC) criterion. The array, called enhanced MISC array (xMISC), is developed by filling the holes in the conventional improved MISC array (IMISC). First, the hole locations in the IMISC array are analyzed, then a simplified hole-filling strategy is proposed. Compared to the existing MISC and IMISC arrays, the xMISC array exhibits enhanced uniform degrees of freedom (uDOF) and relatively reduced mutual coupling. Besides, the xMISC retains a hole-free difference co-array. Moreover, the closed-form expressions for sensor locations, weight functions, and achievable DOF are derived in detail. Numerical examples validated the merits of the xMISC array.