There is provided an array antenna and a system and a method for element configuration in an array antenna. The antenna elements are determined to be active based on meeting constraints, including at least one of: for concave portions of the surface, a maximum slope difference between active antenna elements is less than a predetermined value; a maximum element spacing between active antenna elements is greater than or equal to half a wavelength of a signal propagating or received at the respective antenna elements; and for antenna elements grouped into subarrays that each transmit a unique data stream, the number of subarrays being between two and a maximum number of subarrays, the maximum number of subarrays comprising a total number of antenna elements that provide multiple-input and multiple-output (MIMO) operation for multiple locations.