ULA Fitting for Sparse Array Design

Sparse array (SA) geometries, such as coprime and nested arrays, can be regarded a concatenation of two uniform linear arrays (ULAs). Such lead to significant increase the number degrees freedom (DOF) when second-order information is utilized, i.e., they provide long virtual difference coarray (DCA). Thus, idea this paper based on observation that SAs fitted through sub-ULAs. A corresponding SA design principle, called ULA fitting, then proposed. It aims from Towards goal, polynomial model for used, it, DCA structure analyzed if composed multiple with low mutual coupling considered. fitting enables transfer requirements, hole free, other into pseudo equation, hence, find particular solutions. We mainly focus designing large DOF. Two examples closed-form expressions are developed fitting. Numerical experiments verify superiority proposed in presence heavy coupling.