Notes on synthetic phased-array with 2-D sparse arrays.

Recent advances in 3-dimensional (3-D) imaging with 2-D sparse arrays have generated renewed interest in array synthesis theory. The 3-D imaging with arbitrary planar line shapes is particularly interesting. In this correspondence, we clarify some points presented in recent publications and show that aperture synthesis can be viewed with a very simple, physical approach. Its limitations due to approximations also will be discussed.