  Application of range-angle focusing frequency diverse array (FDA) for secure
wireless communication has been proposed in recent years. However, it can be
proven that the FDAs are not suitable for secure wireless communication and the
same properties of the focusing FDA can be obtained by using traditional phased
arrays, more effectively. Besides, in this paper, it is indicated that FDAs are
not good candidates for constructing time-variant focusing beampatterns, while
constructing time-invariant focusing beampatterns is impossible at all.
Furthermore, some incorrect considerations about the FDAs are highlighted.
