In this letter, we explore the potential for the application of fractal sub
arrays to the generation of sum and difference patterns. For the purposes o
f this investigation, a standard planar array is decomposed into two subarr
ays: one in the form of a Sierpinski carpet, and the other consisting of it
s complement A methodology is then introduced for feeding the two subarrays
in order to produce either a sum or a difference pattern. A particular exa
mple is considered in which directive gain plots are obtained for both the
sum and difference modes of a 27 x 27 planar array. (C) 1999 John Wiley & S
ons, Inc.