The application of CLPSO to design CCAA has been demonstrated in
this paper. Compared to the original PSO, CLPSO solving multimodal
problems. CLPSO is best suited for solving multimodal problems
that are common in several antenna design. The optimal design of
a ten-ring CCAA with central element has been described. This
optimal design is done by ¯nding optimal excitation currents and
optimal interelement spacing of rings. The simulated results reveal
that the optimal design o®ers a considerable SLL reduction along
with reduction of HPBW compared to the corresponding UCCA. The
minimum achieved sidelobe level is