Abstract|Concentric circular antenna array (CCAA) is synthesized
to generate pencil beam with minimum side lobe level (SLL). The
comprehensive learning particle swarm optimizer (CLPSO) is used for
synthesizing a ten-ring CCAA with central element. This Synthesis
is done by ¯nding the optimum current excitation weights and
interelement spacing of rings. The computational results show that
sidelobe level is reduced to ¡40:5 dB with narrow beamwith about
4:1±.