A new type of dual-band circularly polarized antenna based on fractal structure

In this article, by computer simulation and actual fabrication, it is demonstrated that dual-band operation with circular polarization of radiation may be achieved by the combination of Sierpinski fractal and L-shaped stub feed-line with a circle slot radiator realized on a two layer microstrip antenna. The two parallel plates only 0.10λ apart as proposed antenna is compact, which has a total size of only 0.54λ ×0.5λ×0.14λ. The fabricated prototype exhibited good impedance bandwidth, and measured performances are 9% (3.2-3.5 GHz) and 14.3% (6.5-7.5 GHz) for 3-dB AR bandwidths for the 3.3 and 7.0 GHz bands. In addition, good antenna performances such as radiation patterns and antenna gains over the operating bands have been obtained.