A dual-band dual-sense circularly polarized square-ring slot antenna

A new dual-band dual-sense circularly polarized (CP) square-ring slot antenna is designed in this paper. By notching two square-ring slots in the ground plane, and changing the gap width in one of the diagonals of the two slots to achieve dual-band CP radiation. If the perturbations of the two slots are symmetrically placed about the microstrip feeding line, then a dual-sense CP radiation is obtained. The proposed antenna is implemented and measured. Simulated and measured results show that the antenna is with good circularly polarized radiations at the two resonant frequencies.