Miniaturized circularly polarized microstrip antenna by spirally slotted

A miniaturized circularly polarized microstrip antenna is designed by spiral which is a typical frequency independent structure. A rotated corner-cut square radiator is used to implement the CP radiation. The ground plane of the antenna is spirally slotted to enhance the operating band and achieve the miniaturization. The radiation performances of the proposed are analyzed by comparing with a reference antenna which is not slotted. The results show that the impendence bandwidth is 2.362GHz-2.466GHz and the axial ratio bandwidth is 2.403GHz-2.427GHz, which are lower than those of the reference antenna.