Abstract
A printed dual-band circularly polarized (CP) antenna is presented. The antenna is composed of a strip monopole on one side of a substrate. On the other side of the substrate, there are a perturbed patch and a slotted ground plane. Two sleeves are extended from two edges of the ground plane. It is investigated that the perturbed patch is mainly responsible for the CP wave centered at 5.5 GHz and the sleeves are mainly responsible for the CP wave centered at 2.5 GHz. The measured boresight gains are 4 dBic at 5.5 GHz and 2.5 dBic at 2.5 GHz.