A Novel Metasurface Antenna With Enhanced CP Bandwidth Through Decreasing <i>Q</i> Factor

ABSTRACT This letter presents a novel metasurface antenna with improved axial ratio bandwidth using parasitic annular sector strips which decreased the Q factor. First, a metasurface antenna composed of a circular patch with etched annular cracks was designed and analyzed through characteristic analysis. Later, to enhance the axial bandwidth, four annular sector parasitic strips were added to decrease the Q factor based on transmission line analysis. In the end, the proposed antenna is fabricated and measured. The results show that the proposed antenna operates in the frequency band from 8.77 to 9.68 GHz; its 3 dB axial ratio bandwidth is 9.19–9.62 GHz, which is significantly improved by 119% compared to the case without the parasitic strips; the maximum gain is 7.2 dBic, which makes it a good candidate for marine search and rescue communications.