This paper presents a low-profile, broadband, circularly polarized (CP) antenna. It is composed of a single-feed crossed dipole loaded with four parasitic patches. Due to the presence of parasitic patches, the antenna achieves a low profile and a broadband characteristic in terms of impedance matching and CP radiation bandwidth. The final design, which has an overall size of 120 mm × 120 mm × 16.3 mm (0.64λ0 × 0.64λ0 × 0.087λ0 at 1.6 GHz), yields a -10 dB impedance bandwidth of 1.39-1.75 GHz (22.93%), a 3-dB axial ratio bandwidth of 1.472-1.684 GHz (13.4%), a right-hand CP broadside gain of > 8.4 dBic, and a radiation efficiency of > 96%.
This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 102.04-2016.02. This research is also supported by the Institute for Information & Communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (No. 2017-0-00959, University ICT Basic Research Lab) and \Human Resources Program in Energy Technology\ of the KETEP, granted financial resource from the Ministry of Trade, Industry & Energy (No. 20164030201380).