For Future Wireless Communications: Development of A Circularly Polarized Antenna with Low Profile

In this study, a Coplanar waveguide circularly polarized (CPW-CP) antenna with a novel low profile and wide 3dB-AR bandwidth is introduced for use in wireless communications. The proposed antenna design consists of a semicircular strip that is combined with a horizontal strip extension to form an inverted G in shape. The antenna’s CPW is loaded with three spiral rings on the left side and three slot rings on the right side, all interconnected to attain right-hand circular polarization (RHCP). The design is optimized in terms of impedance matching bandwidth, 3dB axial ratio (AR) bandwidth, radiation efficiency, and maximum gain, and its performance is evaluated through both simulations and experimental measurements. The proposed antenna operates within the frequency band covering the 5.0-7.2 GHz 3dB-AR bandwidth which corresponds to about 36% and 4.8-9.4 GHz impedance matching bandwidth. The achieved maximum gain and radiation efficiency are 2.5 dBic and 99%, respectively, and the overall antenna dimensions are $25\times 25\times 0.2$ mm3, resulting in a bandwidth-dimension ratio (BDR) of 1040.