An Amc-Based Circularly Polarized Antenna For 5g Sub-6 Ghz Communications

This paper presents an AMC (artificial magnetic conductor)-based wideband circularly polarized printed monopole antenna for unidirectional radiation. The antenna includes an AMC reflector, a coplanar waveguide (CPW) feed structure to excite the antenna, a ground plane with a rectangular slot on the left side of feedline, and an asymmetrical ground plane on its right side. The induced surface currents on CWP feedline, rectangularly slotted, and asymmetrical ground planes cause circularly polarized radiations. The AMC reflector consisting periodic metallic square patches is used instead of the conventional PEC (perfect electric conductor) reflector, the distance between the antenna and reflector is reduced from 0.25 lambda 0 to 0.18 lambda 0 with performance improvement. By incorporating AMC layer with the monopole antenna, the gain of antenna is increased from 3.3 dBic to 8.7 dBic while the axial ratio bandwidth (ARBW) of antenna is increased from 27.27% to 51.67%. The simulated and measured results show that the proposed antenna has an overlapping 10-dB |S11| and 3-dB ARBW of 51.67% (3.0-5.09 GHz). The overall dimensions of monopole antenna backed by AMC reflector is 1.20 lambda 0 x 1.20 lambda 0 x 0.21 lambda 0 and covers 5G sub-6 GHz new radio bands (n77/n78/n79) for wireless communication systems.