Design of Circularly Polarized Hexagonal Ring Microstrip Antenna for 5G Mobile Applications

A compact, low-profile, single-feed circularly polarized hexagonal ring microstrip antenna (HRMA) is presented for 5G mobile applications, covering the n78 frequency band. The HRMA is designed to operate in the fundamental mode and is fed using a proximity-coupled line. The orthogonal mode is generated by inserting rectangular and circular slits along the periphery of the inner hexagonal ring to achieve circular polarization. Additional resonances are created by placing the shorting vias that lead to bandwidth enhancement. The proposed antenna design achieves a bandwidth of 186 MHz, an axial ratio of 2.5 dB with LHCP, and a stable gain of 7 dB over the frequency range of 3.4-3.6 GHz.