Staircase-Enhanced Magneto-Electric Dipole Antenna for Wideband CP 5G Applications with High-Gain Arrays

This paper presents a compact magneto-electric dipole (MED) antenna optimized for wideband circularly polarized (CP) radiation for 5G applications. It incorporates a staircase-shaped electric dipole with trimmed corners to excite orthogonal modes for enhanced CP performance. The proposed single-layer MED antenna achieves a (Formula presented.) wide-impedance bandwidth ((Formula presented.) dB, (Formula presented.) – (Formula presented.) GHz) and (Formula presented.) CP bandwidth ((Formula presented.) dB, (Formula presented.) – (Formula presented.) GHz) with a compact footprint of (Formula presented.). There is a symmetrical radiation pattern with a co-to-cross polarization ratio (Formula presented.) dB and a stable gain of (Formula presented.) dBi. An equivalent circuit model is optimized via particle swarm optimization (PSO). The optimized MED antenna is utilized to investigate various CP-MIMO configurations and wideband sequential arrays. Next, a (Formula presented.) CP-MIMO antenna system is developed, employing polarization diversity in parallel and mirror configurations. Isolation is improved by etching a ground slot between the MED elements, yielding isolation levels of below (Formula presented.) dB and (Formula presented.) dB, respectively. Further, a (Formula presented.) CP-MIMO configuration is designed and evaluated. This arrangement demonstrates an envelope correlation coefficient (ECC) of (Formula presented.) and a diversity gain of approximately 10 dB across the operating bandwidth. Finally, a sequential array is designed that applies a (Formula presented.) sequential rotation and phase excitation to MED elements for high-gain CP 5G communications. Here, various array sizes are evaluated, with an (Formula presented.) MED array providing CP radiation ((Formula presented.) dB) from 20 to 30 GHz with enhanced impedance and axial ratio bandwidths and stable gain with a peak value of (Formula presented.) dBi.