A Fractal Dual-Band Polarization Diversity Antenna Array for 5G Communications

This paper introduces a compact dual-polarized antenna array designed for the 28/38 GHz frequency bands. The dimensions of the antenna array are 32×20 mm
²
, offering two broad impedance bandwidths: 2.7 GHz (26.6‒29.3 GHz) and 5.2 GHz (35‒40.2 GHz). To achieve polarization diversity, the antenna is excited by two orthogonal feed lines. Each element of the antenna array comprises a fractal radiating patch, enabling multiple resonances, and a rectangular slot in the radiating patch, enhancing the antenna's impedance bandwidth. The proposed antenna array exhibits unidirectional radiation patterns with gains of 13 dBi and 12.5 dBi at the lower and upper frequency bands, respectively. Furthermore, the isolation between the ports exceeds −10 dB for both operating bands. With its simple structure, compact size, and high gain, the proposed antenna is deemed suitable for integration into 5G communication systems.