Abstract

The rapid advancement of fifth-generation (5G) and emerging sixth-generation (6G) wireless communication systems has increased the demand for compact, efficient, and multi-band antenna technologies capable of supporting diverse communication services and applications worldwide today. Fractal antennas have gained considerable attention owing to their self-similar and space-filling geometrical characteristics, which enable antenna miniaturization while maintaining desirable electromagnetic performance parameters. This review presents a comprehensive assessment of multi-band fractal antennas developed for 5G and beyond wireless networks. Various fractal geometries, including Koch, Sierpinski, Hilbert, Minkowski, and Peano structures, are analyzed with respect to operating frequency, bandwidth, gain, radiation efficiency, return loss, and size reduction capability. The review further examines recent advancements involving metamaterial integration, defected ground structures, multiple-input multiple-output (MIMO) configurations, and artificial intelligencebased optimization approaches for antenna performance enhancement. Comparative analyses of sub-6 GHz and millimeter-wave fractal antenna designs are conducted to evaluate their effectiveness in meeting next-generation communication requirements. Additionally, key challenges such as fabrication complexity, mutual coupling, and bandwidth limitations are discussed. Finally, future research opportunities involving reconfigurable antennas, programmable metasurfaces, terahertz communication systems, and design frameworks are highlighted.