Fractal Metamaterial Antennas for Next-Generation IoT Devices: A Comprehensive Review

Abstract

Fractal and metamaterial-inspired antennas have emerged as a transformative solution for nextgeneration Internet of Things (IoT) devices, addressing the pressing demands for miniaturisation, multiband operation, high efficiency, and robust wireless connectivity. This comprehensive review synthesises recent advances in the design, analysis, and application of antennas that integrate fractal geometries with metamaterial or metasurface structures. The findings reveal that such hybrid antennas achieve significant miniaturisation and compactness, enabling integration into space-constrained IoT devices without compromising performance. They offer multiband and ultra-wideband capabilities, supporting diverse IoT standards and adaptive frequency reconfigurability. The combination of fractal and metamaterial elements enhances gain and radiation efficiency while also improving isolation and diversity in MIMO configurations, crucial for high-density, interference-prone IoT environments. Additionally, these antennas facilitate efficient energy harvesting, supporting battery-less and sustainable IoT deployments, and demonstrate robust performance in flexible, wearable, and bodyworn applications. The implications of these findings are profound: enabling ultra-compact IoT device design, supporting multi-standard and adaptive wireless protocols, improving link reliability and data throughput, reducing power consumption and supporting energy autonomy, enhancing device safety and user comfort in wearable contexts, and paving the way for scalable, high-capacity IoT networks. Future research directions include the development of tunable and reconfigurable fractal metamaterial antennas, integration with advanced materials for enhanced flexibility and biocompatibility, and the exploration of novel fabrication techniques for large-scale, cost-effective production. The continued evolution of fractal metamaterial antenna technology is poised to play a pivotal role in realising the full potential of next-generation IoT ecosystems.