Design Optimization for Enhancing Microstrip Antenna Performances Using Polylactic Acid (PLA) Biopolymer Substrate in Sub-6 GHz Band

The wireless technology is witnessing two interconnected trends that have significant implications. Firstly, there is an ever-increasing demand for high-speed data transfer and extensive bandwidth, driven by the rapid expansion of modern smart applications. This relentless demand has forced new wireless networks, such as 5G and 6G, to explore new frequency bands, such as Sub-6 GHz, to accommodate the surging data requirements. Secondly, the remarkable growth in applications with stringent environmental conditions, extending beyond healthcare and biomedical research, to industries such as industrial automation, environmental monitoring, agriculture, transportation, and smart cities, demand wireless devices and communication technologies that can function optimally in delicate and sensitive environments, without compromising on performance. Hence, the simultaneous growth of these trends highlights the critical significance of incorporating eco-friendly and environmentally adaptable polymers in the design of new antennas. This approach becomes essential to ensure the development of resilient and flexible wireless devices that can function optimally in diverse and challenging environments. The present work delves into the performance analysis of rectangular and circular microstrip antennas design for sub-6 GHz band. The specific areas of interest include investigating how the thickness of the PLA (Polylactic Acid) substrate influences antenna design and employing Carbon Nanotubes (CNTs) as the conductive material for both the antenna feed and the ground plane. The combined use of PLA and CNTs resulted in compact circular and rectangular antennas, with dimensions of 25.8 x 45.8 mm2 and 26.4 x 42.1 mm2, respectively. Notably, both antennas exhibited an impressive realized gain exceeding 4.9 dBi and an efficiency surpassing 73% at 5.8 GHz, demonstrating robust performance under various substrate thicknesses, including flat and bending scenarios. These outstanding outcomes position the proposed microstrip antennas as highly suitable candidates for a broad spectrum of emerging applications within the sub-6 GHz band.