Wearable Plant-Shape Bioinspired PCB Antennas for 5G Band at 3.5 GHz

The technology of cellular communication for the fifth generation, 5G, is used in several applications that require high speed data, broadband, and low latency, such as Industry 4.0, wireless sensor networks, high-speed mobile communications, smart cities, smart grids, and other emergent technologies. Antennas for wireless wearable devices are required to have a compact structure and withstand temperature variations and mechanical tensions. The use of bioinspired plant shapes in the printed circuit board (PCB) antenna technology enables the development of compact devices, featuring omnidirectional radiation pattern, and wideband. This work introduces a type of PCB antenna, flexible and wearable, bioinspired on Neem plant-shapes ( Azadirachta indica ), applied to 5G band at 3.5 GHz, operating in the range of 3.3 GHz to 3.6 GHz. The antennas are built using polyamide as a dielectricin polyamide dielectric, a flexible material resistant to high temperatures and mechanical tensions, with the plant shape generated by the Gielis formula. The wearable bioinspired antennas feature a wideband characteristic, with measured bandwidth of over 500 MHz, a compact structure measuring 23.36 mm in length and 17.52 mm in width, an omnidirectional radiation pattern, a half power beamwidth of 84 degrees, a maximum gain of 2.03 dBi, and coverage of the 5G band at 3.5 GHz. Simulation results show that displacement of the ground plane affects the resonance frequency, with optimal results at a distance of 1 mm.