A compact wearable multiband microstrip patch antenna with circuit extraction for ISM, 5G Sub-6 GHz and Wi-Fi 6E applications

This paper presents a compact, wearable multiband antenna designed for ISM (2.4 GHz, 2.1– 2.6 GHz), 5G Sub-6 GHz N79 (4.7 GHz, 4.4–5 GHz), and Wi-Fi 6E (5.9 GHz, 5.5–6.4 GHz) applications. The proposed antenna is fabricated on a low-permittivity foam substrate (εr = 1.07) with 0.05 mm copper layers. Multiband operation is achieved through optimized slots/notches in the patch while maintaining a compact size of 39.36 × 42.13 mm². Moreover, in this work we have also discussed the realization and extraction of equivalent circuit model for the presented monopole antenna. Furthermore, in this article we have also illustrated the specific absorption rate (SAR) of 1 g of tissue; the safe threshold is 1.6 W/kg, and for 10g of tissue, the safe limit is 2 W/kg, as per IEEE/European standards of the International Commission on Non-Ionizing Radiation Protection (ICNIRP).