Research Article On the Design and Performance Analysis of Flexible Planar Monopole Ultra-Wideband Antennas for Wearable Wireless Applications Deepa Thangarasu , 1 Rama Rao Thipparaju, 1 Sandeep Kumar Palaniswamy , 1 Malathi Kanagasabai , 2 Mohammed Gulam Nabi Alsath , 3 Devisowjanya Potti , 4 and Sachin Kumar 1 1 Department of Electronics and Communication Engineering, SRM Institute of Science and Technology, Kattankulathur 603203, India 2 Department of Electronics and Communication Engineering, College of Engineering, Guindy, Anna University, Chennai 600025, India 3 Department of Electronics and Communication Engineering, SSN College of Engineering, Chennai 603110, India 4 Department of Electronics and Communication Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Chennai 601103, India Correspondence should be addressed to Sandeep Kumar Palaniswamy; vrpchs@gmail.com Received 21 July 2022; Revised 29 August 2022; Accepted 1 September 2022; Published 26 September 2022 Academic Editor: Shobhit K. Patel Copyright © 2022 Deepa angarasu et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. With the promising developments in wearable communication technology, attention towards flexible electronics is increasing day-by-day. is study presents flexible low-profile ultra-wideband (UWB) antennas for wearable applications. e antenna comprised of a modified dewdrop-inspired radiator and a defected ground plane and has an impedance bandwidth of 3.1–10.6 GHz. e antenna flexibility is investigated using four different substrates (polyester, polyamide, denim, and Teslin) and tested on a cotton shirt and a high-end Res-Q jacket to evaluate their performance stability for body-worn applications. e fabricated planar dewdrop-shaped radiator (PDSR) antennas have a radiation efficiency of >90%, a gain of >4 dBi, and a group delay variation of fewer than 0.5 ns. e antenna conformability is measured by placing the fabricated antennas on various curved and nonplanar parts of the human body. e aforementioned antennas offer better flexibility for different bent conditions. e specific absorption rate (SAR) of the designed antennas is investigated to determine their wearability, and values are found to be less than 0.2 W/Kg. Also, the received signal strength (RSS) is discussed in order to analyze signal attenuation, and the per- formance analysis of the antennas is compared. 1. Introduction Wearable wireless electronic systems are becoming in- creasingly popular around the world. Particularly, wireless body area networks (WBANs) play a significant role in sports, healthcare, and defense applications [1, 2]. An an- tenna is an essential element in wearable electronic trans- ceivers for establishing effective communication among users. For the WBAN, an international standard IEEE 802.15.6 has been established to support both wideband and narrowband communications [3]. ough the standard includes various frequency bands, for research, the Indus- trial Scientific and Medical (ISM) band at 2.4 GHz and ultra- wideband (UWB) ranges from 3.1 to 10.6 GHz are highly preferred. Moreover, the choice of substrate is important for WBAN applications, as it should be flexible and unaffected by the aesthetic nature of human clothing. Hence, the an- tennas must exhibit better radiation characteristics even Hindawi International Journal of Antennas and Propagation Volume 2022, Article ID 5049173, 14 pages https://doi.org/10.1155/2022/5049173