Performance Analysis of a Compact and Conformal Super Wide Band Textile Antenna for Wearable Body Area Network Applications Md. Shaad Mahmud Shuvashis Dey Department of Electrical & Electronic Engineering Department of Electrical & Electronic Engineering American International University-Bangladesh (AIUB) American International University-Bangladesh (AIUB) Dhaka, Bangladesh Dhaka, Bangladesh shaadmahmud@yahoo.com shuvashisdey@yahoo.com Abstract: In this article, a novel and compact super wide band (SWB) planar and conformal textile antenna structure is presented. The increasing interest in wearable personal area networks in civil, medical, sport wear and military domains promises to replace wired- communication networks in the near future in which antennas play a paramount role. In this antenna, the substrate is made from jeans material while patch and ground is made out of copper tape. This antenna resonates at frequencies from 1.8GHz to 23.8 GHz. Here, the performance of this antenna in terms of resonance frequency fluctuations, return loss and radiation pattern deformation at different bending angles is observed as well. Key words: Super Wide Band, conformal, textie antenna, resonance frequency, microstrip-feed, Partial ground plane I. INTRODUCTION Body area networks (BAN) are a natural progression from the personal area network (PAN). This network enables wearable computer devices to interact with each other and exchange digital information using the electrical conductivity of the human body as a data network [1]. Wearable intelligent textile system is an innovative fast growing field in application oriented field [3]. The antenna is a fundamental part of wireless body area networks. Textile antenna is one of the most fascinating and cutting edge research areas of modern era. Enhancement in communication and electronic technology has enabled the development of compact and intelligent antenna devices which can be positioned on the human body or implanted inside it. [4] Miniaturization in microelectronics along with other technologies allows these antennas to integrate into clothing paving the way to the development of wearable wireless devices. The textile antenna system can be used for a wide variety of applications including a more comfortable solution for real time physiological measurements systems, pulse rate monitoring in sports, and navigation support in the car and so on. They can also be used to keep continuous record of wearer’s health by monitoring their vital signs. Textile antennas also assist the emergency services such as fire fighters, detective and police [5]. The appearance of wearable intelligent textile systems revealed the necessity for WBAN (Wireless Body Area Network) system to provide standalone outfit in recent years.[1] UWB antennas for body-centric wireless communications as well as the bending effect of these antennas have been presented extensively in the open literature recenty[1-2]. But very few people have discussed about SWB antennas, especially about the bending effect of antenna for SWB body centric communications. There are several definitions of bandwidth circulated among our antennas and propagation society; the two definitions, that most frequently used, are the percent bandwidth and the ratio bandwidth. The ratio bandwidth is defined as follows: B R = BW / f L  Where BW is the nominal bandwidth defined by BW = f H – f L Here, f H , f L are the maximum and minimum frequency at -10 dB, respectively, BR is the ratio bandwidth, commonly noted as BR = R: 1, where R is the ratio defined as R= f H /f L . The term SWB is used to indicate a greater bandwidth than a decade bandwidth that is it is often used for describing a ratio bandwidth of 10:1 or larger. [6] The operating frequency of our designed textile antenna is 1 . 8 GHz to 23.8GHz which exhibits a ratio bandwidh of 13.22:1. Therefore, we can consider this to be a super wide band antenna. Application for the wireless connectivity is increasing rapidly and super-wideband technology is a great choice for wireless connectivity of wearable or on-body communication. In case of wearable antennas it is quite difficult to have a flat antenna surface. Therefore, the designed antenna should be such that, even if the antenna is bent frequently, it should operate properly [7]. This paper presents a novel design of a wearable Super Wide Band (SWB) textile antenna for the material with substrate permittivity,  r = 1.7. It mainly focuses to evaluate the designed antenna's performance under different bending conditions. Here, jeans textile material is used as the antenna substrate and woven copper thread is used as the conductive part of the antenna patch. This paper also demonstrates the effects of a conformal super wide band antenna at eight different angles. Here, the resonance frequency fluctuations due to impedance matching as well as the effects of radiation pattern deformation and efficiency due to antenna bending at different angles are focused. Originality of this work is- the bending consequences on the designed antenna at different angles are uniquely conducted and equally the resultant effects on impedance matching and radiation pattern are investigated.