715 Taimoor Khan and Shaban Barbhuiya International Journal of Engineering Technology Science and Research IJETSR www.ijetsr.com ISSN 2394 – 3386 Volume 4, Issue 5 May 2017 Study of Different Slotted UWB Antennas for Capsule Endoscopy Applications Taimoor Khan and Shaban Barbhuiya Department of Electronics and Communication Engineering, National Institute of Technology Silchar, India Abstract- In recent years, Wireless communications have played an important role in the advancement of medical treatment and diagnosis. Wireless capsule endoscopy (WCE) is one such example. It is a non-invasive method used extensively in the diagnosis of gastrointestinal tract diseases. However, its application is critically limited by various factors such as low data transmission rates, capsule size and lack of antenna propagation efficiency. Antennas play a major role in mitigating most of these issues. Hence, the design of a WCE antenna is explored in this paper. Three miniaturized UWB antennas are designed and optimized for WCE by exploring various optimization techniques, such as employing dielectric substrates with high permittivity and the lengthening of the current flow patch on the patch surface. The performanceis investigated by placing the antennas inside a homogeneous single layered phantom model. The antennas are also tested for specific absorption rate (SAR,) for compliance with the IEEE C95.1-1999 recommended health standards. 1. Introduction Endoscopy is the traditional method for detecting abnormalities in the human gastrointestinal (GI) tractand it is used in the diagnosis and detection of a variety of diseases such as colon cancer, gastrointestinal bleeding, gastro-paresis, Crohn‟s disease, etc. The primary requirement is a thin and long flexible tube, which on insertion through the oral cavity; gives real time images of the stomach, colon and rectum in high definition. This accounts for about 4 feet of the gastrointestinal tract. The remaining 20 feet GI tract remains undiagnosed. Hence, posing as a major disadvantage to the conventional method of endoscopy. This led to the development of WCE (wireless capsule endoscopy) with the swallowable-capsule concept first appearing 1957, when R.S. Mackay developed an endo radiosonde (ERS) based on a tunable Colpitts oscillator for measuring pressure within the GI tract for diagnosis [1]. It overcame the conventional drawbacks and allowed for a cable free visualization of the GI tract, including the small and large intestines [2]. Generally endoscope capsule consists of a wireless IC transceiver, LEDs, batteries, camera sensors, and an antenna. Due to limitations in capacity, the antenna is required to be physically diminutive, which leads to a heightened challenge for it to be matched to IC transceiver at specific frequencies [3-5]. Furthermore, the human body acts like a lossy dielectric material absorbing a number of waves and attenuating the receiving signal power, thus having a strong negative influence on microwave propagation. There are three major frequency bands; MICS (medical implant communication service), ISM (industrial, scientific and medical), and UWB (ultra-wideband) that are taken into consideration in the development of antennas for endoscopy [6-10, 17]. The MICS band allocated by the FCC basis in 1999, specifies the use of a frequency between 402-405 MHz for medical implant communication allowing for a bi-directional communication channel for electronic implants. In order to reduce the interference risk, the max power transmission is limited to 25 μW or -16 dBm. The (902–928 MHz, 2.40–2.48 GHz, 5.725–5.875 GHz) bands, constitute the ISM band. UWB signals are signals having a 0.2 fractional bandwidth or larger and a minimum bandwidth of 500 MHz. The UWB signals operate in the 3.1-10 GHz frequency band and an effective