Design of an Ultrawideband E-shaped Conformal Antenna for Wireless Capsule Endoscope

Wireless capsule endoscopy (WCE) system has received lots of attention in recent years, mainly due to its noninvasive technology and advantage of being able to travel through the whole digestive tract, which differs from the traditional endoscopes. In order to transmit the high resolution image with high speed up to several Mbps, the WCE system needs to have ultra-wideband (UWB) characteristics. As an important part of WCE system, antenna plays a crucial role in transmitting and receiving data. In this paper, an E-shaped conformal antenna at UWB low band of 3.4 GHz-4.8 GHz is designed and evaluated using Finite Integration Technique (FIT) technique together with human equivalent phantoms. This antenna is conformed to the inner wall of the capsule, leaving embeding space for other electronic components within the capsule. The impedance matching range of -10 dB was obtained 3.34 GHz-7.36 GHz with omni-directional radiation pattern. Moreover, the stability of the designed antenna is verified in the gastrointestinal tract area of the human model, which can satisfy the requirements of the capsule endoscope system. To comply with IEEE safety standards, the maximum input power of the designed antenna is limited to 65.3 mW.