Implanted antenna for WBAN communication

Abstract

As the wireless network needs to high data rate communication in order to satisfy user requirements for services, the network system has been diversified, for example WPAN (Wireless personal area network), WLAN (Wireless personal area network) and WBAN (Wireless Body Area Network) [1]. Especially WBAN system consists of wearable and implanted devices near the human body, and it supports the medical and non-medical (Financial and Entertainment, etc) services. The typical system of WBAN is the wireless capsule endoscope system which operates and supports low-speed communication for digestive apparatus images at MICs (402~405MHz) [2, 3]. This paper proposed the broadband implanted antenna for capsule endoscope at the low frequency (250~310MHz) which has lower transmission loss than that of MICs. The specific measurement system considering the electrical characteristic of body medium is realized and the performance of the proposed antenna is measured. The author confirmed the intercommunication with implanted and wearable antenna. In order to obtain the broadband characteristic for implanted antenna, a variety of broadband techniques are considered in the simulated fluid which has same characteristic as body medium. The proposed antenna has the enough electrical length in the small volume for broadband by transforming the typical spiral. The antenna pattern has non-uniform spacing between the adjacent lines for impedance matching and miniaturization. As it is impossible to control the attitude of capsule endoscope, the implanted antenna needs to radiate omni-directionally. The specific measurement system is realized to measure the performance of antenna accurately. Because there is no reference antenna, the 3-antenna measurement is applied. In addition, the measurement space is too small unlike anechoic chamber system, so the author applied the extrapolation technique to specific measurement system. The intercommunication with implanted and wearable antennas ...