Study Of Ultra-wideband Antennas And Their Applications For Body Area Network

As rapid growth in wireless physiological sensors, microelectronics and wirelesscommunications, body area networks (BAN) attract more attention from research community.In addition, body area network systems have wide potential for several applications, such astelemedicine, healthcare service, aiding people with disabilities, military applications, sportsand entertainment. The advantage of low emission power and high data rate makesultra-wideband technology a promising candidate for body area networks. Antennas play acritical role in wireless body area network systems because they can influence the complexityof the receiver and transmitter design. This dissertation was supported by the National NaturalScience Foundation of China (60802004), the Guangdong Province Natural ScienceFoundation (9151064101000090) and the Fundamental Research Funds for the CentralUniversities (2009ZM0114). Two ultra-wideband antennas for body area networks areproposed and studied in this dissertation.Firstly, we study a miniascape-like triple-band monopole antenna for body area networkapplications. This antenna used coplanar waveguide feeding transmission line and flexiblesubstrate which make the antenna conform to human body. With a miniascape-like stripcomposed of an S-shaped strip, a U-shaped strip and an i-shaped strip, three operating bandscovering3.1～3.3,4.2～4.9and6～10.6GHz are obtained, which make it coexistence withother wireless communication systems, such as the wireless local area network, worldwideinteroperability for microwave access system and C-band satellite communication system.Then, a compact planar inverted-F antenna (PIFA) with a simple feed structure in lowerultra-wideband (3.1～4.9GHz) was researched for body area network applications. A taperedpatch and a folded ground plane are employed to improve the narrow bandwidthcharacteristics of traditional PIFA, and3.1～4.6GHz in free space and3.4～4.6GHz on thebody are achieved, respectively. The feed port lies in the air gap between feeding plate andground plane, thus avoiding drilling a hole in the ground plane as other PIFAs.