Researches On Wearable Antennas In Wireless Body Area Networks(WBAN)

People's attention to health has been increasing year by year due to the fast-paced lifestyle.Wireless wearable devices which can monitor health indicators of human in real time have gradually become popular.Researching on wearable antennas and analyzing communication links between wearable devices and wearable devices with external devices have become hot topics nowadays.In order to design multi-mode wearable antennas that are more suitable for WBAN applications,this thesis has completed the following works:1.A dual-band on-body/off-body mode reconfigurable antenna is designed.The on-body mode is realized by using circular microstrip patch antenna with shorting pins,ring slot is then etched on the circular patch and the inner part forms the off-body mode.2.A switchable on-body/off-body mode antenna operating at the same frequency is presented.The wearable antenna is based on the structure of circular microstrip patch antenna with shorting pins,and PIN diodes are utilized to switch the operation mode between on-/off-body modes by controlling the states of shorting pins.In order to validate the performance of on-body mode,several typical links are considered and the Friis formula is utilized to analyze the performance of off-body mode.3.For the sake of enrich the application of wearable antennas in WBAN,a wearable antenna which can reconfigure repeater/on-body/off-body modes is proposed.The wearable antenna is based on the structure of rectangular microstrip patch antenna to realize the reconfiguration of on-body/off-body modes,and the performance of repeater mode is realized by using planar inverted-F antenna(PIFA).Finally,the repeater/on-body/off-body modes reconfigurable antenna is realized by combining the bias circuit.4.A triple-port millimeter wave wearable antenna is designed by combining a novel feeding network and substrate integrated waveguide(SIW)cavity-backed slot antenna array.Three ports of the millimeter wave wearable antenna can realize vertical polarization(VP)on-body mode,right hand circular polarization(RHCP)off-body mode and left circular polarization(LHCP)off-body mode,respectively.In this thesis,four wearable antennas are designed by using PIN diodes or feeding network in the background of WBAN,satisfying the communication requirement of WBAN.