| dc.description.abstract | Provision of efficient services to the user anywhere at anytime is being a centre of research
and development in Wireless Personal Area Networks (WPAN) and Wireless Body Area
Networks (WBAN). Antenna is the essential part of WPAN/WBAN applications that
got affected by two major factors: human body presence and nature of the surrounding
environment. The presence of the human body in the proximity of the antenna causes
electromagnetic (EM) reflections from the body surface and absorptions in the lossy body
tissues resulting in antenna detuning, radiation pattern degradations and impedance
mismatch. On the other hand, incident radio waves undergo reflections, difractions and
scattering from the surrounding environment objects including buildings, trees, vehicles
and ground, causing multipath fading.
The thesis gives an overview of the main investigations, results and analyses accomplished
in a study concerning the commercially available Bluetooth and GPS antennas working
in the vicinity of the human body. Detailed numerical modelling process is adopted
followed by measurements for validation. The thesis highlights the role of surface waves
as a potential transmission medium in an on-body Bluetooth wireless communication
link taking into account the effects of antenna-body separations and presence of the
surrounding objects blocking the direct communication path. The thesis also presents
a novel statistical model to evaluate the performance of GPS mobile terminal antennas
in the multipath environment. This model characterises the antenna performance and
identifies the key factors that can be used to enhance it, in a real working environment
outside an anechoic chamber. The study also deals with presence of the human body in
the multipath environment and its effects on the operation of the GPS antennas. | en_US |
