This thesis presents a number of microwave devices and antennas that maintain
high operational efficiency and are compact in size at the same time. One goal
of this thesis is to address several miniaturization challenges of antennas and
microwave components by using the theoretical principles of metamaterials,
Metasurface coupling resonators and stacked radiators, in combination with the
elementary antenna and transmission line theory. While innovating novel
solutions, standards and specifications of next generation wireless and
bio-medical applications were considered to ensure advancement in the
respective scientific fields. Compact reconfigurable phase-shifter and a
microwave cross-over based on negative-refractive-index transmission-line
(NRI-TL) materialist unit cells is presented. A Metasurface based wearable
sensor architecture is proposed, containing an electromagnetic band-gap (EBG)
structure backed monopole antenna for off-body communication and a fork shaped
antenna for efficient radiation towards the human body. A fully parametrized
solution for an implantable antenna is proposed using metallic coated stacked
substrate layers. Challenges and possible solutions for off-body, on-body,
through-body and across-body communication have been investigated with an aid
of computationally extensive simulations and experimental verification. Next,
miniaturization and implementation of a UWB antenna along with an analytical
model to predict the resonance is presented. Lastly, several miniaturized
rectifiers designed specifically for efficient wireless power transfer are
proposed, experimentally verified, and discussed. The study answered several
research questions of applied electromagnetic in the field of bio-medicine and
wireless communication.Comment: A thesis submitted for the degree of Ph
