| dc.description.abstract | Device scaling and component-miniaturization are the main drivers of the development
of electronic technology. In time, electronic devices have become smaller
in size and hence, the scaling down of antenna dimensions has come to be not
only an interesting but also substantial areas of research. The gain - bandwidth
product of an antenna is limited by its electrical size, therefore reducing the size of
an antenna narrows the bandwidth or lowers the gain. The work presented in this
thesis contributes to the existing body of research on the structure of electrically
small antennas and complications of its design with regard to the fundamental
limitations.
The large input reactance of electrically small antennas (ESA) are conventionally
matched with passive circuits, however, the matching works at a single frequency
which shrinks the bandwidth. In previous studies, non-Foster impedance
matching which employs active networks of negative inductors and capacitors
to overcome the restrictions of gain-bandwidth theory has been examined. In
this study, the origins and development of Non-Foster impedance matching is
reviewed and its stability issues are discussed. The design and simulation of a
negative impedance converter circuit and together with an electrically small disk
loaded dipole are presented. In this research, the designed matching circuit is
fabricated, measured and its results are analyzed. Additionally, promising future
studies and their possible effects in the antenna field are reviewed. | en_US |
