Novel Structures and Materials for Broadband Antennas
Presented in this thesis are advancements made in the fields of broadband antennas, reconfigurable antennas and emerging materials in applied electromagnetics. Firstly, the investigation of a millimeter-wave log-periodic toothed antenna (LPTA) is shown. The design features a novel integrated planar feed structure which provides an extreme broadband input match. Simulation is carried out using a finite-element code (Ansys HFSS) to demonstrate operation from 22.8 GHz to 44.0 GHz with a peak realized gain of 7.48 dBi. Secondly, the investigation of an aperture-coupled liquid metal dipole antenna is presented to demonstrate continuous frequency reconfigurability over a 21% tuning bandwidth. A novel aperture-coupling feed structure with reduced back radiation is explored as a means to excite the liquid metal dipoles without requiring physical contact. A prototype is fabricated and measured where an input match of S11<-13 dB and peak gain of 3.99 +/- 0.51 dBi is observed over the tunable range. Thirdly, the broadband dielectric spectroscopy of emerging novel microelectronic materials is presented. Materials studied are those seeing use in microfluidic electronics, wearable electronics, and 3D printed electromagnetic structures. Complex permittivity is measured using commercial coaxial probes and novel analytic Cole-Cole models are produced through a non-linear least squares fitting routine on experimental data.
URI for this recordhttp://hdl.handle.net/1974/28615
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