Design and Optimization of Broadband High Impedance Ground Planes (HIGP) for Surface Mount Antennas
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
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Gain and bandwidth metrics of broad-band low-profile antennas severely deteriorate when they are placed conformally onto the conductive skins of air, sea, and ground platforms. This detrimental effect is primarily due to out-of-phase reflections from the conductive body interfering with the antennas self radiation. Furthermore, lateral waves launched by the antenna couple into the thin substrate placed between the antenna and the platform, giving rise to surface waves resulting in significant diffraction from the edges of the substrate. To remedy these two major mechanisms degrading antenna performance, high impedance ground planes HIGP were designed. HIGPs made of a 2-dimensional periodic arrangement of a mushroom structure not only provide perfect-magnetic-conductor PMC-like reflection but also suppress the surface waves within the stop-band of the substrate modes. This study presents new geometrical shape HIGP-antenna designs and optimizations. Dipole antenna, log periodic antenna and finally bow-tie antennas are used in the study. Multi-scale HIGP and antenna designs are introduced in the final part of the thesis.
- Electrical and Electronic Equipment