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149495 https://hdl.handle.net/2286/R.I.8791 http://rightsstatements.org/vocab/InC/1.0/ All Rights Reserved 2010 v, 39 p. : ill. (some col.) Masters Thesis Academic theses Text eng Bae, Kyong Hwa Aberle, James T. Balanis, Constantine Pan, George Arizona State University Partial requirement for: M.S., Arizona State University, 2010 Includes bibliographical references (p. 35) Field of study: Electrical engineering Antennas are required now to be compact and mobile. Traditional horizontally polarized antennas are placed in a quarter wave distance from a ground plane making the antenna system quite bulky. High impedance surfaces are proposed for an antenna ground in close proximity. A new method to achieve a high impedance surface is suggested using a metamaterial comprising an infinite periodic array of conducting loops each of which is loaded with a non-Foster element. The non-Foster element cancels the loop's inductance resulting in a material with high effective permeability. Using this material as a spacer layer, it is possible to achieve a high impedance surface over a broad bandwidth. The proposed structure is different from Sievenpiper's high impedance surface because it has no need for a capacitive layer. As a result, however, it does not suppress the propagation of surface wave modes. The proposed structure is compared to another structure with frequency selective surface loaded with a non-Foster element on a simple spacer layer. In particular, the sensitivity of each structure to component tolerances is considered. The proposed structure shows a high impedance surface over broadband frequency but is much more sensitive than the frequency selective surface structure. Electromagnetism Antenna ground Artificial Magnetic Conductor Artificial Magnetic Material High impedance surface Non-Foster elements Electromagnetic fields Antennas (Electronics) High impedance surface using a loop with negative impedance elements