ASU Electronic Theses and Dissertations
- 2 English
Articially engineered two-dimensional materials, which are widely known as metasurfaces, are employed as ground planes in various antenna applications. Due to their nature to exhibit desirable electromagnetic behavior, they are also used to design waveguiding structures, absorbers, frequency selective surfaces, angular-independent surfaces, etc. Metasurfaces usually consist of electrically small conductive planar patches arranged in a periodic array on a dielectric covered ground plane. Holographic Articial Impedance Surfaces (HAISs) are one such metasurfaces that are capable of forming a pencil beam in a desired direction, when excited with surface waves. HAISs are inhomogeneous surfaces that are designed by modulating its surface …
- Pandi, Sivaseetharaman, Balanis, Constantine A, Palais, Joseph, et al.
- Created Date
Multiport antennas offer greater design flexibility than traditional one-port designs. An antenna array is a special case of a multiport antenna. If the antenna's inter-element spacing is electrically small, the antenna is capable of achieving superdirectivity. Superdirective antenna arrays are known to be narrow band and have low radiation resistance which leads to low radiation efficiency and high VSWR. However, by increasing the self-impedance of the antenna elements, the radiation resistance is increased but the bandwidth remains narrow. A design methodology is developed using the ability to superimpose electric fields and multi-objective optimization to design antenna feed networks. While the …
- Arceo, Diana, Balanis, Constantine A, Aberle, James, et al.
- Created Date