الفهرس 
CHAPTER (1) INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Reflectarray antennas find wide applications in terahertz communications. Traditional reflectors suffer from heavy weight, complicated structure, losses, and / or narrow bandwidth. Reflectarray antennas are designed on planner substrates of dielectric materials so it has low profile, light weight, high efficiency, and large bandwidth.
The aim of this thesis is to design different reflect array antennas by using graphene as a patch. Graphene has an excellent electrical and mechanical properties in THz range, so it is used in creating patches of the array.
The design procedure of the reflectarray starts with the selection of the unit cell shape and design its parameters. The reflection phase curve of the unit cell is found. Then the dimensions of the reflect array are found. Twelve different unit cells are suggested and four of them are used to to construct reflectarray antennas for THz application.
The four designed reflectarray antennas are based on circular, octagonal, hexagonal and square unit cell shapes. They are found to be superior to other reflectarrays published in the literature.
Coding metasurfaces are designed to control radiation of electromagnetic waves. Metasurfaces are designed to scatter an incident plane wave into two and four beams.