ELECTRONICAL LY RECONFIGURABLE FS S - INSPIRED TRANSMITARRAY FOR TWO DIMENS IONAL BEAMSTEERING FOR 5G ANDRADAR APPL ICATIONS AT 2 8 GHZ

In this dissertation, the author’s work on a 28 GHz transmitarray capable of antenna beamsteering for various wireless applications, is presented. Such device allows for the adjustment of the radiation pattern of an antenna by changing its main lobe direction, without the need of any mechanical means. A unit-cell based on a square-slot Frequency Selective Surface (FSS) is designed, simulated and optimised through several full-wave simulations, using an electromagnetic solver (CST MWS). Subsequently, the unit-cell was extended to a 10x10 array configuration in order to enable Two-dimensional (2D) beamsteering. This work yielded the fabrication of a prototype composed of four passive transmitarray lens, which were experimentally tested and characterised. Finally, a novel unit-cell based on a double square-slot intended aiming at active beamsteering was also studied and optimised in simulation environment. From this work, it was demonstrated that transmitarray can be seen as feasible alternative to many traditional beamsteering techniques, such as phased antenna arrays, while reducing the RF burden of the overall system using only a single radiation source. This fact, allied with it’s ease of integration, reduced cost and low-profile characteristics make transmitarrays a desirable solution for 5G and RADAR applications, among others