Dielectric resonator reflectarray antenna in Ku-Band

Abstract

Direct broadcasting satellite has become a vital system in satellite communication globally especially for digital broadcasting purposes. Currently, a parabolic antenna is normally used for this application, however the advantages of reflectarray which is flat in shape and possibility for beam steering capability make the reflectarray antenna is one of the interesting topic to be studied. At the current time, many reflectarrays are based on microstrip technology. Nevertheless, at high frequency the conductor loss is high and the antenna efficiency will be reduced. An interesting solution is to use dielectric resonator antennas (DRAs) as the reflectarray elements. In facts, DRA can give low loss and high bandwidth. In this thesis, firstly four different slots with alphabets underneath the rectangular DRA have been investigated as unit-cell for reflectarray. A new structure of rectangular DRA with C-shaped slot unit-cell has been proposed which can give high phase range (321.9o) and low loss (0.3685o). This structure is then being validated experimentally in Ku-Band. Next, the mutual coupling effects between unit-cell in the reflectarray are studied and a simulation technique based on Finite Different Time Domain (FDTD) is proposed. By doing so, this simulation technique is most suitable to predict the actual reflectarray radiation pattern. Finally, the reflectarray antenna composed of 24 x 24 unit-cells based on DRA with C-shaped slot is proposed at 12 GHz.