Electromagnetic band gap (EBG) structure

This project was developed to apply the concept of Electromagnetic Band Gap (EBG) structure in antenna design. The application of EBG structure in the antenna design is important to reduce the mutual coupling which is the critical problem in designing the antenna especially the array antenna. This project consists of two experiments which are circular mushroom-like EBG (cmEBG) structure and microstrip array antenna with EBG structure. For cmEBG structure experiment, the method used was suspended transmission line method while for microstrip array antenna with EBG structure was inset feed microstrip transmission line method. The result of return loss, radiation pattern and gain was obtained by using CST Microwave Studio CAD Software. In cmEBG structure experiment, the EBG structure was designed to work efficiently at 2.4 GHz. A parametric study was performed on cmEBG structure to investigate its characteristics. The parameters involve was radius of cmEBG (rebg), radius via of cmEBG (vebg), substrate thickness (st) or via length (vi) and horizontal and vertical gap. The optimized design of cmEBG structure was applied into microstrip array antenna design to investigate the effect of cmEBG structure to reduce the mutual coupling problem at 2.4GHz. Thus, the forward reflection coefficient, S1,1 and forward transmission coefficient, S2,1 of microstrip array antenna with and without cmEBG structure was observed and analyzed