Modified Slotted Patch Electromagnetic Band Gap for Antenna Array Application

A modified slotted patch EBG structure has been investigated by measuring the forward transmission coefficient, S21. The thickness and dielectric constant of the substrate, the size and the gap of the elements in EBG structure has been modified and simulated to see the S21 value and followed by a discussion of the design and the evaluation of the structure itself. The simulation process was carried out using Microwave Office 2006 software. The 3 by 3 modified slotted patch EBG structures which has 11 mm x 11 mm elements size was fabricated using inexpensive fire retardant-4 (FR4) board, using wet etching techniques. The stimulated and measured S21 result shows the band gap of the structure, which are found to be between 2.24 GHz and 2.6 GHz at -20 dB. This structure is then incorporated into a 2 by 2 rectangular microstrip antenna array, operating at 2.4. The result shows that the radiation pattern improved with reducing side and back lobe with an extra gain of 1 dB compared with the antenna without the EBG structure.