Investigation of an Optimal Distance between the Microstrip Patch Antenna and the Surrounding Electromagnetic Bandgap Structure

Microstrip patch antennas are the most common form of printed antennas in antenna community. Besides the advantages of the microstrip patch antennas they have some unwanted features as surface wave excitation. Similarly, electromagnetic bandgap (EBG) structures are drawn major attraction with their interesting features in electromagnetics and antenna community. These structures are periodic in nature that prevent the propagation of unwanted surface waves consequently reduce side-lobe levels and increase front to back (F/B) ratios of the antennas within a particular frequency band. In this study, mushroom like EBG structures are used with a microstrip patch antenna operating at 10 GHz and the influence of the distance between the EBG structures and the antennas radiating edge is studied. By investigating the obtained results from full-wave numerical electromagnetic simulations and comparing the antenna performance parameters like gain, directivity and bandwidth, the optimal distances for placing the EBG structures are concluded.