Gain Improvement of Microstrip Patch Antenna using Octagonal-Loop Metasurface Superstrate and Octagonal-Shaped EBG Structure

This paper presents gain improvement of microstrip patch antenna using octagonal-loop metasurface superstrate and octagonal-shaped electromagnetic band gap (EBG) structure for 2.4 GHz band application. An FR-4 substrate with 150%150 mm² with a dielectric constant of 4.3 was used in the antenna design. The metasurface worked as superstrate layer and the radiating patch was designed in fractal shaped. The EBG structure was mounted onto the antenna substrate around the radiating patch to reduce the antenna profile and suppress the surface wave. The superstrate suspends above the radiating patch at the distance of 7. 25mm, to improve the directivity. The measured results of the microstrip antenna with octagonal-loop metasurface superstrate and octagonal-shaped EBG structure have the reflection coefficient with less than -10 dB from 2.38 to 2.52 GHz. The antenna gain is 10.34 dBi at 2.45 GHz.