MTM-EBG Loaded Circular Patch Antenna for ISM Band Applications

A dual frequency circular microstrip patch antenna is designed with transmission line metamaterial based electromagnetic bandgap (MTM-EBG) structures in this article. The two frequencies of interest are chosen as 2.4 GHz and 5.75 GHz covering industrial, scientific, and medical (ISM) band applications. The MTM-EBG unit cell is designed with the combination of interdigital capacitance and rectangular apertures. Twelve MTM- EBG unit cells are placed together to form a periodiccircular EBG surface around a low profile small circular microstrip patch resonating at 5.75 GHz. The arrangement is placed in such a way that the overall effective radius of the patch can be manipulated to get the resonances at both the operational frequencies by utilizing the bandgap of the EBG cells.