A Novel Multi-band EBG Structure Using Nested Square Grooves

A nested rectangle electromagnetic bandgap structure with dual broadband band is designed to enhance the performance of telecom/mobile 5G antennas operating at 3.3GHz and 4.9GHz, which has a short frequency spacing of about 1.6GHz. through loading EBG structure under dipole antenna, directional radiation, low profile and high gain performance have been achieved. The distance between electromagnetic bandgap (EBG) structure and antenna is only 0.067 wavelength, the first band and the second band of EBG are greatly expanded by etching nested square grooves around the EBG (NSGEBG) as compared with traditional etched ring groove EBG (ERGEBG). The bandwidth of the first band of 0.39GHz is twice wider than that of the ring groove of 0.2GHz, the second band has a bandwidth of 0.46GHz, which perfectly solves the problem that the spacing of the two operating frequency is greater than 2GHz.