A Three-Layered Monopole Antenna Design with EBG Structures

Design of a three-layered monopole antenna with four electromagnetic band gap (EBG) structures is proposed in this paper. The EBG structures are positioned in the middle layer of the monopole antenna and next to the microstrip feed line, which not only shows the notch characteristics at 4.68-4.85 GHz, with a decrease in gain from 1.9dB to −3.7dB, but also optimizes the S11 of the antenna at 7.2-7.8 GHz, and achieves a higher gain at 7-8 GHz. This proposed method may be suitable for designing wideband systems that require notch function and for improving antenna gain.