Low cost high gain triple band mmWave Sierpinski antenna loaded with uniplanar EBG for 5G applications

A triple band mmWave microstrip antenna on low-cost FR4 substrate is proposed in this paper. The triple band is achieved using Sierpinski fractal structure with an optimized ground plane. The resonances observed are at 29.05 GHz, 35.75 GHz and 41 GHz with 10 dB impedance bandwidths of 4 GHz, 2.06 GHz and 2 GHz respectively. These bands fall into the candidate bands for upcoming 5G applications. The proposed unloaded triple band antenna has low gain throughout these bands, hence a uniplanar optimized EBG structure is proposed for gain enhancement across the intended bands of operation. The reflection-phase of various structures of EBG unit cells were characterized to obtain the optimum design. The optimum unit cell was loaded onto the triple band antenna to obtain Peak Gain of 2.37 dBi and 17.37 dBi in the 28 and 38 GHz bands, respectively. The proposed EBG loaded antenna is fabricated and characterized.