Antenna feeding network design for 5G massive MIMO Applications

A new design of a microstrip line coupler is proposed. The proposed microstrip line coupler is based on butler matrix, and is dedicated mainly to 5G massive MIMO feeding. The presented design is done using the popular FR4 substrate. A simulated coupler bandwidth that ranges from 2.82 GHz to 4.32 GHz is exploited, with a bandwidth of 1.5 GHz, and a center frequency of 3.6 GHz. The simulation results show that the studied coupler has a high isolation as well as a high return loss of about -30.14 dB at 3.6 GHz center frequency with a good coupling factor. In addition, it achieves an excellent amplitude and phase differences between outputs.