Dual-port 28 GHz pattern reconfigurable quadruple parasitic IFA design for MIMO 5G mobile terminal

In this paper, a 28 GHz pattern reconfigurable Quadruple Parasitic Inverted F Antenna (QPIFA) for Multiple Input Multiple Output (MIMO) Fifth Generation (5G) mobile terminal is presented. A driven cross patch antenna surrounded by four parasitic IFA elements were used to perform the pattern reconfiguration. Metal shorting PIN diodes are used to connect the driven cross patch antenna and the IFA parasitic element to change the direction of the radiation beams. Four types of combination between the driven cross patch antenna and the IFA parasitic element produces eight different beam directions at port 1 and port 2. Maximum realized gain of 9.13 dB, 9.81 dB, 8.65 dB and 7.11dB are achieved. The proposed MIMO structure resonates at 28 GHz while achieving reflection coefficient of less than -20dB. Besides that, a high isolation between 2 QPIFAs reduces the mutual coupling to result in an Envelope Correlation Coefficient (ECC) of less than 0.01. Along with its pattern reconfigurable ability and low ECC, the proposed MIMO antenna is deemed suitable for future 5G mobile terminal application.