摘要： In this paper, a multiband pattern-reconfigurable Planar Inverted-F Antenna (PIFA) for Fifth Generation (5G) Multiple Input Multiple Output (MIMO) mobile terminal is presented. A driven cross patch antenna surrounded by four PIFA elements are combined to form a Cross Patch Quadruple PIFA (CPQPIFA) to produce pattern reconfiguration. The direction of the radiation beam changes when the four metal shorting PIN diodes placed in between the driven cross patch antenna and the PIFA element are initiated separately. Activation of these four PIN diodes produces eight different beam directions at port 1 and port 2. The proposed CPQPIFA design is very versatile as it resonates at three frequency bands ranging from 22 GHz to 30 GHz while achieving reflection coefficient of less than -15dB. Besides that, a high isolation between two CPQPIFAs reduces the mutual coupling to result in an Envelope Correlation Coefficient (ECC) of less than 0.03. Along with its advantage in achieving stable pattern reconfiguration and low ECC, the proposed MIMO antenna is deemed suitable for future 5G mobile terminal application.