Compact Multiband Reconfigurable MIMO Antenna for Sub- 6GHz 5G Mobile Terminal

In this paper the design of a multiband multiple-input multiple-output (MIMO) antenna with compound reconfiguration capability in the 5G sub-6 GHz band is presented. Frequency and radiation pattern reconfiguration are enabled on the antenna consisting of two planar inverted-F antenna (PIFA) elements using PIN diodes and DC biasing circuits. This results in reconfigurability in multiple bands ranging from 0.8 GHz to 6 GHz for GSM UMTS LTE and 5G-NR bands. At the same time reflection coefficients of less than -6 dB and high isolation of at least -10 dB between ports ensures satisfactory MIMO diversity performance. Within the operating bands total efficiencies of between 46.2% and 74.5% is achieved with less than 0.3 of envelope correlation coefficient. This enables a channel capacity of 9.86 to 10.5 bit/s/Hz. Simulated antenna performance parameters agreed well with measurements and potentially enables reliable and consistent data throughput for 5G mobile terminals.