Pattern-Reconfigurable Mobile Terminal Antenna System for MIMO and Link Stabilization in LTE

In this paper, a pattern reconfigurable mobile phone antenna system for enhanced data rates in the LTE communication scheme is proposed. The three driven antennas are designed with a resonant frequency of 2.6 GHz (Band VII). Passive elements are utilized in the design in order to change the radiation pattern direction of the proposed antennas. The designed antennas are primarily made to obtain pattern reconfigurability in data mode, where the phone is held either vertically with one hand or horizontally with two hands. Seven different radiation pattern directions are achieved with the proposed antenna setup. With the use of RF switches and tuning devices, such as a programmable array of capacitors (PACs), this architecture can be implemented in handheld terminals. In this work, prototypes with fixed architecture and different lengths of passive elements are presented. Finally, the MIMO performance of the system is investigated by calculating the envelope correlation coefficients, which are under 0.25 in the band of interest.