Ultra-Wideband MIMO Diversity Antenna System for Future Handsets

A new design of UWB-MIMO antenna system is proposed for future smartphones. The design contains four pairs of compact microstrip-fed slot antennas with dual-polarized function that are placed symmetrically at different edge corners of the smartphone mainboard. Each antenna pair consists of a circular-ring slot radiator fed by two independently semi-arcshaped microstrip feeding lines which can exhibit polarization diversity characteristic. The characteristics of the smartphone antenna are examined using both simulations and measurements and good results are achieved. An impedance bandwidth of 2.5–10.2 GHz with 121% fractional bandwidth (FBW) is achieved for $\mathrm {S}_{11}\leq $-10dB. However, for $\mathrm {S}_{11}\leq $-6dB, this value is more than 130% (2.2–11 GHz). In addition, the calculated diversity performances of the design in terms of ECC and TARC are very low over the entire operation band. Furthermore, sufficient values for the channel capacity and its loss are obtained.