Compact Four-Port MIMO Antenna System at 3.5 GHz

This work proposed a compact multiple-input multiple-output (MIMO) antenna system having four antennas each fed by coplanar waveguide (CPW) operating for 3.5GHz band (3400 similar to 3600) MHz.The proposed MIMO antenna system is realized with two groups of printed Inverted L-monopole of size 5 x 4 mm(2) placed orthogonally to each other to attain the diversity capability of polarization and pattern at the edge of non-ground portion of size 15 x 15 mm(2) of mobile handset.The proposed MIMO antenna system consists of four monopole inverted L shape radiator each with parasitic shorted stripe extending from the ground plane having same dimensions.The parasitic inverted L shorted striped served as tuning element by reducing the resonating frequency of the monopole radiator and improving the impedance matching.The mutual coupling between the closely packed antennas is addressed by the neutralization line by feeding anti-phase current to the neighbor antenna.The simulation result showed that that the impedance bandwidth at S-11 <= -10 dB is 200 MHz enough for 5G network communication channel.The diversity parameters of interest are envelop correlation coefficient and mean effective gain are also calculated.