An integrated MIMO filtenna with wide band-narrow band functionality

Abstract

In this literature an integrated multiple-input-multiple-output (MIMO) filtenna for both Wideband (WB)-Narrowband (NB) functionality is investigated. The approach to the design involves a two element, dual mode MIMO antenna system. In wideband mode two identical circular radiators are used while a pair of rectangular split ring resonator (RSRR) based band pass filters integrated in to the WB antennas are used in narrowband mode. The ground plane is extended in the shape of T shaped stub for the shake of isolation improvement between the ports. All the scattering parameters (S11/S22, S12/S21) of the fabricated antenna prototype are verified in both simulation and measurement for the determination of better antenna performance. Here, a wide impedance bandwidth of 1.2–6 GHz is achieved during wideband mode of operation whereas a frequency response of 3.3–4.0 GHz is found in narrowband mode with isolation in both the cases less than −25 dB and −30 dB respectively. Moreover the performance parameters of MIMO antenna system such as envelope correlation coefficient (ECC), diversity gain (DG) and mean effective gain (MEG) are also evaluated using S matrix to strengthen the design concept.