Compact four‐element SRR‐loaded dual‐band MIMO antenna for WLAN/WiMAX/WiFi/4G‐LTE and 5G applications

A four‐element dual‐band MIMO configuration consisting of split‐ring resonator (SRR)‐loaded inverted L‐monopole antenna elements is realised. In the proposed antenna, the lower‐frequency mode of the unloaded MIMO configuration merges with one SRR‐induced antenna resonance. This leads to antenna operation around 2.93 GHz with wide impedance bandwidth (IBW) of 35.21%, encompassing the lower WLAN, worldwide interoperability for microwave access, wireless fidelity, fourth generation (4G)‐long‐term evolution and sub‐6 GHz 5G bands. Furthermore, due to SRR loading, the proposed MIMO antenna exhibits a resonance at 5.68 GHz (IBW 6.86%), covering the upper WLAN band. Minimum inter‐element isolation of 14 dB is achieved, in spite of the compact total area ( , λ 0 = highest operating wavelength) and the presence of inter‐connected ground plane. Both the working bands exhibit directional radiation patterns with average gain . Experiments on the fabricated antenna prototype confirm that the simulated and measured S ‐parameters, radiation patterns (envelope‐correlation coefficient, channel capacity loss and total active reflection coefficient) are in good agreement.