SRR loaded compact tri-band mimo antenna for wlan/wimax applications

Abstract

A multiband four-element multiple-input-multiple-output (MIMO) antenna configuration is proposed. The antenna consists of split ring resonators (SRRs) along with an inverted L-shaped monopole antenna (ILA) structure on the top of the substrate and a slotted ground plane. The antenna without the SRRs exhibits resonances at 2.4 GHz, 3.66 GHz, and 5.5 GHz with the impedance bandwidth (IBW) of 14.5%, 35.1%, and 9.6%, respectively. With the addition of SRRs, the antenna exhibits additional resonance at 5.1 GHz with improved bandwidth and minimizes the reflections. Consequently, the impedance bandwidth at 5 GHz frequency band gets improved to 17.2%. Overall, the proposed antenna will cover the 2.4 GHz wireless local area network (WLAN) & industrial, scientific, medical (ISM) band, 3.5 GHz worldwide interoperability for microwave access (WiMAX), and 5 GHz WLAN 4G/5G applications. In spite of very compact area (0.094λ20, for the highest operating wavelength) and presence of common ground, the antenna exhibits high inter-element isolation of ≥ −14 dB and S11 ≥ −10 dB. The proposed antenna design is fabricated, tested, and analyzed.