A metamaterial-based superstrate inspired circularly polarised MIMO antenna with enhanced gain and bandwidth

This article describes the development and implementation of a circularly polarised multi-input–multi-output (MIMO) antenna that utilizes a metamaterial-based superstrate for improved gain and bandwidth for WLAN applications. The proposed antenna consists of multiple layers including ground plane, substrate, driven patch, airgap, superstrate, and metamaterial. The superstrate consisting of a novel metamaterial array structure is placed above the MIMO antenna with an air gap to enhance its performance. The proposed MIMO antenna is realized using a 1.6 mm thick FR4 for both substrate and superstrate. The driven patches are fed by a single input hybrid coupler (HC) to generate Right Hand Circular polarisation (RHCP). The overall size of the proposed antenna is 0.8 × 1.6 × 0.065 λ0 3 , which is fabricated and tested. The measured results shows that the − 10 dB impedance bandwidth and 3 dB axial ratio bandwidth of the proposed antenna are 16% (2.3–2.7 GHz) and 5% (2.35–2.47 GHz) respectively. The antenna also demonstrates a peak gain of 7.5 dBic and isolation of < 25 dB across the operating frequency range. The radiation patterns are stable with cross polarisation level of <−15 dB. The integration of air suspended superstrate-based metamaterial improved the antenna gain by approximately 4 dBic and impedance bandwidth by 14%. Additionally, the analysis of MIMO performance metrics, demonstrates favourable characteristics suitable for MIMO applications.Kindly check and confirm that the corresponding author is correctly identified.Correct Please check and confirm the author names and initials are correct. Also, kindly confirm the details in the metadata are correct.Second authors first name spelling is incorrect, it's Imaculate not Immaculate, I have corrected it