Design and performance analysis of a DNG metamaterial-enhanced underwater MIMO antenna array for reliable underwater communication

Abstract

This paper presents the design and performance analysis of a novel 2 × 1 MIMO (multiple-input multiple-output) antenna array for reliable communication across multiple frequency bands in surface and submerged environments. The antenna incorporates double negative metamaterials(DNG) in the superstrate to enhance isolation, improve gain, and optimize efficiency. Operating at 1.31-1.37 GHz (L-band), 1.88-1.95 GHz, 2.2-2.32 GHz, 2.63-2.69 GHz (S-band) and 2.82-2.95 GHz (S-Band), it demonstrates strong multiband performance. Performance metrics such as return loss, VSWR, total active reflection coefficient (TARC), envelope correlation coefficient (ECC), and directivity are evaluated through simulations and experiments. The antenna achieves a maximum gain of 12.27 dBi and a TARC value of -22.32 dB at 2.25 GHz, with minimal mismatch loss and high efficiency of 81.3%, even when tested under dynamic underwater conditions. Electromagnetic analysis, including E-field distributions and surface current density plots, highlights the role of the DNG superstrate in wave manipulation and isolation enhancement. The proposed design demonstrates significant performance improvements, positioning it as a promising solution for underwater communication in marine exploration, underwater navigation, and remote sensing applications.