THz-Ready, Future-Proof: A Multi-Band, Low-Coupling MIMO Antenna for Hyperconnected 6G Networks

This research proposes a compact MIMO antenna system with a dual-port mechanism, utilizing a three-element array specifically engineered to operate within the terahertz frequency band for 6G wireless platforms. Designed on a Quartz (Lossy) substrate with dimensions of 71×72μm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, the design incorporates copper patches (16×12μm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>) excited via 10×2μm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> microstrip feedlines. To support multiband performance, the patch includes narrow insets, overlapping square slots forming an octagon, six rectangular corner slots, and two quarter-circular edge cuts to optimize surface current and bandwidth. The elements are arranged in a tri-arm configuration with 120° separation to ensure symmetrical radiation. Simulations reveal resonant frequencies at 4.038, 6.6, 9.722, and 11.96 THz with return losses between –28 dB and –38.72 dB and directional gains from 5.49 to 8.62 dBi. The antenna maintains linear polarization and near-ideal impedance matching (VSWR ≈1.02). The MIMO configuration demonstrates excellent isolation, showing an excellent value of 2.21×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−7</sup> as ECC and under 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−6</sup> bps/Hz as CCL. These results highlight the design’s suitability for compact, high-performance THz MIMO systems targeting future high-speed communication and sensing applications.