A characteristic mode analysis-based isolation enhancement for a THz MIMO antenna

Abstract

Abstract The terahertz (THz) frequency range has attracted research interest due to its wide available spectrum and short wavelengths. This work provides a comprehensive analysis of an wideband THz multiple input and multiple output (MIMO) antenna that uses a neutralization line (NL) to reduce inter-element interference. A standard circular patch antenna is modified by reducing the ground plane to create a wideband THz antenna. Furthermore, a four-port THz MIMO antenna is produced by horizontally and vertically replicating the designed THz antenna with a size of 46 × 46 × 2 µm 3 . A hybrid decoupling structure consisting of a transformed ground plane and a rectangular-shaped neutralization line reduces the inevitable mutual coupling between the MIMO elements. The proposed THz MIMO antenna exhibits isolation greater than 22 dB over the operational frequency range of 3.3–11.1 THz. The proposed THz MIMO antenna is analyzed for radiation properties and diversity features, such as ECC < 0.1, DG > 9.5 dB, MEG≤-6 dB, TARC < -10 dB, CCL < 0.2 bps/Hz, and ME < 0 dB. The results validate the effectiveness of the CMA-based isolation enhancement framework within the investigated THz frequency range under full-wave electromagnetic simulation.