A Micro 4-port THz MIMO antenna for nano communication networks

Abstract

This paper proposes a micro nature inspired UWB 4-port MIMO antenna design with dimensions of 45μm × 45μmăoperating from (2.38–11.18) THz and 130% impedance bandwidth realised on a 2μm thick polyamide substrate. Each radiator is made by superimposing self-similar elliptic structures to create a palmate leaf-like pattern that ensures wideband response. The ground topology is made up of semi-elliptic orthogonal reflectors connected to a center-fed annular circle with rotationally symmetrical parasitic stubs that operate as an isolator, resonator, and neutralizer. The antenna elements are ordered orthogonally with an inter-element distance of d0 = 0.05λ0 (λ0 is the lowest working wavelength at 2.38 THz) and an inter-element port isolation distance of d0 = 0.05λ0. The parasitic stub inclusion increases the lower/higher band 10-dB impedance matching response, and the proposed ground structure has good isolation coefficients (18−22)dB. An equivalent circuit model with R-L-C lumped elements was modelled and simulated to validate. In both indoor and outdoor propagation environments, the MIMO diversity parameters (Envelope channel coefficient (ECC), Total active reflection coefficient (TARC), Diversity gain (DG), Channel capacity loss (CCL), Mean effective gain (MEG), and Multiplexing efficiency) show good characteristics to leverage. The suggested MIMO antenna can be employed for THz band and molecular/nano communication networks owing to its radiation performances (realised gain of > 8 dBi with > 60% radiation efficiency).