Graphene based conformal MIMO antenna for future THz wireless applications

Abstract

A graphene-based super wideband (SWB) conformal antenna with dual port MIMO configurations is presented. The antenna element comprises a microstrip line fed annular radiator with a quadrilateral inscribed inside, partial ground plane with a rectangular graphene sheet, used to reduce the lower operating frequency, parallel to it to. The proposed single antenna element is designed on a polyimide substrate with an overall dimension of 600 × 410 × 40 μm³. The antenna operates from 0.74 THz to more than 10 THz (fractional B.W. ≥ 173.83 %), bandwidth dimension ratio (BDR) ≥ 129.79, and peak realized gain of ∼13.67 dB. Graphene material study w.r.t effect of variation in graphene's total conductivity, chemical potential (μ_c) and required biasing voltage (V_bi) is also analyzed. Conformability (compress and tensile strain analysis) is performed on proposed single element antenna from 0° to 50° and approximately no difference in operating band is achieved. Two-port pattern and spatial diversity MIMO configurations with connected ground planes operate over the frequency spectrum of 0.89 THz- >10 THz with an inter-element isolation >27 dB. In pattern diversity MIMO design, fractional B.W. ≥ 169 %, maximum ECC∼ 0.009 and maximum CCL ∼0.14 bit/sec/Hz while in spatial diversity MIMO configuration, isolation range from 27 dB to 77 dB for entire operating band with maximum ECC∼ 0.014 and maximum CCL ∼0.3 bit/sec/Hz are achieved. Also, diversity gain (DG) is ∼10, MEG ∼ -3dB, and TARC < −10dB for all proposed MIMO configurations over the entire operating band. The proposed antenna topologies are suitable for numerous ranges of applications due to their wide operating bandwidth, such as wireless on-chip communications, Tbps wireless LAN (Tera Wi-Fi), telemedicine, remote sensing, Tera IoT, 4.0, 6G cellular system, holographic seminars, and many more.