Super wideband antenna for terahertz and refractive index sensing applications

In this paper, an ultrathin coplanar waveguide (CPW) fed antenna is designed to operate across 3.9->60 THz (%BW ≥ 175.58 %) with bandwidth dimension ratio (BDR) ≥ 2485.59 and peak realized gain of 7.40 dB. During the analysis of the proposed antenna element as a refractive index (RI) based sensor maximum sensitivity(S) ∼3.59 THz/RIU, Figure of merit (FOM) ∼ 58.70 RIU−1, Quality Factor (Q.F) ~188.26, maximum limit of detection (LODmax) ~5.05 RIU, Dynamic Range (DR)>35.00, Detection Accuracy (DA) ∼2.20, and sensor resolution (SR) from 0.18 to 0.93 are achieved. For dual port spatial diversity MIMO configuration having volume of 22.00×56.25×1.60 μm3, super wideband 3.8->60 THz with isolation ≥15 dB is achieved. In dual port pattern diversity MIMO configuration having volume of 22.00×48.07×1.60 μm3, operating band of 3.9->60 THz with ≥20 dB isolation is realized. MIMO diversity parameters are found to have ECC<0.05, CCL<0.40b/s/Hz, and MEG~-3dB. For quad, hexa and deca- ports spatial diversity configurations also super wideband with isolation ≥ 20 dB is achieved. Merits of miniaturized dimensions, wider bandwidth, considerable peak gain, highly sensitive RI-based sensing signify the suitability of proposed structures for variety of terahertz applications, including sensors, industrial 4.0, and other ultra-thin wireless systems.