Terahertz Metamaterial Absorber for Biomedical Sensing and EMI/EMC Applications Using Concentric Resonators

Abstract

A terahertz (THz) metamaterial absorber has been proposed in this paper for biomedical sensing and electromagnetic interference and electromagnetic compatibility (EMI/EMC) applications. The design is capable of sensing the alterations in the refractive index of the encompassing medium. The proposed design consists of three concentric Circular Ring Resonators (CRRs) and three more rhombus-shaped ring resonators made out of gold over a gallium arsenide substrate. It achieves a near-to-perfect absorption of 99.92% at 2.53 THz resonance frequency. Parametric analysis has been carried out on the design parameters to justify their choice. The design has also been examined under various polarization angles, and it is found that the absorber is insensitive to polarization. The proposed sensor possesses a high Quality factor (Q-factor) of 42.16. The refractive index was altered within the range of 1.35 to 1.40 because many biomedical samples are centered around this range. Further, the sensitivity of the absorber has been computed to be 1000 GHz/RIU, along with a Figure of Merit (FoM) of 16.67 that makes it a good refractive index sensor that could be used for biomedical applications. The absorber can also be used for other applications, such as imaging, EMI shielding, EMC, and THz communications.