D-Band Absorber Comprising Tantalum Nitride-Based Resistively-Loaded High Impedance Surfaces

This paper proposes a D-band absorber that employs periodic resistive surface made of Tantalum Nitride $(Ta_{2}N)$ deposited on a gold-backed alumina dielectric substrate. The top resistive surface consists of square loop-based unit cells and demonstrates an absorption rate of over 90% across the frequency range from 100 GHz to 166 GHz. The performance of the designed absorber is evaluated through a full-wave simulation method and has been verified using an equivalent circuit model approach. The proposed absorber could be useful in the sub-THz band for various applications, including enhancing MIMO antenna isolation, reducing Electromagnetic Interference (EMI), and integration into other microwave circuits.