An Ultrathin Graphite‐Based Absorber for Wearable Applications

ABSTRACT

In this paper, a low‐cost, flexible, ultrathin absorber comprising a simple square patch‐shaped frequency selective surface (FSS) is proposed for wearable applications. The FSS‐based absorbing structure contains a periodic graphite patch pattern placed on a thin paper substrate and backed with a copper foil‐based ground plane. The dimension and periodicity of the unit cell are 0.31 and 0.36, respectively, whereas the thickness of the absorber is approximately , where is the wavelength of free space at 10 GHz. The characteristics of the FSS absorber are optimised in terms of unit‐cell periodicity and dielectric substrate height using a full‐wave high‐frequency structure simulator (HFSS) software. The effects of the parameters are also examined using an equivalent circuit approach. The proposed absorber shows insensitivity towards the angle of incidence and the angle of polarisation. Finally, a prototype model is fabricated, measured and validated with simulation results. Good agreement is observed between the simulated and experimental models. The proposed absorber finds application in the fields of wearable electronics, medical applications and automotive applications for the effective mitigation of the EMI.