New approach for chipless and low cost identification tag in the THz frequency domain

In the present paper, we present a new approach for data encoding in the THz frequency domain. We proposed a structure based on a 1D periodic stack of dielectric layers whose thickness is of the order of the wavelength, i.e. in the millimeter range. Such a device exhibits well known forbidden band gap (FBG) behavior when illuminated by an electromagnetic wave. We suggest modifying the periodicity of the stack to create defect levels in the 1^st FBG to encode binary information. The layers are made of low cost dielectric materials such as pure low density polyethylene (LDPE) and a mixture of LDPE with mineral charges like CaCO₃ or TiO₂ as respectively low (L) and high (H) refractive index material. We show that such a device can be used for binary data encoding in the frequency range from 150 to 600 GHz with encoding capacities greater than 10 bits.