Tri-Band, Polarization-Independent Reflectarray at Terahertz Frequencies: Design, Fabrication, and Measurement

In this paper, two THz reflectarray surfaces have been designed and fabricated in order to deflect a plane wave with any polarization and with a specific incident angle to three different specific directions each at distinct three frequencies of 0.7, 1.0 and 1.5 THz. The surface is composed of an array of 100 100 cells, each comprised of gold crosses and parasitic dipoles printed on thin grounded high resistivity silicon. Finite-element method (FEM) simulations are in line with the measurement results obtained using THz time-domain spectroscopy (THz TDS) showing the intended deflections for the two fabricated samples each with an arbitrary frequency-vs-deflection angle relationship. In addition, the use of silicon as the substrate paves the way for the integration of reconfigurable technologies which enhances the reflectarray versatility.