Electro Chromic-Based Unit Cell for Millimeter-Wave Reconfigurable Reflectarrays

In this paper, the feasibility of exploiting the dielectric tunability of a novel tuneable material, namely Electro Chromic (EC) material, to construct a reflectarray unit cell is demonstrated for the first time. In this regard, the design of an EC-based reflectarray unit cell which provides electronic control of the reflection phase at millimeter wave frequencies is presented. The unit cell is an aperture-coupled microstrip patch which exhibits a maximum reflection phase shift of about Δϕ = 133° at the center frequency of fc = 299.7 GHz.