Reconfigurable Millimeter-Wave Reflectarray Based on Low-Loss Liquid Crystals
Dayan Pérez-Quintana, Erik Aguirre, Eduardo Olariaga, С. А. Кузнецов, В. И. Лапаник, В. С. Сутормин, V. Ya. Zyryanov, José Antonio Marcotegui, Miguel Beruete
Abstract
This article reports on the development and evaluation of a reconfigurable millimeter-wave reflectarray (RA) based on liquid-crystal (LC) substrate operating in the D-band (105–125 GHz). The RA is composed of a high-impedance surface (HIS) with a meta-array of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$33\times 29$ </tex-math></inline-formula> patches on a 2-mm-thick quartz substrate, separated from the ground plane (GP) by a 40- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -thick LC layer. A novel LC composition with low dielectric losses (< 0.003) and high dielectric anisotropy ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$>$ </tex-math></inline-formula> 1.3) has been developed for operation at millimeter waves. The results demonstrate a reflection phase tunability of 210° and low insertion losses of 2.5 dB. Furthermore, the device was demonstrated as a proof of concept for 1-D beam-steering applications, exhibiting an operational bandwidth of 12 GHz.