Reconfigurable Millimeter-Wave Reflectarray Based on Low-Loss Liquid Crystals

• Published in: IEEE transactions on antennas and propagation 2024-01, Vol.72 (1), p.531-541
• Main Authors: Perez-Quintana, Dayan, Aguirre, Erik, Olariaga, Eduardo, Kuznetsov, Sergei A., Lapanik, Valeri I., Sutormin, Vitaly S., Zyryanov, Victor Ya, Marcotegui, Jose A., Beruete, Miguel
• Format: Article
• Language: English
• Subjects: Bandwidth; Beam steering; D-band; Dielectric loss; Ground plane; High impedance; high-impedance surfaces (HISs); Impedance; Liquid crystals; liquid crystals (LCs); Microwave antennas; Millimeter wave technology; Millimeter waves; Permittivity; reconfigurable reflectarray (RA); Reconfiguration; Substrates; Surface impedance
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2023.3329666

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 33\times 29 patches on a 2-mm-thick quartz substrate, separated from the ground plane (GP) by a 40- \mu \text{m} -thick LC layer. A novel LC composition with low dielectric losses (< 0.003) and high dielectric anisotropy ( > 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.