Design and Experimental Validation of Liquid Crystal-Based Reconfigurable Reflectarray Elements With Improved Bandwidth in F-Band

Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: A Review

“…This issue is especially relevant for RRAs and RALs, whose space-feeding is essential for reducing loss in feeding of the array element as frequency increases. In this context recently liquid crystal (LC) technology has been considered for sub-millimeter-wave frequencies [46]. It has been proposed to address upper terahertz or even infrared frequencies using graphene [35] [47].…”

Liquid crystal based beam scanning reflectarrays and their potential in SATCOM antennas

“…In many cases, the latter led to the generation of very large phase errors across the antenna aperture. More recent investigations described innovative work to overcome these limitations by including several coplanar resonators [4], and by introducing accurate modeling of the LC which enabled the required voltages to be obtained in conjunction with a much reduced phase error [5]. These improved design procedures were used to design an antenna and demonstrate beam scanning in one plane (linear polarization) at 100 GHz [6].…”

“…PNLCs have been demonstrated to be capable of reducing the switching times several orders of magnitude for arbitrary thicknesses in optics [10], and therefore this approach opens the possibility of developing LC reflectarrays at frequencies below 60 GHz. Note that the use of the reflectarray cells such as those reported in [4] implies a thicknesses of 200 µm is required at SATCOM frequencies. As was noted above, investigations to create new cell architectures are necessary to improve in part some of the most important features of the antenna.…”

“…As an example, Fig. 4 shows preliminary computed results of amplitude and phase of the reflection coefficient versus frequency for several permittivity tensors [5] of a multi-resonant cell (size P x =5 mm and P y =4.4 mm) composed of five unequal length dipoles, that operates in Ka-band and uses commercially available LC GT3-23001 (used at 100 GHz in [4]- [7]). A phase range of 600º is achieved within a bandwidth of 10 % that covers the uplink band of SATCOM (from 27.5 GHz to 31 GHz).…”

“…The required phase agility is obtained by exploiting the property of the liquid crystals to change its permittivity by the application of an AC voltage [1]- [4]. This property is exhibited over a wide range of frequencies, spanning AC to optical wavelengths.…”