VO₂ based Ultra-Reconfigurable Ka-Band Reflectarrays for Next-Generation Communication and Radar Systems

A Review of Phase-Change Materials and Their Potential for Reconfigurable Intelligent Surfaces

“…This transition has also been attained using static electric fields [83,84]. Due to the changes in resistivity and permittivity brought about by the transition, VO 2 is an attractive material for applications in switching, optics, thermal diodes, antennas, waveguides, and resonators [79,82,[85][86][87][88][89][90]. Vanadium dioxide (VO2) is the most studied of the many stoichiometric varieties of vanadium oxides due to its attractive phase transition characteristics [77].…”

“…This transition has also been attained using static electric fields [83,84]. Due to the changes in resistivity and permittivity brought about by the transition, VO2 is an attractive material for applications in switching, optics, thermal diodes, antennas, waveguides, and resonators [79,82,[85][86][87][88][89][90]. By taking advantage of this transition and based on their previous work [91,92], Matos et al recently proposed a VO2-based platform that used a VO2 film on a heating matrix to create desired metallic patterns in real-time, very much like generating images on an LCD screen, and used it as a reconfigurable surface to modulate and steer incident EM waves within the 5G spectrum (Figure 3) [1][2][3]93].…”

“…The platform could effectively manipulate the phase, amplitude, frequency, and polarization to control the wavefront. By taking advantage of this transition and based on their previous work [91,92], Matos et al recently proposed a VO 2 -based platform that used a VO 2 film on a heating matrix to create desired metallic patterns in real-time, very much like generating images on an LCD screen, and used it as a reconfigurable surface to modulate and steer incident EM waves within the 5G spectrum (Figure 3) [1][2][3]93]. The platform could reach VO 2 MIT temperatures within 12 ms and revert to its insulating state within about one second.…”

“…This variability in volatility is an important consideration when working with PCMs, and researchers are exploring new ways to leverage this unique property to create more dynamic and tunable materials. Examples of volatile PCMs that have been highly studied at the time of this review are vanadium oxides [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ], titanium oxides [ 10 , 11 , 12 , 13 ], iron oxide (Fe 3 O 4 ) [ 14 , 15 , 16 ], lanthanum cobaltite (LaCoO 3 ) [ 17 , 18 ], niobium dioxide (NbO 2 ) [ 19 , 20 ], and rare-earth nickelates ( R NiO 3 ) [ 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Chalcogenides (Ge 2 Sb 2 Te 5 /Ge 2 Sb 2 Se 4 Te, Sb 2 Se 3 , Sb 2 S 3 ) [ 28 , 29 , 30 , 31 , 32 , 33 ] are among the most studied non-volatile PCMs in the recent literature.…”