Microwave characteristics of liquid-crystal tunable capacitors

Measurement of Dielectric Anisotropy of Some Liquid Crystals for Microwave Applications

“…For this reason, intensive research has focused on applications of LC in GHz. [6][7][8][9][10][11][12]. This work includes the assessment of selected nematic liquid crystals in terms of dielectric permittivity modulation in 0.01-6 GHz range.…”

Identifying dielectric and resistive electrode losses in high-density capacitors at radio frequencies

“…Tunable technologies based on micro-electro-mechanical-systems (MEMS) [1], [2], varactor diodes [3], liquid crystals [4] or ferroelectrics [5] support the continuous miniaturization of microwave electronics. We optimize ferroelectric capacitors on silicon as a potential key component for microwave frequency agile applications.…”

Geometry-Based Tunability Enhancement of Flexible Thin-Film Varactors

“…State-of-the-art technologies realize tunable capacitors either by MEMS based mechanical changes in geometry [6], by inversion type metaloxide-semiconductor (MOS) stacks [2] or a change in the dielectric constant of the insulating material in metal-insulatormetal stacks, e.g. implemented by ferroelectric [7] or liquid crystal [8] type dielectrics. Regarding the field of flexible electronics, the two latter ones can be realized, but yield tunabilities smaller than 0.3 [7], [8].…”

“…implemented by ferroelectric [7] or liquid crystal [8] type dielectrics. Regarding the field of flexible electronics, the two latter ones can be realized, but yield tunabilities smaller than 0.3 [7], [8]. Here, we present two designs of amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) based thin-film varactors fabricated on free-standing Polyimide foil, which are realized in a metal-oxide-semiconductor-metal stack.…”