Analytical Approach of Director Tilting in Nematic Liquid Crystals for Electronically Tunable Devices
Metadatos
Mostrar el registro completo del ítemAutor
Alex Amor, Antonio; Tamayo Domínguez, Adrián; Palomares Caballero, Ángel; Fernández-González, José M.; Padilla De La Torre, Pablo; Valenzuela Valdes, Juan Francisco; Palomares Bautista, Antonio FranciscoEditorial
IEEE
Materia
Liquid crystals Nematic phase Analytical expression Phase shifting Microwaves
Fecha
2019-01-22Referencia bibliográfica
Alex-Amor, A., Tamayo-Domínguez, A., Palomares-Caballero, Á., Fernández-González, J. M., Padilla, P., Valenzuela-Valdés, J., & Palomares, A. (2019). Analytical approach of director tilting in nematic liquid crystals for electronically tunable devices. IEEE Access, 7, 14883-14893.
Patrocinador
This work was supported in part by the Spanish Research and Development National Program under Project TIN2016-75097-P, and in part by the Ministerio de Economía under Project TEC2017-85529-C3-1-R.Resumen
This paper presents an analytical expression that models the tilt angle of directors in a nematic
liquid crystal (LC), depending on its elastic properties, its dielectric anisotropy, and the quasi-static electric
field applied. The analytical solution obtained is fast and easily computable in comparison with numerical
estimations and is of special interest in radiofrequency; for instance, for the LC modeling in full-wave
electromagnetic simulators in the design process of electronically tunable devices, such as microwave phase
shifters or electronically steerable antennas for satellite communications. Subsequently, a comparison is
made between numerical approaches (self-implemented shooting method) and the analytical formulas when
varying the parameters of the LC, being demonstrated its usefulness. The average LC director is then obtained
and used to form the full permittivity tensor that completely characterizes the electrical properties of the
material. Finally, an electromagnetic simulation is carried out to show the capabilities of the LC as a tunable
phase shifter. It is shown that only 5 cm of a commercial 200-mm LC mixture is necessary to achieve 360
of the maximum variable phase shift at the 30-GHz band