Liquid crystal-enabled tunability of Yagi-Uda antenna resonant properties

Abstract

We demonstrate the application of liquid crystals to modulate the resonance properties of Yagi-Uda metamaterial absorbers. The absorbance and reflectance peak frequencies and amplitudes were found to be adjustable by reorienting the liquid crystal, irrespective of the polarization of the incident light. Notably, the lowest resonant frequencies were observed when the liquid crystal was in the homeotropic orientation, whereas a reorientation toward the y -axis showed a significant frequency increase, up to 1 GHz. Incorporating liquid crystals to the Yagi-Uda antenna arrays can also serve as a method for eliminating undesired modes, not associated with the antenna resonance. This can be achieved by taking advantage of the sensitivity differences of these modes to refractive index components. The results presented in this study highlight the potential of liquid crystals to deliver dynamic manipulation and real-time adaptability of Yagi-Uda antennas.