Tailoring Meta-Liquid Crystal for Larger Tunability

Abstract

Liquid crystals are pivotal innovations in the field of tunable materials. However, in the millimeter wave band, the relatively low tunability of liquid crystal limits its applicability. A design method utilizing metamaterial characteristics to enhance the tunability of a liquid crystal is proposed. This design method is based on two theoretical models. Both models embed metamaterial structures into a liquid crystal, thus tailoring a new tunable material, namely, a meta-liquid crystal. By appropriately designing the metamaterials to meet the corresponding conditions derived in different models, the tunability of the meta-liquid crystal can be higher than that of the original liquid crystal. An application of beam scanning is provided to verify this method. Two beam steerable antenna arrays are designed, fabricated and investigated. The beam scanning range of the meta-liquid crystal antenna array is much wider than that of the original liquid crystal antenna array, which confirms the enhancement of tunability. Consequently, this work fills the research gap in improving the performance of liquid crystals in the millimeter wave band. Simultaneously, a bridge is established between two significant materials: tunable materials and metamaterials. The results imply that the performance of tunable materials can be manipulated by metamaterials.