Multifunctional device based on a nematic liquid crystal

Liquid crystal (LC), a distinctive soft material that exhibits both fluid-like characteristics and crystalline anisotropy, has attracted significant interest in recent years due to its promising applications in radio frequency technologies. This paper introduces two multifunctional devices (MDs) utilizing nematic LC, specifically designed to operate across a range of temperatures. After an extensive characterization of the dielectric constant and loss tangent of the LC material (HSG14100-200), the LC-based MDs were developed based on well-established theoretical models. Within the temperature range of 40 °C to 180 °C, the MD incorporating a parallel-aligned LC cell demonstrated a peak resonant frequency shift of 0.16 GHz and a phase shift of 7.03°. In contrast, the MD with a perpendicular-aligned LC cell achieved a peak resonant frequency shift of 0.40 GHz and a phase shift of 20.53° over the same temperature range. Observations using a polarizing optical microscope revealed a distinct phase transition in both LC cells, providing direct evidence of its role in modulating dielectric properties. The ability to reconfigure both frequency and phase in the proposed MDs underscores the significant potential of LC in communication systems, particularly in the context of phased array and reconfigurable antennas. This work provides both a critical validation and a robust theoretical foundation, fostering further advancements in the radio frequency domain.