Microwave Liquid Crystal Technology

Abstract

Tunable Liquid Crystal (LC)-based microwave components are of increasing interest in academia and industry. Based on these components, numerous applications can be targeted such as tunable microwave filters and beam-steering antenna systems. With the commercialization of first LC-steered antennas for Ku-band e.g., by Kymeta and Alcan Systems, LC-based microwave components left early research stages behind. With the introduction of terrestrial 5G communications systems, moving to millimeter-wave communication, these systems can benefit from the unique properties of LC in terms of material quality. In this paper, we show recent developments in millimeter wave phase shifters for antenna arrays. The limits of classical high-performance metallic rectangular waveguides are clearly identified. A new implementation with dielectric waveguides is presented and compared to classic approaches.

77‐1: Invited Paper: Liquid Crystals beyond Displays: Smart Antennas and Digital Optics

“…as an inverted microstrip line, loaded line or microwave coupler-based structure. Also, non-planar structures with larger LC volumes have been reported in literature [4].…”

Design Optimization of Reconfigurable Liquid Crystal Patch Antenna

“…Here, we propose applying a liquid crystal to a frequency tunable patch antenna for a microwave frequency band. This liquid crystal is being actively studied in the field of an antenna for variable frequency [ 16 , 17 , 18 , 19 , 20 ] and an electronic beamforming antenna for the mm-wave frequency band [ 21 , 22 , 23 , 24 , 25 , 26 ]. However, research on technology for securing antenna performance while using an expensive liquid crystal to a minimum is still insufficient [ 27 ].…”

Wideband Reconfigurable Millimeter-Wave Linear Array Antenna Using Liquid Crystal for 5G Networks

“…The LCs can be used only in the nematic phase for designing electronically tunable RF, microwave, and mmw devices. The use of LCs in mmw devices represents a novel method for achieving frequency agility or pattern and polarization reconfigurability and multi-functional tunability [13]. These tunable anisotropic materials have been targeted in the last few years for the design of reconfigurable antennas [14] [15], resonators [16], phase shifters [17], and filters [18].…”