Analyses of Nematic Liquid Crystal Molecule Motion and Response Characteristics in Microstripline-Type Microwave Phase Shifter

Abstract

In this paper, we propose an improved calculation method for analyzing the three-dimensional motion of nematic liquid crystal molecules in studies of all types of microwave transmission line loaded with a nematic liquid crystal. This method is applied to the analysis of motion of nematic liquid crystal molecules under a nonuniformly distributed electric field generated by asymmetric electrodes in a microstripline structure as a comprehensive example. Then, the dielectric constant distribution of the nematic liquid crystal layer, the effective dielectric constant in a microwave electric field, and the phase shift of a microwave in the microstripline loaded with a nematic liquid crystal are calculated. The rise time, decay time, and phase shift of a microwave phase shifter using a microstripline loaded with a nematic liquid crystal are also calculated. The differences in these response characteristics and their dependences on the width of the center conductor of the microstripline are determined by calculation and confirmed by performing experiments on the microwave phase shifters and an optical experiment on the retardation of the microstripline loaded with a nematic liquid crystal structure.

NRD waveguide-type terahertz phase shifter using nematic liquid crystal

“…[3][4][5][6][7][8][9][10][11] The properties of microwave and millimeter wave devices with various types of transmission line and LC have been studied. Examples of such devices are a microwave phase shifter using a microstripline loaded with an LC, [12][13][14][15] a microwave variable phase shifter using a coplanar waveguide loaded with an LC, 14,[16][17][18][19][20] and a microwave phase shifter using a rectangular waveguide loaded with an LC. 21) On the other hand, a non-radiative dielectric (NRD) waveguide is a practical line for the millimeter wave band.…”