Fast Response and Miniaturized Phase Shifter Based on Liquid Crystal

In this paper, a fast response and miniaturized phase shifter is proposed based on liquid crystals (LCs). The proposed phase shifter is implemented utilizing a slot line-based loaded line structure. The high characteristic impedance of the slot line effectively enhances the phase-shifting capability per wavelength, facilitating the miniaturized design. A cascaded ABCD matrix is employed to analyze the electromagnetic characteristics of the periodic unit, guiding the phase shifter design. In addition, a high-impedance bias network is adopted to apply DC bias. The experimental validation illustrates that the proposed phase shifter achieves a phase shift of 225° per wavelength at 14.125 GHz. The reflection coefficient <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\vert S_{11}$</tex> remains below -10 dB across the 13 GHz to 15 GHz, and the figure of merit (FoM) reaches 118.7°/dB at 14.125 GHz. Furthermore, the millisecond-level response time provides additional competitive advantages for high-frequency applications, particularly in potential uses for satellite communications and radar systems.