Millimeter-Wave Low-Profile Phase Shifter Based On Liquid Crystals

A low-profile phase shifter filled with liquid crystals (LCs) operating in millimeter-wave band is presented here. A spoof surface plasmon polaritons transmission line (SSPPs-TL) is introduced as the propagation structure for a smaller size. By introducing a biasing voltage, the relative dielectric constant of the LCs can be changed, and hence the phase constant of the SSPPs-TL will be changed as well, leading to a phase-shift ability. The proposed design is fabricated and measured, with a good consistence between the simulated and measured results.