Low-Voltage Controlled Fast Switchable Liquid-Crystal-Based Reflectarray With Transverse Rubbing Layer

This letter proposes a low-voltage controlled fast beam switchable liquid-crystal-based reflectarray (LC-RA). By introducing a strip array of ground patterns and a transverse rubbing layer, a 1.5 V-powered falling response can be achieved for fast beam switching. Typically, the falling response of the LC cannot be controlled by the bias voltage, leading to slow beam switching. The strip array, in conjunction with the top electrodes, generates lateral fields for arranging the molecules of the LC, enabling the falling nature to be controlled by the bias voltage. In addition, the transverse rubbing layer achieves a low voltage-based fast-falling response without degradation of antenna performance. This study demonstrates the antenna performance and switching speed of the proposed LC-RA and compares it with other LC-based antennas. Finally, the proposed antenna achieves 1.6 s of switching speed with under bias voltage of 5 V for the beamforming. Moreover, the proposed design shows high antenna performance, such as aperture efficiency, SLL, and scanning range, compared to the LC-based antennas at the millimeter-wave (mmWave) band.