Liquid Crystal-Based Ku-Band Polarization Reconfigurable Antenna

This paper presents a polarization reconfigurable antenna based on liquid crystal (LC) operating at around 14 GHz in the Ku-band. The antenna consists of two orthogonally-positioned defected ground structure (DGS) phase shifters loaded with LC together with a square radiating patch. By adjusting the permittivity of the loaded LC, the two DGS phase shifters can induce phase delays of 0°, +90° and -90° to the orthogonal radiating modes. This allows for the reconfiguration of the polarization states of the radiated far field from linear to right/left-handed circularly polarized state, correspondingly. The proposed antenna is fabricated using process compatible with the liquid crystal display (LCD) technology, ensuring that the antenna can be integrated into the existing manufacturing process. The simulated and measured results of the antenna indicate good polarization reconfiguration performances at Ku-band and can be further extended to higher frequencies in the millimeter wave regime.