Active continuous control of terahertz wave based on a reflectarray element-liquid crystal-grating electrode hybrid...

Area of Science:

• Terahertz (THz) technology
• Metamaterials and Plasmonics
• Liquid Crystal (LC) devices

Background:

• Terahertz (THz) technology requires efficient phase control for applications like reconfigurable antennas.
• Existing THz phase shifters often face limitations in tunability and efficiency.
• Liquid crystals offer a promising medium for tunable electromagnetic devices due to their controllable dielectric properties.

Purpose of the Study:

• To propose and demonstrate a new, efficient terahertz reflective phase shifter.
• To achieve continuous phase manipulation of terahertz waves using liquid crystals.
• To explore the potential of this device for terahertz reconfigurable antennas.

Main Methods:

• Fabrication of a metal-dielectric-metal structure with a double dipole patch array.
• Integration of copper grating electrodes within a nematic liquid crystal layer.
• Application of separate external bias voltages to cross-distributed comb grids to control the electric field in the LC layer.
• Utilizing an innovative technique to continuously alter the electric field and LC molecule orientation.

Main Results:

• The proposed phase shifter achieved continuous phase manipulation of the reflective electromagnetic wave.
• Experimental results showed a phase shift exceeding 180° within the 102.5-104.3 GHz frequency range.
• A maximum phase shift of 249° was recorded at 103 GHz.

Conclusions:

• The developed terahertz reflective phase shifter offers efficient and continuous phase control.
• The device provides a new regulation concept for liquid crystal-based terahertz devices.
• This technology holds significant potential for applications in terahertz reconfigurable antennas.