A Tunable Metagratings Leaky-Wave Antenna Based on Liquid Crystal

Area of Science:

• Electromagnetics and Materials Science
• Antenna Engineering
• Metamaterials and Metasurfaces

Background:

• Traditional leaky-wave antennas (LWAs) face limitations in radiation angle control, often dependent on excitation frequency.
• Metagratings (MGs) offer a promising approach to enhance antenna performance and introduce novel functionalities.
• Liquid crystals (LCs) provide a tunable dielectric medium for electrically controlled electromagnetic applications.

Purpose of the Study:

• To propose and analyze an electrically tunable wide-beam-scanning antenna utilizing metagratings and liquid crystals.
• To investigate the suppression of open-stopband effects in metagratings leaky-wave antennas.
• To demonstrate the capability of continuous beam scanning through electrical tuning of liquid crystal permittivity.

Main Methods:

• Fabrication of a two-dimensional periodic slotted metagratings structure on a substrate with a ground plane.
• Theoretical analysis of equivalent electromagnetic fields generated by the slotted metagratings.
• Integration of liquid crystal material within the leaky-wave antenna framework for electrical tuning.

Main Results:

• Achieved wide tunable beam scanning up to 40° at a fixed frequency with a DC voltage range of 0 V to 10 V.
• Demonstrated continuous beam scanning of 71° over a 40% operating bandwidth at zero voltage, and 61° at saturation voltage.
• Obtained a realized gain of up to 13.84 dBi with a narrow beamwidth compared to conventional LWAs.

Conclusions:

• The proposed metagratings leaky-wave antenna offers wide tunable beam scanning capabilities, overcoming limitations of traditional LWAs.
• The integration of liquid crystals enables precise electrical control over the antenna's radiation characteristics.
• The antenna's performance makes it suitable for sensing communication and radar applications requiring precise calibration and range detection.