Continuous Beam Steering Through Broadside Using Asymmetrically Modulated Goubau Line Leaky-Wave Antennas

Area of Science:

• Electromagnetics and Wave Propagation
• Antenna Theory and Design
• Metamaterials and Periodic Structures

Background:

• Goubau lines offer easy integration and low-loss transmission.
• Leaky-wave antennas (LWAs) enable beam steering but often have low broadside efficiency.

Purpose of the Study:

• To propose and validate a periodic leaky-wave antenna based on a planar Goubau transmission line.
• To enhance the radiation efficiency of Goubau line LWAs, particularly at the broadside direction.

Main Methods:

• Introducing periodic modulations to a planar Goubau transmission line to generate leaky-wave radiation.
• Employing both transversally and longitudinally asymmetrical modulations to improve broadside radiation efficiency.
• Conducting theoretical analysis, numerical simulations, and experimental validation.

Main Results:

• Periodic modulations enable surface waves to radiate by entering the fast-wave region.
• Asymmetrical modulations significantly improve radiation efficiency at the broadside direction compared to symmetrical designs.
• Experimental results closely match numerical simulations, validating the proposed LWA structures.

Conclusions:

• The proposed Goubau line LWAs with asymmetrical modulations offer improved performance.
• These LWAs demonstrate continuous beam steering capabilities from backward to forward.
• The validated structures show potential for applications in millimeter-wave and terahertz systems.