Time-Modulated Transmissive Programmable Metasurface for Low Sidelobe Beam Scanning

Area of Science:

• Electromagnetics and Metamaterials
• Applied Physics
• Information and Communication Technology

Background:

• Programmable metasurfaces offer low-cost phased array solutions.
• Conventional metasurfaces struggle with high sidelobe levels (SLL) due to limited phase control.
• Achieving precise phase control is crucial for advanced antenna applications.

Purpose of the Study:

• To introduce a time modulation strategy for 1-bit transmissive programmable metasurfaces.
• To reduce the sidelobe level (SLL) in metasurface-generated radiation patterns.
• To enhance the phase shift accuracy for improved metasurface performance.

Main Methods:

• Implementing periodic time modulation in a 1-bit transmissive programmable metasurface.
• Generating and controlling first-order harmonics for dynamic phase shifts.
• Utilizing high-speed modulation sequences and programmable bias circuits.
• Achieving an equivalent 6-bit phase shift accuracy per metasurface unit.

Main Results:

• Demonstrated a significant reduction in sidelobe levels (SLL) to approximately -20 dB.
• Achieved an aperture efficiency exceeding 34% in the transmissive programmable metasurface.
• Verified the time-modulated strategy through numerical simulations and experimental validation.
• Showcased the dynamic control of phase for first-order harmonics.

Conclusions:

• The proposed time modulation strategy effectively reduces SLLs in programmable metasurfaces.
• This method enhances phase accuracy, enabling higher performance for phased arrays.
• The developed framework presents a novel approach for radar and secure communication systems.