Microwave-transparent metallic metamaterials for autonomous driving safety

Area of Science:

• Metamaterials
• Electromagnetics
• Automotive Engineering

Background:

• Transparent heaters are crucial for autonomous driving safety in extreme weather.
• Achieving high transmittance and low sheet resistance simultaneously in transparent heaters is a significant challenge.

Purpose of the Study:

• To develop microwave-transparent, low-sheet-resistance heaters for automotive radar applications.
• To overcome the inherent trade-off between transmittance and sheet resistance in transparent heater technology.

Main Methods:

• Designing ultrathin, electrically connected metamaterials inspired by metamaterial design principles.
• Integrating metamaterials onto a millimetre-thick dielectric cover for W-band (75-110 GHz) operation.
• Utilizing metamaterials to achieve desired phase delay and adjust Fabry-Perot resonance.

Main Results:

• Achieved near-unity transmission at specific W-band frequencies with a metal filling ratio over 70%.
• Fabricated heaters demonstrated exceptionally low sheet resistance (0.41 ohm/sq).
• Heaters effectively raised the dielectric cover temperature above 180°C at 3V bias, capable of defrosting ice layers.

Conclusions:

• Metamaterial-based transparent heaters offer a viable solution for maintaining automotive radar performance in adverse weather conditions.
• The developed heaters provide excellent thermal performance and defrosting capabilities while maintaining microwave transparency.