Material survey for a millimeter-wave absorber using a 3D-printed mold

Area of Science:

• Materials Science
• Electromagnetics
• Cryogenics

Background:

• Radio absorptive materials (RAMs) are crucial for millimeter-wave receivers.
• A previous study established a 3D-printed mold method for RAM production, offering material flexibility.
• Cryogenic conditions are essential for certain sensitive receiver applications.

Purpose of the Study:

• To evaluate the performance of various absorptive materials integrated into a base epoxy resin (STYCAST-2850FT).
• To assess the optical performance of the resultant RAMs under cryogenic conditions (77 K).
• To identify optimal RAM formulations for millimeter-wave applications within a wide frequency range.

Main Methods:

• Incorporation of diverse absorptive materials into a STYCAST-2850FT epoxy base.
• Fabrication of RAM samples using a previously established 3D-printed mold technique.
• Measurement of RAM reflectance across a 20-300 GHz frequency range at 77 K.

Main Results:

• The addition of a specific type of carbon fiber yielded the best radio absorptive properties.
• The optimized RAM exhibited a reflectance of 0.01%-3% at 77 K.
• This performance was maintained across the tested 20-300 GHz frequency spectrum.

Conclusions:

• A specific carbon fiber-enhanced epoxy resin provides excellent radio absorptive properties at cryogenic temperatures.
• The 3D-printed mold method allows for flexible material selection to optimize RAM performance.
• These findings are significant for developing advanced millimeter-wave receivers operating under cryogenic conditions.