Performance and electromagnetic mechanism of radar- and infrared-compatible stealth materials based on photonic crystals

Traditional stealth materials do not fulfill the requirements of high absorption for radar waves and low emissivity for infrared waves. Furthermore, they can be detected by various technologies, considerably threatening weapon safety. Therefore, a stealth material compatible with radar and infrared was designed based on the photonic bandgap characteristics of photonic crystals. The radar stealth layer (bottom layer) is a composite of carbonyl iron/silicon dioxide/epoxy resin, and the infrared stealth layer (top layer) is a 1D photonic crystal with alternately and periodically stacked germanium and silicon nitride. Through composition optimization and structural adjustment, the effective absorption bandwidth of the compatible stealth material with a reflection loss of less than −10 dB has reached 4.95 GHz. The average infrared emissivity of the proposed design is 0.1063, indicating good stealth performance. The theoretical analysis proves that photonic crystals with this structural design can produce infrared waves within the photonic bandgap, achieving high radar wave transmittance and low infrared emissivity. Infrared stealth is achieved without affecting the absorption performance of the radar stealth layer, and the conflict between radar and infrared stealth performance is resolved. This work aims to promote the application of photonic crystals in compatible stealth materials and the development of stealth technology and to provide a design and theoretical foundation for related experiments and research.