Ultra-thin and omnidirectional reflectionless absorbing surface working at dual-frequency

ABSTRACT

Materials with characteristics of omnidirectional reflectionless absorption are of great importance in electromagnetic shielding and anechoic chamber. Recently emerged absorbing surfaces mostly work at a given angle, and absorbers working at a broad frequency band usually suffer from a 3-D structure. Thus, the fabrication of the ultra-thin and omnidirectional reflectionless absorber working at dual-frequency remains a technical challenge. In this work, we demonstrated the absorbing performance of an ultra-thin slab under different incident angles of the electric fields, and an approximate solution was derived to prove the realizability of the dual-frequency and omnidirectional reflectionless absorption. For illustration, a miniaturized dual-frequency anechoic chamber with a 343.8 mm diameter was constructed, and the full-wave simulations validated the results. The proposed design method is simple and robust, which provides a new clue for solving the practicability difficulty faced by existing anechoic chambers and microwave imaging systems.

KEYWORDS:

• Ultra-thin
• dual-frequency
• reflectionless absorption
• anechoic chamber

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 62101288], Natural Science Research Project of Colleges and Universities of Anhui Province [grant number 2022AH050073] and Program for Excellent Scientific and Innovation Research Team [grant number 2022AH010002].