Wideband Transmissive Frequency-Selective Absorber

• Published in: IEEE antennas and wireless propagation letters 2019-07, Vol.18 (7), p.1443-1447
• Main Authors: Wang, Zhefei, Fu, Jiahui, Zeng, Qingsheng, Song, Mingxin, Denidni, Tayeb Ahmed
• Format: Article
• Language: English
• Subjects: Absorbers; Absorption; Absorption spectra; Absorptivity; Bandwidth; Bandwidths; Broadband; Computer simulation; Frequency selective surfaces; Frequency-selective absorber; Insertion loss; Propagation losses; Reduction; Reflection; reflection reduction; Resistors; Resonant frequency; second order; tri-resonant absorption; wideband transmission
• ISSN: 1536-1225; 1548-5757
• DOI: 10.1109/LAWP.2019.2919633

In this letter, a new frequency-selective absorber is presented that has wideband transmission/absorption/reflection reduction responses. The presented absorber is completed by lossy cross-dog-bone and lossless second-order frequency-selective surfaces. The modal interaction pole generated by the lossy array is employed to achieve a wideband transmission. Three absorption bands are combined to realize a continuous stopband with high absorptivity. Furthermore, the improved absorber structure is investigated to reduce the strong reflection between the absorption and transmission bands. The 10 dB reflection reduction is obtained with a fractional bandwidth of 126.4%. Meanwhile, the -3 dB fractional passband width is 41.3% with minimum insertion loss of 0.37 dB. The absorption bandwidth of 91.5% is provided with at least 90% absorptivity. The distance between the lossy and lossless layers is only 0.08 \lambda _{L} at the lowest operating frequency. Finally, the proposed design is validated by a good agreement between the numerical simulations and experimental measurements.