A low-profile EIA-like rasorber with ultra-wideband transmission band

In this article, based on the theory of electromagnetic induced transparency (EIT) and electromagnetic induced absorption (EIA), a novel frequency selective rasorber (FSR) is proposed. This dual-polarized structure has an ultra-wideband transmission band in-between two absorption bands. When the bright mode resonant circuit (BMRC) is excited by incoming electromagnetic (EM) waves operating in the absorption bands, the EM energy is transferred to the dark mode resonant circuit (DMRC) by EM induction and coupling. The lumped resistors (LRs) of the DMRC absorb the coupled EM energy. The incoming EM waves at other frequencies will pass this proposed EIA-like FSR with low insertion loss (IL). Its transmission band is from 14.6 GHz to 18.2 GHz. Its absolute bandwidth is 3.6 GHz and the relative bandwidth is 22%. The absorption bands occur from 13.2 GHz to 14 GHz and from 18.7 GHz to 19.4 GHz. The RCS reduction range is from the minimum value of 2.63 dB at 10 GHz to the maximum value of 23.28 dB at 19.3 GHz. The unit cell has a dimension of 10 X 10 X 3 mm, which means its total thickness is only 3 mm. This proposed EIA-like FSR can be a good candidate both in radar stealth radome and EM compatibility domains.