The low RCS level out of operating band is urgent for radome while keeping its communication window.To solve this problem, we propose a frequency selective rasorber (FSR) that Ship Model Kit exhibits a pass-band between two absorption bands in this paper.The surface currents on a finite metallic wire media is analyzed firstly to elaborate transverse standing waves mechanism.
High-efficiency and broadband absorption can be achieved by loading lumped resistors at high amplitude of standing waves.By delicately engineering the transverse standing waves versus frequency, a transparent window can be opened within an absorption wideband and it can be modulated by adjusting structural parameters.The transparent Nails window centered around 10.
0 GHz in the absorption band from 5.8 GHz to 18.0 GHz.
Prototypes were fabricated and measured.Both the simulated and measured results show that for both x- and y-polarized waves, insertion loss of the transparent window at 9.85 GHz is below 0.
2 dB while the absorption is above 90% in the two sidebands of 5.8-7.8 GHz and 11.
8-18.0 GHz.Furthermore, the rasorber can also work well under oblique incidence angles up to 45 degrees.
This work may find wide applications in electromagnetic compatibility, stealthy radomes, etc.