Design of switchable band‐notched frequency selective absorber

Abstract

An active band‐notched frequency selective absorber (BNFSA) with switchable notch band is proposed in this article. The BNFSA is a two‐layer structure composed of a lossy layer at the top and a ground plane at the bottom, separated by an air spacer. The element of the lossy layer is a lumped‐resistor‐loaded metallic dipole with a parallel LC resonance structure, which is realized by complementary n‐shaped resonator (CnR) inserted in the center, and PIN diode is welded at two arms of CnR. The bias circuit printed on the back of the substrate of the lossy layer connects to anode and cathode of the diode by via hole and isolates by the inductor. Simulation results show that the notch bands are located at 4.50 and 6.81 GHz when the diode sets to ON and OFF, respectively. To validate the performance of switchable BNFSA, the prototypes are fabricated and measured, reasonable agreement between simulated and measured results is obtained.

Band‐notched frequency‐selective absorber with linear polarization rotation function

“…Reference 11 realizes both the wide reflection band and the wide absorption band. References 12,13 can switch EM waves from reflection state to absorption state. However, the structure in Reference 12 does not have the out‐of‐band absorption function, and the design in Reference 13 is polarization‐sensitive.…”

“…References 12,13 can switch EM waves from reflection state to absorption state. However, the structure in Reference 12 does not have the out‐of‐band absorption function, and the design in Reference 13 is polarization‐sensitive. To switch between the three working modes, PIN diodes are utilized 14 .…”

Switchable rasorber with high‐order frequency selective surface for transmission bandwidth extension

“…This concept was later extended to dual‐polarized design by G. Qian et al 9 Besides, S. Bakshi et al presented a switchable T‐A rasorber by loading PIN diodes in FSS only 8 . Moreover, M. Guo et al presented a switchable band‐notched absorber through loading the PIN diodes in resistive layer for the RCS reduction of reflector antenna 17 . However, although these existing switchable devices can achieve effective in‐band RCS reduction, all of them exhibit narrow passbands that cannot fulfill the requirement of broadband systems.…”

Design of a frequency selective rasorber with fast roll‐off and wide absorption/transmission band

“…The frequency selective surface (FSS), a kind of 2D/3D periodic structure, has been extensively investigated in last decades 1‐3 . Due to its unique frequency filtering characteristics, they are widely applied in a variety of important applications, such as stealth radomes, 4 reduction for radar cross section (RCS), 5 absorbers, 6,7 and applications in shielding 8,9 …”