Miniaturized frequency selective rasorber with a X‐band transmission band using cross band resonator

Abstract

This article designs a miniaturized frequency selective absorber (FSR) based on X‐band. The FSR consists of a resistor sheet and a bandpass frequency selective surface (FSS). It has a wide low frequency absorption band and a low insertion loss wide high frequency transmission band. The resistor element is a hexagonal metal ring with lumped resistance. Each side of the ring is inserted with three cross metal branches. The branch is equivalent to the λh/4 short‐circuit branch. Three types of branches with different lengths can be used to achieve wide‐band transmission. The band‐pass FSS is a three‐layer structure, which is composed of two layers of circular metal patches and a layer of circular aperture. The band‐pass FSS must coincide with the transmission band of the resistor sheet. The resistor sheet is placed on the band‐pass FSS. At low frequencies, FSR functions as an absorber. The absorption bandwidth of 10 dB is 2.2 to 6.3 GHz. At high frequencies, the transmission band is almost transparent. At this time, the 1 dB transmission bandwidth is 8.1 to 12.1 GHz. FSR has good angular stability and polarization stability. A prototype of the structure was made and measured to verify the correctness of the design.

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

“…The lossy layer composed of graphene‐based planar resistor 18 provide an excellent roll‐off, whose is 1.2. But the absorption performance is achieved by graphene flake, which will result in the increase of fabrication cost.…”

An ultra‐wide passband frequency‐selective rasorber with high transmission

“…Actually, the wide passband peculiarity of the FSR is an important index when it is worked as stealthy radomes of the antenna system. The FSRs with broad transmission band have been exposed, such as the cross‐dog bone structure, 14 circular spiral resonator, 11 convoluted resonator, 15 and cross metal branches resonator 16 . However, the bandwidth and insertion loss of the FSRs mentioned above need to be improved.…”

“…The FSRs with broad transmission band have been exposed, such as the cross-dog bone structure, 14 circular spiral resonator, 11 convoluted resonator, 15 and cross metal branches resonator. 16 However, the bandwidth and insertion loss of the FSRs mentioned above need to be improved.…”

Dual‐polarized frequency selective rasorber with broadband absorption and transmission

“…It consists of resistive sheet, dielectric layer and metallic ground plane), the lossless layer almost totally reflects the incident EM wave to perform a metallic ground plane of CAA, and the lossy layer absorbs the incident EM wave 9 . Various 2‐D FSRs have been reported recently, which possess excellent spatial filtering and absorption performances 10–22 . For example, the FSRs with absorption bands located on both sides of the transmission band are presented in Han et al 10–13 But their transmission bandwidth is generally narrow, which will result in wide transition bandwidth between passband and absorption, thus causing rise of reflection in the transition band.…”

“…However, the traditional CAA layer usually owns high insertion loss at transmission band. Furthermore, a lot of FSRs with the absorption band below the passband are reported 17–22 . For example, in Jia et al, 16 the FSR realized broadband transmission with convoluted resonator but its absorption band is relatively narrow.…”