Wide-angle, dual-polarized frequency selective rasorber based on the electric field coupled resonator using characteristic mode analysis

Abstract

A wide-angle, dual-polarized frequency selective rasorber (FSR) with two absorption bands located at both sides of a passband is proposed. The structure comprises a lossy frequency selective surface (FSS), a bandpass FSS, and an air spacer located in between. A modified electric field coupled (ELC) resonator is used as a parallel resonance at the lossy layer to achieve a passband within the absorption band. The characteristic mode theory is utilized to investigate the absorption behavior of the lossy layer. Extensive simulations were carried out to assess the performance of the presented structure. Under the normal incidence, the proposed structure provides an operating bandwidth (|S11| < −10 dB) from 1.94 to 7.16 GHz, corresponding to a fractional bandwidth (FBW) of 114.7%. The achieved passband is around 4.3 GHz with a minimum insertion loss of 0.81 dB. The absorption bands with an absorption rate higher than 80% are 1.81–3.69 GHz (FBW of 68.4%) in the lower band and 4.95–7.43 GHz (FBW of 40%) in the upper band, respectively. It exhibits quite stable characteristics up to 50° angle of incidence. Furthermore, a prototype was fabricated and measured, which confirms that a good agreement exists between the experimental and simulation results. The proposed FSR is a suitable candidate for lowering the radar cross section (RCS) of the communication equipment or making them stealthy.

Wideband metasurface-loaded rectenna for azimuth-insensitive electromagnetic energy absorption using characteristic mode analysis

“…13 The method has been widely applied in the research of MTSs, which provides a sound theory for researchers. 14,15 Therefore, the inherent pattern of the designed MTS-loaded rectenna can be screened using CMA to obtain the specific desired radiation pattern after excitation. 16,17 Therefore, the CM theory is applied to explore the primitive properties of the system.…”

A Tunable Frequency Selective Rasorber with Broad Passband and Low Transmission Loss at X-Band

“…In recent years, several designs for FSRs have emerged due to their selective transmission and strong stealth features. FSRs can be categorized into three groups according to the spectral positions of the passband and the absorption band: low-pass-high-absorption devices [15][16][17], high-pass-low-absorption devices [13,14,18], and bandpass devices with highand low-absorption bands [19][20][21][22]. These designs are tailored to meet the requirements of antenna stealth in various radar systems.…”

“…The 3D model [23] offers high design freedom and structural strength but faces challenges related to complicated processing and high production costs. On the other hand, the 2D model [19,24,25], which consists of a three-layer structure, has minimal insertion loss in the top and bottom layers with no loss for electromagnetic waves in the center dielectric layer. Convoluted resonators [24], circular spiral resonators [18], and other structures have been proposed.…”