Frequency Selective Surface for Infrared Transmission Suppression at Atmospheric Window

2018 ◽  
Vol 937 ◽  
pp. 89-95
Author(s):  
Xiao Li Chen ◽  
Chang Hui Tian ◽  
Zhi Xin Che

A double screen infrared frequency selective surface (FSS) with dual transmission stopbands was proposed and numerically investigated. Simulation results show that the infrared transmittance of the structure is lower than 10% in mid-infrared band (3~5 μm) and far-infrared band (8 ~14 μm).This structure is polarization insensitive to the incident electromagnetic waves. For a wide range of incident angles from 0° to 60°, the infrared transmittance of the structure is still lower than 25% in the band of interest. Compared with black body, the radiation ratio of structure is lower in the MWIR and LWIR ranges. The structure provide the potential applications for infrared stealth.

2017 ◽  
Vol 62 (2) ◽  
pp. 1325-1328
Author(s):  
H.-S. Cho ◽  
S.-S. Kim

AbstractThis work investigates the effect of a frequency selective surface (FSS) composed of a regular array of square loop elements on the absorption properties of grounded ferrite composites. Polymer matrix composites of CoZnW hexaferrite powders having small magnetic loss were used as the substrate material. Computational tools were used to model the interaction between electromagnetic waves and materials and determine the reflection coefficient. Reflection loss and bandwidth were greatly improved by attaching an FSS with controlled electrical resistance (R) onto the grounded ferrite composites. For the FSS withR= 800 Ω, the minimum reflection loss decreased to −25 dB at 10 GHz and the bandwidth was broadened to 7.5-12.5 GHz with respect to −10 dB reflection loss.


Author(s):  
Mohamed Darwish

Electromagnetic waves can have serious effects on human health by long-term exposure. Developing lightweight materials with good electromagnetic radiation shielding (EMS) that could prevent interference is a high desire for protection. Nanocomposites polymers have a wide range of potential applications and offers suggested solutions in environmental and aerospace applications. This chapter will cover the current challenge in the reduction of electromagnetic wave by developing lightweight absorber material with a wide absorption frequency. A wide range of different nanocomposites polymers contain conductive fillers such as metal or magnetic nanoparticles and carbon-based materials will be discussed. In addition, EMS mechanisms of reflection, absorption, and multiple reflections will be discussed. The unique of the chemical and physical properties of nanocomposites polymers are promising for shielding with low-cost environmentally friendly material.


Author(s):  
Mohamed Darwish

Electromagnetic waves can have serious effects on human health by long-term exposure. Developing lightweight materials with good electromagnetic radiation shielding (EMS) that could prevent interference is a high desire for protection. Nanocomposites polymers have a wide range of potential applications and offers suggested solutions in environmental and aerospace applications. This chapter will cover the current challenge in the reduction of electromagnetic wave by developing lightweight absorber material with a wide absorption frequency. A wide range of different nanocomposites polymers contain conductive fillers such as metal or magnetic nanoparticles and carbon-based materials will be discussed. In addition, EMS mechanisms of reflection, absorption, and multiple reflections will be discussed. The unique of the chemical and physical properties of nanocomposites polymers are promising for shielding with low-cost environmentally friendly material.


Author(s):  
Ramprabhu Sivasamy ◽  
Balaji Moorthy ◽  
Malathi Kanagasabai ◽  
Jithila V. George ◽  
Livya Lawrance ◽  
...  

An ultra-wideband (UWB) frequency-selective surface (FSS) exhibiting band rejection characteristic is presented in this paper. The proposed unit cell has the size of 14 × 14 mm2 which is approximately 0.18 × 0.18 λo, where λo corresponds to free space wavelength at the lower cut-off frequency. The proposed UWB FSS consists of a single-layer substrate and provides 20 dB attenuation level for a wide bandwidth of 7.53 GHz at the normal incidence. The proposed FSS is polarization independent and also provides angular-independent operation for the EM wave incidences of 15°, 30° and 45° with 11.5 dB attenuation over a wide range from 4 to 14 GHz.


2020 ◽  
Vol 10 ◽  
pp. 184798042093571
Author(s):  
Guangsheng Deng ◽  
Kun Lv ◽  
Hanxiao Sun ◽  
Yuan Hong ◽  
Xiaoying Zhang ◽  
...  

In this article, a wideband, polarization-insensitive, and wide-incident-angle stable absorber based on conductive ink frequency selective surface is presented. The presented absorber is compatible with screen printing technology. The design and absorption principle of the proposed absorber is presented, and simulation analysis is conducted. The simulation results show that in the frequency range 6.58–16.38 GHz, the absorptivity of the proposed absorber is greater than 90%, while the relative absorption bandwidth is 85.4%. The whole absorber structure is relatively thin, having a total thickness of 3.3 mm, corresponding to 0.126λ0 at its center frequency. In addition, for both transverse electric and transverse magnetic incident waves, the proposed absorber achieves the absorptivity of more than 80% at the incident angle of up to 45°. A prototype of the proposed absorber is fabricated and used in experimental verification. The obtained experimental results show a good agreement with the numerical simulations. This absorber has great potential applications in the field of microwave sensing and absorbing.


Author(s):  
Yepu Cui ◽  
Ryan Bahr ◽  
Samantha Van Rijs ◽  
Manos Tentzeris

Abstract Shape-changing mechanical metamaterials have drawn the attention of researchers toward the development of continuous-range tunable frequency selective surfaces (FSSs). In this paper, a novel tunable FSS utilizing an origami-inspired “eggbox” structure is presented featuring four-degrees of freedom that can change the frequency response of two orthogonal linear polarizations. The centrosymmetric “eggbox” structure can be folded or rotated along two axes that lead to unprecedented reconfigurability compared to traditional Miura-Ori-based structures which have fewer degrees of control. The utilized cross-shaped dipole FSS element shows enhanced bandwidth, support for orthogonal linear polarization, and ease of fabrication. The prototype is fabricated using a low-cost fully additive inkjet printing process with silver nanoparticle conductive ink. The outcome of this study shows a 25% frequency tunable range over two polarization directions. The design can be an ideal spatial filtering candidate for advanced ultra-wideband terrestrial and space applications.


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