scholarly journals Wideband absorber based on conductive ink frequency selective surface with polarization insensitivity and wide-incident-angle stability

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.

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3016 ◽  
Author(s):  
Ximeng Zhang ◽  
Weiwei Wu ◽  
Chenxin Li ◽  
Chang Wang ◽  
Yuhong Ma ◽  
...  

In this paper, a dual-band terahertz absorber with two passbands is proposed. The absorber is composed of periodic patterned graphene arrays on the top of a SiO 2 substrate and a frequency selective surface (FSS) on the bottom of the substrate. The simulated results indicate that there are two absorption bands (absorption greater than 90%) ranging from 0.54 to 0.84 THz and 2.13 to 2.29 THz. It is almost transparent to incident waves (transmission greater than 50%) below 0.19 THz and between 1.3 and 1.67 THz with a center frequency of 1.49 THz. The absorber has a good tolerance to the transverse electric (TE) and transverse magnetic (TM) polarized wave oblique incidence, and the transmission rate of the passbands remains greater than 50% within 70 degrees. Moreover, the absorption rate of the absorber can be tuned by the chemical potential of graphene. The structure with absorption and transmission properties has potential applications in filtering, sensing, detecting and antenna stealth.


Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 476
Author(s):  
Umer Farooq ◽  
Adnan Iftikhar ◽  
Muhammad Farhan Shafique ◽  
Muhammad Saeed Khan ◽  
Adnan Fida ◽  
...  

This paper presents a highly compact frequency-selective surface (FSS) that has the potential to switch between the X-band (8 GHz–12 GHz) and C-band (4 GHz–8 GHz) for RF shielding applications. The proposed FSS is composed of a square conducting loop with inward-extended arms loaded with curved extensions. The symmetric geometry allows the RF shield to perform equally for transverse electric (TE), transverse magnetic (TM), and 45° polarizations. The unit cell has a dimension of 0.176 λ0 and has excellent angular stability up to 60°. The resonance mechanism was investigated using equivalent circuit models of the shield. The design of the unit element allowed incorporation of PIN diodes between adjacent elements for switching to a lower C-band spectrum at 6.6 GHz. The biasing network is on the bottom layer of the substrate to avoid effects on the shielding performance. A PIN diode configuration for the switching operation was also proposed. In simulations, the PIN diode model was incorporated to observe the switchable operation. Two prototypes were fabricated, and the switchable operation was demonstrated by etching copper strips on one fabricated prototype between adjacent unit cells (in lieu of PIN diodes) as a proof of the design prototypes. Comparisons among the results confirmed that the design offers high angular stability and excellent performance in both bands.


Circuit World ◽  
2019 ◽  
Vol 46 (1) ◽  
pp. 25-31
Author(s):  
Kanchana D. ◽  
Radha Sankararajan ◽  
Sreeja B.S. ◽  
Manikandan E.

Purpose A novel low profile frequency selective surface (FSS) with a band-stop response at 10 GHz is demonstrated. The purpose of this designed FSS structure is to reject the X-band (8-12 GHz) for the application of shielding. The proposed FSS structure having the unit cell dimension of 8 × 8 mm2, the miniaturization of the FSS unit cell in terms of λ0 is 0.266 λ0 × 0.266 λ0, where λ0 is free space wavelength. The designed FSS provides 4 GHz bandwidth with insertion loss of 15 dB. The transverse electric (TE) and transverse magnetic (TM) modes of the proposed design are same because of polarization independent characteristics and hold the angularly stable frequency response for both TE and TM mode polarization. Both the simulation and measurement results are in good agreement to each other. Design/methodology/approach The proposed FSS design contains square-shaped PEC material, which is placed on the substrate and the shape of the circle and rectangle is etched over the PEC material. The PEC material of the patch dimension is 0.0175 mm. The substrate used for the proposed design is FR4 lossy with the thickness of 0.8 mm and permittivity εr = 4.3 having a loss tangent of 0.02. Findings To find a new design and miniaturized FSS structure is discussed. Originality/value 100%


2009 ◽  
Vol 51 (10) ◽  
pp. 2513-2516 ◽  
Author(s):  
Hong-Yu Yang ◽  
Shu-Xi Gong ◽  
Peng-Fei Zhang ◽  
Feng-Tao Zha ◽  
Jin Ling

Author(s):  
Amit Birwal ◽  
Sanjeev Singh ◽  
Binod Kumar Kanaujia

Abstract In this paper, a novel design of ultra-wide stop-band single-side single-layer frequency selective surface (FSS) is presented. The unit cell of the proposed FSS is designed using the combination of conventional square loop and cross (CSLC). To enhance the bandwidth of this structure, an additional cross is inserted in all the four quadrants of CSLC. The stop-band transmission bandwidth assuming −10 dB threshold is found to be 128.94% (2.16–10 GHz) which is 34.33% more as compared to the bandwidth of CSLC. The unit cell with a dimension of 16 × 16 mm2 is printed on one side of an FR4 substrate. The design is fabricated and the measured results are found to be in good agreement with the simulated results. The design provides excellent stability for both transverse magnetic and transverse electric polarizations. The design is very flexible, where any resonant frequency can be achieved by changing the length of unit cell. The design is useful in many applications such as antenna gain enhancement, electromagnetic wave shielding for Wi-Fi/5G systems, and other Internet of Things-based applications.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Zhang ◽  
Jian-ying Li ◽  
Jian Xie

A broadband linear-to-circular transmission polarizer using a right-angled frequency selective surface is presented in this paper. The new proposed polarizer has both advantages of wide operational bandwidth and high transmission coefficients. To verify the design, a new polarizer working in X-band is optimized and fabricated. Experimental results show that the measured axial ratios lower than 3 dB range from 6.42 to 13.70 GHz, with low insertion loss. Meanwhile, the polarizer can operate over a broad range of frequencies from 6.75 to 10.75 GHz, when the incident angle increases to 25°.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 640
Author(s):  
Yi Lu ◽  
Juan Chen ◽  
Jianxing Li ◽  
Wenjing Xu

In high-power microwave applications, the electromagnetic-thermal effect of frequency selective surface (FSS) cannot be ignored. In this paper, the electromagnetic-thermal coupling effects of cross-slot FSS were studied. We used an equivalent circuit method and CST software to analyze the electromagnetic characteristics of cross-slot FSS. Then, we used multi-field simulation software COMSOL Multiphysics to study the thermal effect of the FSSs. To verify the simulation results, we used a horn antenna with a power of 20 W to radiate the FSSs and obtain the stable temperature distribution of the FSSs. By using simulations and experiments, it is found that the maximum temperature of the cross-slot FSS appears in the middle of the cross slot. It is also found that the FSS with a narrow slot has severer thermal effect than that with a wide slot. In addition, the effects of different incident angles on the temperature variation of FSS under TE and TM polarization were also studied. It is found that in TE polarization, with the increase in incident angle, the maximum stable temperature of FSS increases gradually. In TM polarization, with the increase in incident angle, the maximum stable temperature of FSS decreases gradually.


Author(s):  
F.H.W. Mustafa ◽  
S.N. Azemi ◽  
M.F. Jamlos ◽  
A.A. Al-Hadi ◽  
P.J. Soh

Structural health monitoring (SHM) technologies have attained attention to monitor civil structures. SHM sensor systems have been used in various civil structures such as bridges, buildings, tunnels and so on. However the previous sensor for SHM is wired and encounter with problem to cover large areas. Therefore, wireless sensor was introduced for SHM to reduce network connecting problem. Wireless sensors for Structural Health monitoring are new technology and have many advantages to overcome the drawback of conventional and wired sensor. This project proposed passive wireless SHM sensor using frequency selective surface (FSS) as an alternative to conventional sensors. The electromagnetic wave characteristic of FSS will change by geometrical changes of FSS due to mechanical strain or structural failure. The changes feature is used as a sensing function without any connecting wires. Two type of design which are circular ring and square loop along with the transmission and reflection characteristics of SHM using FSS were discussed in this project. A simulation process has shown that incident angle characteristics can be use as a data for SHM application.


Sign in / Sign up

Export Citation Format

Share Document