MDPI - Publisher of Open Access Journals

13 pages, 3133 KB

Open AccessArticle

A Miniaturized Ultrawideband Frequency-Selective Rasorber with High Absorptivity

by Jiayao Luo, Hao Wen, Liping Yan, Xiang Zhao and Changjun Liu

Microwave 2026, 2(2), 6; https://doi.org/10.3390/microwave2020006 - 24 Mar 2026

Cited by 1 | Viewed by 579

To overcome the intrinsic trade-off among miniaturization, ultrawideband (UWB) performance, and structural simplicity in conventional frequency-selective rasorber (FSR) design, this paper proposes a miniaturized UWB absorption–transmission–absorption (A-T-A) FSR based on an inter-cell current-interaction mechanism. The structure comprises a dielectric matching layer (DML), a [...] Read more.

To overcome the intrinsic trade-off among miniaturization, ultrawideband (UWB) performance, and structural simplicity in conventional frequency-selective rasorber (FSR) design, this paper proposes a miniaturized UWB absorption–transmission–absorption (A-T-A) FSR based on an inter-cell current-interaction mechanism. The structure comprises a dielectric matching layer (DML), a lossy frequency-selective surface (FSS), a lossless FSS layer, and air/dielectric spacers. Both FSS layers are fabricated on Rogers 4350B substrates without any metallized via or multiple lossy/lossless FSS stacking. The proposed FSR achieves a miniaturized structure with dimensions of 0.085 λ_L × 0.085 λ_L × 0.118 λ_L (where λ_L corresponds to the wavelength at the lowest absorption frequency). A fractional operational bandwidth around 144% is obtained, covering 2.88–12.87 GHz and 14.98–17.61 GHz with absorptivity over 80%, together with a low-loss transmission band of 13.57–14.56 GHz exhibiting a minimum insertion loss of 0.41 dB. As the incident angle increases up to 40°, the FSR retains more than 134% bandwidth for both TE and TM polarizations. A prototype was fabricated and measured, and the results agree well with the simulations. Full article

► Show Figures

Graphical abstract

15 pages, 4718 KB

Open AccessArticle

A Miniaturized and Highly Stable Frequency-Selective Rasorber Incorporating an Embedded Transmission Window

by Yi Li, Yuxi Zhong, Minrui Wang, Keqing Chen, Peng Ren and Zheng Xiang

Micromachines 2024, 15(8), 980; https://doi.org/10.3390/mi15080980 - 30 Jul 2024

Cited by 4 | Viewed by 1713

Abstract

In this article, a miniaturized and highly stable frequency-selective rasorber (FSR) incorporating an embedded transmission window is designed. This FSR consists of a lossy layer loaded with resistors, an air layer, and a bandpass layer. The lossy layer is provided with a rectangular, [...] Read more.

In this article, a miniaturized and highly stable frequency-selective rasorber (FSR) incorporating an embedded transmission window is designed. This FSR consists of a lossy layer loaded with resistors, an air layer, and a bandpass layer. The lossy layer is provided with a rectangular, square ring structure loaded with four

180 Ω

resistors and four quadrilateral metal plates. The four metal plates are connected to the four corners of the inner ring around the square ring and are radially distributed along the diagonal. The bandpass layer is a square metal patch that a cross-ring slot structure is loaded inside of, and the cross points lie in the direction along the diagonal of the unit. The inner boundary of the cross-ring is composed of two mutually perpendicular and long rectangular elements. This FSR shows an embedded transmission window from 3.63 GHz to 3.80 GHz and has a transmission rate of 93% at 3.72 GHz. Moreover, both sides of the transmission band, namely, 1.86–3.35 GHz and 3.99–8.28 GHz, have an absorption rate of more than 80% and bilateral relative bandwidth of more than 50%. In addition, this structure exhibits excellent miniaturization performance, polarization insensitivity, and angular stability. Finally, a prototype of the designed FSR is processed and measured. The measured results are basically consistent with the simulation results. Full article

(This article belongs to the Section D：Materials and Processing)

► Show Figures

Figure 1

21 pages, 10460 KB

Open AccessArticle

An Ultra-Wideband Frequency Selective Rasorber with Low Infrared Emissivity

by Hang Song, Yuning Zhang, Shengjun Zhang, Jingfeng Li, Xia Ai, Han Zhang and Jiaqi Liu

Materials 2024, 17(14), 3414; https://doi.org/10.3390/ma17143414 - 10 Jul 2024

Cited by 3 | Viewed by 2243

Abstract

The paper proposes an ultra-wideband frequency selective rasorber (FSR) with low infrared emissivity for the composite detection threat of both radars and infrared sensors. Firstly, the equivalent circuit (EC) method based on transmission line (TL) theory is utilized to analyze the absorption/transmission conditions. [...] Read more.

The paper proposes an ultra-wideband frequency selective rasorber (FSR) with low infrared emissivity for the composite detection threat of both radars and infrared sensors. Firstly, the equivalent circuit (EC) method based on transmission line (TL) theory is utilized to analyze the absorption/transmission conditions. Then, based on the analysis above, sinusoidal microstrip lines with non-frequency-varying characteristics are adopted in the design, which significantly enhances the transmission bandwidth of FSR. The FSR demonstrates an absorption band ranging from 2.65 GHz to 8.80 GHz and a transmission band ranging from 9.15 GHz to 17.71 GHz. Furthermore, an infrared shielding layer (IRSL) exhibiting low emissivity in the infrared band and high transmittance in the microwave band is applied to the FSR. The simulation and experiment results verify that the IRSL-FSR demonstrates an ultra-wide transmission band ranging from 9.16 GHz to 17.94 GHz and an ultra-wide absorption band ranging from 2.66 GHz to 8.01 GHz. Additionally, it exhibits a low emissivity value (0.23) in 8–14 μm, providing a viable solution to the formidable challenge of radar-infrared bistealth for satellites and other communication-enabled flying platforms. Full article

(This article belongs to the Section Electronic Materials)

► Show Figures

Figure 1

12 pages, 3420 KB

Open AccessArticle

A Switchable Frequency Selective Rasorber with a Broad Transmission Window at the X-Band

by Shengnan Shi, Zizhao Chai, Shan Zhang, Yanpeng Shi and Yifei Zhang

Electronics 2023, 12(18), 3941; https://doi.org/10.3390/electronics12183941 - 19 Sep 2023

Cited by 8 | Viewed by 2574

Abstract

This paper proposes a switchable polarization-insensitive frequency selective rasorber (FSR) within the X-band. The FSR comprises a lossy layer, a lossless layer, and an intermediate air layer. The lossy layer consists of metal patches, folded wires, and lumped resistors, while the lossless layer [...] Read more.

This paper proposes a switchable polarization-insensitive frequency selective rasorber (FSR) within the X-band. The FSR comprises a lossy layer, a lossless layer, and an intermediate air layer. The lossy layer consists of metal patches, folded wires, and lumped resistors, while the lossless layer is formed with square and cross patches loaded with PIN diodes. An equivalent circuit model (ECM) has been developed to analyze and verify the working principle of the system. By altering the state of the PIN diodes, it is feasible to switch between absorbing and transmitting modes. In the rasorber mode, the switchable FSR attains a transmission window ranging from 10.13 to 12.27

G H z

with a minimum insertion loss below 2

d B

and a broad absorption band covering 5.79–15.37

G H z

. When switched to absorber mode, the passband is negated, and the FSR exhibits a low transmission band from 10.68 to 18.00

G H z

. This innovation can improve the omni-directional stealth capability and battlefield survivability of radar systems, possessing substantial research importance and practical applications. Full article

(This article belongs to the Section Circuit and Signal Processing)

► Show Figures

Figure 1

11 pages, 3935 KB

Open AccessArticle

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

by Shengnan Shi, Zizhao Chai, Shan Zhang, Yanpeng Shi and Yifei Zhang

Materials 2023, 16(17), 5787; https://doi.org/10.3390/ma16175787 - 24 Aug 2023

Cited by 7 | Viewed by 2854

Abstract

In this paper, we propose a dual-mode frequency selective rasorber (FSR) with tunable transmission and absorption windows at the X-band, which shows a broad passband in each transmission window. The proposed tunable FSR consists of a lossy absorption layer, a lossless transmission layer, [...] Read more.

In this paper, we propose a dual-mode frequency selective rasorber (FSR) with tunable transmission and absorption windows at the X-band, which shows a broad passband in each transmission window. The proposed tunable FSR consists of a lossy absorption layer, a lossless transmission layer, and an air gap between them. The top frequency selective surface (FSS) layer is a cross-shaped meandering line with resistors and varactors for tunable absorption, and the bottom layer is a cross-shaped gap with varactors to achieve tunable bandpass. The equivalent circuit model (ECM) is investigated, and the 3D full wave simulation is performed. The results are based on simulations, and the simulation results show that the passband can be tuned from 12 to 8

G H z

with an insertion loss between 0.5 and 1.4

d B

by sweeping the capacitance of the varactors. The proposed design decreases the chances of detection by adversary devices and assures spectrum-safe communication, thereby creating new avenues for radar stealth and target concealment. Full article

► Show Figures

Figure 1

11 pages, 6700 KB

Open AccessArticle

Design of a Frequency Selective Rasorber Based on a Band-Patterned Octagonal Ring

by Xiaojun Huang, Yutao Ma, Xiaoyan Li, Linyan Guo and Helin Yang

Materials 2023, 16(5), 1960; https://doi.org/10.3390/ma16051960 - 27 Feb 2023

Cited by 9 | Viewed by 3247

Abstract

In this study, a dual-polarization and low-profile frequency-selective rasorber (FSR) constructed from a novel band-patterned octagonal ring and dipole slot-type elements is investigated. We show the process of designing from a full octagonal ring to realize a lossy frequency selective surface of our [...] Read more.

In this study, a dual-polarization and low-profile frequency-selective rasorber (FSR) constructed from a novel band-patterned octagonal ring and dipole slot-type elements is investigated. We show the process of designing from a full octagonal ring to realize a lossy frequency selective surface of our proposed FSR, and it has a passband with low insertion loss between the two absorptive bands. An equivalent circuit for our designed FSR is modeled to explain the introduction of the parallel resonance. Surface current, electric energy, and magnetic energy of the FSR are further investigated to illustrate the working mechanism. Simulated results indicate that S₁₁ < −10 dB bandwidth within 5.2–14.8 GHz, S₂₁ > −3 dB passband within 9.62–11.72 GHz, lower absorptive bandwidth within 5.02–8.80 GHz, and upper absorptive bandwidth within 12.94–14.89 GHz are obtained under normal incidence. Meanwhile, our proposed FSR possesses the properties of dual-polarization and angular stability. To verify the simulated results, a sample with thickness of 0.097 λ_L is manufactured, and the results are experimentally verified. Full article

(This article belongs to the Special Issue Advanced Materials for Plasmonics, Metamaterials and Metasurfaces)

► Show Figures

Figure 1

13 pages, 2250 KB

Open AccessArticle

Broadband Frequency Selective Rasorber Based on Spoof Surface Plasmon Polaritons

by Jin Bai, Qingzhen Yang, Yichao Liang and Xiang Gao

Micromachines 2022, 13(11), 1969; https://doi.org/10.3390/mi13111969 - 13 Nov 2022

Cited by 12 | Viewed by 2775

Abstract

A broadband frequency selective rasorber (FSR) based on spoofsurface plasmon polaritons (SSPP) is proposed. The FSR is composed of a multi-layer structure comprising frequency selective surface (FSS)-polyresin (PR)-indium tin oxide (ITO)-PR-FSS and placed vertically on a metal base plate. A periodic square cavity [...] Read more.

A broadband frequency selective rasorber (FSR) based on spoofsurface plasmon polaritons (SSPP) is proposed. The FSR is composed of a multi-layer structure comprising frequency selective surface (FSS)-polyresin (PR)-indium tin oxide (ITO)-PR-FSS and placed vertically on a metal base plate. A periodic square cavity structure is formed. The transmission characteristics of the FSR are studied by full-wave simulation and equivalent circuit method. The simulation results demonstrate that under normal incidence, the absorption rate of the structure remains 95% in the 5–30 GHz band, and the absorption rate is also 80% in the 3.5–5 GHz band. As the incident angle of the electromagnetic wave increases to 40°, the absorption rate in the 15–20 GHz band decreases to 70% in the transverse electric (TE) mode, and the absorption rate in the transverse magnetic (TM) mode is almost the same as that of vertical incidence. The transmission response of the structure is measured in an anechoic chamber. The measurement results agree well with the simulation results, proving the reliability of the design and fabrication. The structure is less sensitive to the incident angle of magnetic waves and has a better broadband absorbing ability. Full article

(This article belongs to the Special Issue Advanced Interconnect and Packaging)

► Show Figures

Figure 1

10 pages, 31943 KB

Open AccessArticle

Broadband-Transmissive, Frequency-Selective Rasorber Design Using Characteristic Mode Analysis

by Jie Xiong, Baoping Yang, Yanjie Wu, Xiongwei Zeng, Qiuyu Li, Rongxin Tang and Hai Lin

Electronics 2022, 11(9), 1418; https://doi.org/10.3390/electronics11091418 - 28 Apr 2022

Cited by 12 | Viewed by 4333

Abstract

This article designs a frequency-selective rasorber (FSR) with a broadband transmission window. It is synthesized by a broadband absorber and a frequency-selective surface (FSS). The resistive layer achieves broadband absorption by introducing a tortuous Jerusalem cross load with lumped resistors, and the lossless [...] Read more.

This article designs a frequency-selective rasorber (FSR) with a broadband transmission window. It is synthesized by a broadband absorber and a frequency-selective surface (FSS). The resistive layer achieves broadband absorption by introducing a tortuous Jerusalem cross load with lumped resistors, and the lossless FSS adopts a three-layer metal structure to realize the broadband transmission window. The absorption mechanism of the resistive layer is analyzed using the theory of characteristic mode. The position of the resistor is determined according to the analysis of mode current distribution and parameter optimization. Prototypes of the structure were fabricated and measured, and the simulation results show that the 1 dB transmission window and the absorption band with

| S 11 | <

−1 dB are 36.4% and 97%, respectively. Therefore, the designed FSR has potential application prospects in electromagnetic stealth technology and radar cross-section reduction. Full article

(This article belongs to the Special Issue Metasurfaces Applications in Antennas and Microwave Devices)

► Show Figures

Figure 1

9 pages, 3995 KB

Open AccessArticle

Novel Frequency-Selective Rasorber with Ultrawide Absorption Bandwidth Covering Both the X- and Ku-Bands

by Jie Xiong, Yanjie Wu, Yu Mao, Feng Deng, Lijie Chen and Hai Lin

Electronics 2020, 9(9), 1449; https://doi.org/10.3390/electronics9091449 - 5 Sep 2020

Cited by 6 | Viewed by 3822

Abstract

A novel dual-polarized transmissive/absorptive frequency-selective rasorber (FSR) with an ultrawide absorption spectrum covering both the X- and Ku-bands is proposed in this paper. The FSR is constructed from a bottom lossless transmission layer and a top lossy absorption layer, in which a resistor-loaded [...] Read more.

A novel dual-polarized transmissive/absorptive frequency-selective rasorber (FSR) with an ultrawide absorption spectrum covering both the X- and Ku-bands is proposed in this paper. The FSR is constructed from a bottom lossless transmission layer and a top lossy absorption layer, in which a resistor-loaded incurved square loop strip line structure is utilized to obtain an ultrawide absorption band. To quantitatively analyze its operation principle, an accurate equivalent circuit model of the proposed FSR was developed. A 2D prototype was designed, assembled, fabricated, and measured. The FSR exhibits an absorption band that ranges from 8.1 to 19.1 GHz (81%) under normal incidence, whereas the passband insertion loss at 4.5 GHz is less than 0.45 dB. The total thickness of the FSR is only 5.1 mm, which keeps low profile characteristics. The simulation agrees well with the measured results. Full article

(This article belongs to the Section Microwave and Wireless Communications)

► Show Figures

Figure 1

Search Results (9)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (9)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI