Abstract

Designing an ultra-wideband metasurface absorber is challenging because of its lossy characteristic that hinders the understanding of its resonance behavior. In this study, a framework was formulated to extend the application of the theory of characteristic modes to the analysis and design of metabsorbers. The metabsorber and its lossless counterpart exhibited similar modal behaviors, hence revealing the absorption mechanism of metabsorber. By introducing absorption modes, a dual-band metabsorber was converted into an ultra-wideband metabsorber. This proposed metabsorber with a thickness of 1.99 times the Rozanov’s limit could measure a bandwidth of 5.51–36.56 GHz (or 6 octaves) with 90% absorptance.

© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

1. Introduction

Absorbers convert the incident electromagnetic energy into heat to reduce scattering [15]. Thin and optically transparent microwave metabsorbers are attractive for applications that require optical transparency, microwave absorption and a low profile simultaneously, such as radio-frequency identification systems, anechoic chambers and industrial manufacturing [610]. However, it is challenging to meet the requirements of low profile and large bandwidth simultaneously.

Although optimization algorithms are effective, optimization-based methods such as genetic algorithm and particle swarm optimization are usually both high time and power consuming processes [1115]. Moreover, it may be difficult to attain the fabrication tolerance required by machine-optimized designs [1618]. Most importantly, the difficulties associated with the understanding of the underlying physics of such optimized structures impede the development of general rules or ideas for further optimizations of the bandwidth and thickness. On the other hand, the equivalent circuit method, in which a metasurface is modeled by an equivalent circuit containing L–R–C resonators, can effectively improve the bandwidth of metabsorbers [1923]. However, a variety of equivalent circuit models are required owing to the large range in electrical sizes of the absorber under wideband conditions; further, its design is troublesome. For irregular shapes, it is difficult to extract equivalent circuit parameters. Therefore, new methods are needed for designing low-profile wideband absorbers.

Metasurfaces are widely used to improve the absorption performance of absorbers. The theory of characteristic modes (TCM), originally proposed for perfect electrical conductors (PECs) and wire antennas, has been recently demonstrated to be a powerful tool for designing metasurface antennas [2428]. Although some valuable attempts have been made in the TCM formulations for lossy dielectric bodies [2932], the formulations are not applicable for lossy sheets of infinitesimal thicknesses. As a result, the application of TCM to metabsorbers is limited to the analysis of the lossless counterpart of the metabsorber without including the loss in lossy sheet [3335], where excitations are not considered; hence, the connection between the modes introduced by the lossless resonator and those by the lossy absorber is missing. For a meta-resonator with a significant number of modes, it is crucial to obtain information on the excited modes in addition to the existing modes to understand the underlying absorption physics and perform effective optimization.

In this study, an alternate method based on the characteristic mode formulation for lossless sheets was used to analyze the absorption performance of metabsorber using lossy sheets under planewave illumination. This developed approximation method was formulated to extend the application of TCM to the analysis and design of metabsorbers. The electric field (E-field) distribution as well as the absorption and scattering powers of the metabsorber and its lossless counterpart were found to be similar, and thus, both of them exhibited similar modal behavior. The approximation method was used to analyze a patch-type metabsorber using the characteristic mode, and it was found that the excitation of absorption modes caused the absorption phenomenon. For proof-of-concept, the patch-type metabsorber exhibiting dual-band absorption was converted into an ultra-wideband metabsorber by introducing additional modes. All the simulations were performed using CST Studio Suite 2020 [36]. Finally, the simulated results were verified through experiments to support the feasibility of the proposed method.

2. Designs and analysis

2.1 Theory of characteristic mode

The TCM, first proposed in 1965 [37], can be applied to PECs, dielectrics and magnetic materials [24,3840]. The characteristics mode formulation can be applied to different surfaces and interfaces using different integral equations, which can be solved by converting them into a matrix equation using the method of moments.

The characteristic mode analysis (CMA) is a simple and easy method to understand the physics behind many key factors of radiation and scattering problems. By solving a generalized eigenvalue equation: X Jn= λn R Jn, the eigenvectors Jn and eigenvalues λn are obtained, where n is the index of each mode order, R and X are the real and imaginary Hermitian parts of the impedance matrix Z = R + jX [41]. The eigenvalues λn can be transformed to the modal significance given by: MS = |1 / (1 + jλn)| with a smaller range of [0,1]; the MS is a more convenient parameter for investigating the resonance behavior in wideband. The current J induced on a PEC under an impressed E-field can be decomposed as: J = ∑ αn Jn, where |αn| or the magnitude of the modal weighting coefficients (MWC) represent the contribution of each Jn to the total radiated power Prad as Prad = Σ|MWC|2.

2.2 Material and boundary approximations

Because the TCM is not applicable for lossy sheets of infinitesimal thickness, it cannot be applied to metabsorbers that use lossy sheets. However, the similarity of energy conversion between the lossless and lossy structures makes it possible to analyze the metabsorber using TCM. Figure 1 illustrates the energy conversion by ideal lossless and lossy structures under planewave illumination. In a lossless structure, the induced current scatters the incident energy into space, whereas in a lossy structure, the induced current converts the incident energy into resistive heat. Notably, the energy conversion by a structure with or without loss occurs through scattering and absorption caused by the induced current. According to the energy conservation law, the energy absorbed by a lossy structure is equal to that scattered by its lossless counterpart. In contrast, in an actual absorber, along with the absorption, a small fraction of the incident energy is scattered as well; however, this scattered wave has a negligible effect on the equivalence relationship. Therefore, the TCM can be applied to evaluate a metabsorber by analyzing its lossless counterpart.

 figure: Fig. 1.

Fig. 1. Energy conversion by the (a) lossless structure (ideal case of scattering), (b) lossy structure (ideal case of absorption) and (c) lossy structure (actual case of coexistence of scattering and absorption).

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Based on the aforementioned analysis, we propose the method of material and boundary approximation to analyze the modal behavior of a metabsorber through its lossless counterpart. A conventional patch-type metabsorber, whose configuration is shown in Fig. 2, was used for the comparing the results obtained by the proposed approximation method. The metabsorber consisted of two layers: a patch layer of periodic square patch resonators each with a width of L1 = 12 mm and a ground layer of a continuous film; both the layers were made of an indium tin oxide (ITO), which was sputtered on polyethylene terephthalate (PET) substrates (thickness, dpet = 0.125 mm, relative permittivity: 2.65 and loss tangent: 0.015) to form a ground layer with a sheet resistance of 6Ω/sq and a patch layer with a sheet resistance of 160 Ω/sq. For the unit cell, the width of the lattice was P = 18 mm, and the thickness of the air gap was dair = 6.125 mm.

 figure: Fig. 2.

Fig. 2. Schematics of the patch-type metabsorber array and its unit cell configuration.

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The approximation method is valid when the metabsorber and its counterpart have similar E-field responses under planewave illumination. Hence, the E-field distribution comparisons are made below and above the patch, where the peak and null of the E-field are of interest. The comparisons of the E-field distributions for the approximations are shown in Table 1. In both the approximations, normal planewave irradiation is considered. The lossy sheet and its periodic boundary are approximated by the lossless sheet and absorbing boundary, respectively. Notably, the approximation of the material is for the patch and ground layers made of ITO. In addition, a coordinate system with origin at the center of the unit cell is used throughout the calculations.

Tables Icon

Table 1. Summary of E-field distribution comparisons for approximations

The material approximation is built by approximating the lossy sheet with a lossless sheet. The E-field distributions exhibited by the structures with lossy and lossless sheets are similar when a periodic boundary is used. Figure 3(a) and 3(b) show the E-field distributions below the patch. Evidently, the tangential E-field reaches a maximum at both ends of the patch, whereas a low amplitude appears at y = 0 (below the patch). The “hips-like” structure of the E-field distribution indicates the presence of TMx001 mode below the patch, implying that the mode behavior below the patch layer does not show any significant change when the material is changed from lossy to lossless sheet. Figure 3(d) and 3(e) depict the E-field distribution above the patch. Evidently, the maximum field is in the x-direction in this case, and the field at x = 6 is selected for a detailed comparison as demonstrated in Fig. 4(a). The two E-field-amplitude curves corresponding to the lossy and lossless sheets exhibit good fitting at the extrema and show a relative trend of the E-field. Thus, the mode behavior above the patch layer does not show any significant change upon changing the material. These results imply that replacing the lossy sheet of the metabsorber with a lossless sheet does not affect the spatial E-field distribution.

 figure: Fig. 3.

Fig. 3. E-field distribution produced by a 6 GHz wave at x = 0 mm for: (a) lossy sheet with periodic boundary; (b) lossless sheet with periodic boundary and (c) lossless sheet with absorbing boundary. E-field distribution produced by a 6 GHz wave at z = 6.5 mm for: (d) lossy sheet with periodic boundary; (e) lossless sheet with periodic boundary and (f) lossless sheet with absorbing boundary.

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 figure: Fig. 4.

Fig. 4. Comparisons of E-field amplitudes produced by a 6 GHz wave at z = 6.5 mm and x = 6 mm: (a) between lossy sheet and lossless sheet and (b) between periodic and absorbing boundaries.

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Next, we formulate the boundary approximation by approximating an infinite periodic boundary with a finite absorbing boundary. Similar E-field distributions are obtained under the two boundaries when a lossless sheet is used in both the structures. Figure 3(b) and 3(c) show the E-field distributions below the patch. The polarization of the field and the location where the extreme value occurs remain similar. Figure 3(e) and 3(f) show the similarity of the E-field distributions above the patch, and a detailed comparison is presented in Fig. 4(b), which further establishes the similarity in the field distribution. Based on these results, it can be considered that a periodic boundary can be approximated with a finite absorbing boundary. Therefore, similar E-field responses are obtained under the material and boundary approximations, and hence, the CMA can be used to analyze a metabsorber through the approximation method.

2.3 Analysis and design based on CMA

The CMA results of the patch-type metabsorber were calculated and analyzed using the CMA tools and the proposed approximation method. Because the loss of substrates produces a negligible effect on the total absorption, the loss tangent of PET substrate was not considered in the calculations. The ground layer and substrates were extended infinitely; the metabsorber unit cells were extended infinitely in the x-y direction to simulate the absorption, which can be calculated by: A = 1 – R– T, where R = |S11|2 and T = |S21|2 are the reflectance and transmittance derived from the S-parameter, respectively.

Figure 5 shows a comparison between the scattering power of the lossless counterpart, represented by Σ|MWC|2, and the absorbing power of the patch-type metabsorber. The metabsorber based on the ITO patch resonator (sheet resistance: 160 Ω/sq) achieves dual-band absorption in the ranges of 6.8–15.9 and 30.6–37.1 GHz (absorption > 0.9). The absorbing power of the metabsorber and the scattering power of the reactive counterpart showed similar trends. In addition, the minimum was observed at 23.5 GHz, and the two observed wideband peaks resemble each other. Furthermore, when we adjust the surface resistance of the patch, the magnitude of the absorption changes; however, the position of the absorption peak band is always roughly consistent with that of the scattering peak band. Thus, the absorption power of the patch-type metabsorber is similar to the scattering power (Σ|MWC|2) of the lossless counterpart.

 figure: Fig. 5.

Fig. 5. Comparison between the absorption power and scattering power (Σ|MWC|2) of the patch-type metabsorber.

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To reveal the dual-band absorption mechanism of the patch-type metabsorber, the CMA results are analyzed at the absorption peaks and absorption minimums at 9, 34, and 23.5 GHz. Since |MWC|2 measures the contribution of each mode to the total power, the excited modes are arranged in descending order of |MWC|2, shown in Fig. 6. Normalization is performed by defining the |MWC|2 maximum as 1 at each frequency. Although the structure of metabsorber has a significant number of modes, only a few of them are excited. As can be seen, the excited single-dominant mode, mode 12 and mode 29 appear at 9 GHz and 23.5 GHz, respectively. In this scenario, the normalized |MWC|2 of mode 12 and mode 29 are much higher than that of other modes, hence the modal behavior of the single-dominate mode is consistent with that of the metabsorber. Unlike other frequencies, three dominant modes are excited at 34 GHz, as shown in Fig. 6(c).

 figure: Fig. 6.

Fig. 6. Normalized |MWC|2 for the patch-type metabsorber at (a) 9 GHz, (b) 23.5 GHz and (c) 34 GHz.

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The consistency between the radiation and absorption patterns becomes evident with the extended application of the reciprocity theorem [42]. Therefore, the mode radiation pattern can be used to analyze the absorption performance. Accordingly, the modal radiation patterns of the dominant modes are calculated and plotted in Fig. 7. As shown in Fig. 7(a), the dominant mode—mode 12—generates broadside radiation at 9 GHz, whereas the other modal patterns generate a lower magnitude of the E-field in the + z direction with a lower value of |MWC|2, as shown in Fig. 7(b) and 7(c). In addition, at the other absorption peak, the three excited dominant modes generate similar broadside radiation, as shown in Fig. 7(h)–7(j). Conversely, a radiation null appears at the broadside of the frequency of the absorption minimum, as shown in Fig. 7(d). Consequently, when the planewave is normally incident on the counterpart of the metabsorber, only the modal currents that generate broadside radiation are excited. According to Joule’s law, the dominant modal currents flowing on the lossy sheet of the metabsorber cause absorption. Thus, under normal planewave irradiation, the excited dominant modes can be called as normal absorption modes (hereafter, referred to as absorption modes). The CMA results indicated that the absorption was caused by the occurrence of absorption modes.

 figure: Fig. 7.

Fig. 7. Modal radiation patterns of the patch-type metabsorber: (a–c) modes 12, 15, and 8 at 9 GHz, respectively; (d–f) modes 29, 3, and 8 at 23.5 GHz, respectively; (h–j) modes 30, 14, and 10 at 34 GHz, respectively.

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The CMA results showed that it is difficult for the conventional patch-type metabsorber to achieve ultra-wideband absorption because of the lack of absorption modes. To the best of our knowledge, additional absorption modes can be excited by inserting additional resonators. Thus, the CMA-based method for wideband optimization can be summarized in the following three steps:

  • 1. Replace the lossy sheet and periodic boundary of the metabsorber array with a lossless sheet and absorbing boundary. Hence, the lossless counterpart of the metabsorber can be analyzed using TCM.
  • 2. Calculate Σ|MWC|2 of the metabsorber under normally incident planewave, and find the frequency band in which no dominant modes (absorption modes) are excited.
  • 3. Insert additional resonators to introduce absorption modes in the corresponding frequency band to achieve ultra-wideband absorption optimization.

As a proof-of-concept design, the ring resonator is inserted into the patch-type metabsorber, and an absorption mode is introduced to achieve ultra-wideband optimization. The metabsorber and layer designs are illustrated in Fig. 8. The detailed parameter configurations are: P = 18 mm, L1 = 12 mm, L2 = 3 mm, dup = 2.5 mm and dlow = 3.5 mm. For the ITO sheets on the substrates, the sheet resistance of the ground layer was R1 = 6 Ω/sq and that of the remaining layers was R2 = 160 Ω/sq. Figure 9 shows Σ|MWC|2 of the metabsorbers with patch (denoted by MA-A) and ring resonators (denoted by MA-B). Evidently, the Σ|MWC|2 peak of MA-B appears in the range of 18–28 GHz, indicating the appearance of the absorption mode; the absorption null of MA-A also appears in the same band. Therefore, it is possible to introduce additional absorption modes around 20 GHz by inserting the ring resonator of MA-B into MA-A for achieving ultra-wideband absorption. The geometrical model of the proposed full metabsorber (denoted by MA-C) and its absorption value are shown in Fig. 8(c) and Fig. 9, respectively. The proposed metabsorber achieves over 90% absorption in the range of 5.51–36.56 GHz. The three absorption peaks roughly correspond to the peaks of Σ|MWC|2. This indicates that the absorption modes of MA-A and MA-B appear in MA-C, which, in turn, achieves ultra-wideband absorption.

 figure: Fig. 8.

Fig. 8. Geometrical modelling of the three metabsorbers and the patch and ground layers: (a) patch-type metabsorber (MA-A); (b) ring-type metabsorber (MA-B); (c) full metabsorber (MA-C); (d) patch layer; (e) ring layer and (f) ground layer.

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 figure: Fig. 9.

Fig. 9. Absorption of the full metabsorber (MA-C). Σ|MWC|2 values of the patch-type (MA-A) and ring-type (MA-B) metabsorbers.

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To verify the introduced absorption modes, the modal behavior of the ring resonator with and without the influence of the patch resonator is elaborated here. The |MWC|2 values are shown in Fig. 10(a) and 10(d), which show that a similar single dominant mode was excited in both the metabsorbers. In addition, the modal radiation patterns of the dominant modes are plotted for comparison in Fig. 10(b) and 10(e). Similar strong E-fields in the + z direction are obtained in both the metabsorbers, despite the differences in the minor lobes. For further confirmation, the modal currents of the dominant mode in the ring resonator are compared, as shown in Fig. 10(c) and 10(f); the peak and direction of the modal currents are of interest in this case. An upward current is generated on the left and right sides of the ring, whereas a downward current is generated on the upper and lower sides. These results demonstrate that the absorption mode of the ring resonator remains almost unchanged with or without the influence of the patch layer. This proves that ultra-wideband absorption can be achieved by introducing absorption modes into the metabsorber.

 figure: Fig. 10.

Fig. 10. The normalized |MWC|2 for (a) MA-B (ring-type metabsorber) and (d) MA-C (full metabsorber) at 23.5 GHz, and the modal radiation patterns for (b) MA-B and (e) MA-C generated by the modal current J5 and J7 on the ring layer of (c) MA-B and (f) MA-C, respectively.

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The above-mentioned analysis and optimization indicate that Σ|MWC|2 can be used to predict the potential absorption performance of a metabsorber because it represents the total contribution of the absorption modes. Furthermore, an additional absorption mode can be introduced by inserting meta-resonators for ultra-wideband optimization. Most importantly, the CMA results provide physical insights into the absorption phenomenon as well as aid in developing insightful guidelines for the ultra-wideband optimization of the metabsorber.

3. Performance characterization

3.1 Simulating performance characterization

In addition to the wideband absorption characteristic, it is necessary for the proposed absorbers to be thin and possess angular stability for practical applications. To evaluate the thickness of the proposed absorber, the ratio of the metabsorber’s thickness to Rozanov’s limit was compared. Rozanov’s limit of the wideband absorber can be calculated as:

$$\left|{\int_0^\infty {\ln } |{\mathrm{\rho }{(\lambda )}} |\textrm{d}\mathrm{\lambda }} \right|\le \textrm{2}{\mathrm{\pi }^\textrm{2}}{\mathrm{\mu}_\textrm{s}}\textrm{d}$$
where λ is the wavelength, ρ(λ) is the complex reflection coefficient of complex wavelengths, μs is the static permeability, and d is the thickness of the absorber [43]. Because the material of the transparent metabsorber is nonmagnetic (μs ≡ 1), Eq. (1) can be simplified to
$${\Gamma _0}({\mathrm{\lambda }_{\textrm{max}}}\textrm{ - }{\mathrm{\lambda }_{\textrm{min}}}) \le 40{\mathrm{\pi }^\textrm{2}}\textrm{d / ln10} \approx 172\textrm{d}$$
where the reflectance Γ0 is expressed as: Γ0 = 20log (ρ0), and λmin and λmax are the maximum and minimum wavelengths of the frequency range for Γ0 reflectance, respectively. Equation (2) shows that the Rozanov’s limit is (λmax – λmin)/17.2 for the metabsorber exhibiting 10 dB reflectance (90% absorption). For comparison, the ratio of the metabsorber thickness to Rozanov’s limit is listed in Table 2. As can be seen, the proposed absorber achieves a wider absorption bandwidth with a similar thickness.

Tables Icon

Table 2. Comparison with other transparent wideband metabsorbers

To evaluate the angular stability, the absorptance of MA-C under the TE and TM modes of obliquely incident planewave was simulated as shown in Fig. 11. Evidently, under TE mode incidence, the absorption is almost 90% at incident angles of 0°–25°, except at 27 GHz under which the absorption shows a decreasing trend. Under the TM modes, the absorption exhibits a slow blue shift as the incident angle increases, and the angular stability improves. Overall, the absorptivity of the metamaterial absorber is above 80% at incident angles of 0°–40° under both the TM and TE mode incidence across the working bandwidth, which spans the entire X-, Ku- and K-bands. These results establish the practical applicability of the proposed absorber.

 figure: Fig. 11.

Fig. 11. Simulated absorptivity as a function of incidence angle, for (a) TE and (b) TM polarizations.

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3.2 Experimental performance characterization

The absorption performance of the proposed MA-C metabsorber was experimentally verified as well. A square array of 16 × 16 unit cells with an overall width of 288 mm was fabricated, as shown in the inset of Fig. 12(b). The patch and ring resonators were developed by laser etching a uniform ITO sheet with a sheet resistance of 155 Ω/sq (the proposed value is 160 Ω/sq). Another ITO sheet with a sheet resistance of 6 Ω/sq was used as the ground layer. Two commercial polymethyl methacrylate (PMMA) frames with average thicknesses of 2.47 and 3.58 mm were used as supports for the upper and lower air gaps, respectively. The three layers were glued to frames with an optically transparent adhesive to fabricate air gaps with specific thicknesses. However, the optical adhesive and frames produced a slight thickness error owing to which the MA-C sample thickness was found to be dup = 2.48 mm and dlow = 4.1 mm (the proposed is dup = 2.5 mm and dlow = 3.5 mm).

 figure: Fig. 12.

Fig. 12. Schematics of the experimental setup for measuring the reflectance of MA-C and comparison between the measured and simulated absorptions of MA-C. Inset shows photograph of the fabricated metabsorber sample.

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Figure 12(a) shows the setup for the measurement of the reflectance at normal incidence. Owing to the excellent shielding performance of the ground layer, the transmittance was ignored. The measured absorption, which is defined by A = 1 – |S11|2, showed that the absorptance was above 90% over the frequency ranges of 5–9.95 and 19–36.06 GHz. As the fabricated sample had different parameters, the simulation was performed again to compare the resulting values. Evidently, the trend and the frequencies of the simulated and measured maxima were approximately similar to each other, although a difference was observed in the minimum at approximately 15 GHz. The error in the minimum was possibly caused by: (1) the larger size of the normalized metal plate, which had a width of 300 mm; (2) inconsistency in the measured thicknesses caused by slight sagging of the layers; (3) inclusion of PMMA frame; (4) resonance in the actual finite structure; and (5) inhomogeneity of the ITO sheet. In summary, the appearance of the three resonant peaks demonstrated the effectiveness of introducing absorption modes for wideband optimization and provided insights into the physics of the excited modes of the meta-resonators.

4. Conclusion

In this study, we extended TCM to the analysis and design of lossy absorbers. By comparing the vector E-field distributions as well as the absorption and scattering powers of the same meta-resonators with and without loss, a connection was built between the resonant modes of the metabsorbers and their counterparts. With the absorption physics clearly revealed, additional absorption modes were introduced to improve the bandwidth of the conventional patch-type metabsorber significantly, thereby forming the proposed optically transparent metabsorber that simultaneously exhibited ultra-wideband absorption characteristic and a low profile. Furthermore, the proposed structure exhibited a wider absorption bandwidth than did the previously reported transparent wideband metabsorbers with similar thicknesses. The proposed analysis and design framework paves the way for the physics-oriented optimization of absorbers with the aid of CMA.

Funding

National Natural Science Foundation for Distinguished Young Scholars of China (51625201); Key Project of National Natural Science Foundation of China (52032004); Shanghai Pujiang Program (20PJ1411400).

Disclosures

The authors declare no conflicts of interest.

Data availability

Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.

References

1. E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section (SciTech Publishing, 2004), Chap. 8.

2. W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018). [CrossRef]  

3. N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008). [CrossRef]  

4. Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015). [CrossRef]  

5. L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018). [CrossRef]  

6. K. Chen, L. Cui, Y. Feng, J. Zhao, T. Jiang, and B. Zhu, “Coding metasurface for broadband microwave scattering reduction with optical transparency,” Opt. Express 25(5), 5571–5579 (2017). [CrossRef]  

7. P. P. Min, Z. C. Song, L. Yang, B. Dai, and J. Q. Zhu, “Transparent ultrawideband absorber based on simple patterned resistive metasurface with three resonant modes,” Opt. Express 28(13), 19518–19530 (2020). [CrossRef]  

8. Y. Okano, S. Ogino, and K. Ishikawa, “Development of optically transparent ultrathin microwave absorber for ultrahigh-frequency RF identification system,” IEEE Trans. Microwave Theory Tech. 60(8), 2456–2464 (2012). [CrossRef]  

9. C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017). [CrossRef]  

10. Y. Zhang, H. Dong, N. Mou, L. Chen, R. Li, and L. Zhang, “High-performance broadband electromagnetic interference shielding optical window based on a metamaterial absorber,” Opt. Express 28(18), 26836–26849 (2020). [CrossRef]  

11. P. Y. Chen, C. H. Chen, H. Wang, J. H. Tsai, and W. X. Ni, “Synthesis design of artificial magnetic metamaterials using a genetic algorithm,” Opt. Express 16(17), 12806–12818 (2008). [CrossRef]  

12. T. Li, K. Chen, G. Ding, J. Zhao, T. Jiang, and Y. Feng, “Optically transparent metasurface Salisbury screen with wideband microwave absorption,” Opt. Express 26(26), 34384–34395 (2018). [CrossRef]  

13. S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018). [CrossRef]  

14. Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019). [CrossRef]  

15. J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018). [CrossRef]  

16. S. Chakravarty, R. Mittra, and N. R. Williams, “On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media,” IEEE Trans. Microwave Theory Tech. 49(6), 1050–1059 (2001). [CrossRef]  

17. G. Manara, A. Monorchio, and R. Mittra, “Frequency selective surface design based on genetic algorithm,” Electron. Lett. 35(17), 1400–1401 (1999). [CrossRef]  

18. M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004). [CrossRef]  

19. R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019). [CrossRef]  

20. D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017). [CrossRef]  

21. H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017). [CrossRef]  

22. H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019). [CrossRef]  

23. Y. Zheng, K. Chen, T. Jiang, J. Zhao, and Y. Feng, “Multi-octave microwave absorption via conformal metamaterial absorber with optical transparency,” J. Phys. D: Appl. Phys. 52(33), 335101 (2019). [CrossRef]  

24. R. F. Harrington and J. R. Mautz, “Theory of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 622–628 (1971). [CrossRef]  

25. F. H. Lin and Z. N. Chen, “Low-profile wideband metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 65(4), 1706–1713 (2017). [CrossRef]  

26. F. H. Lin and Z. N. Chen, “Truncated impedance sheet model for low-profile broadband nonresonant-cell metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(10), 5043–5051 (2018). [CrossRef]  

27. F. H. Lin and Z. N. Chen, “A method of suppressing higher order modes for improving radiation performance of metasurface multiport antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(4), 1894–1902 (2018). [CrossRef]  

28. F. H. Lin and Z. N. Chen, “Resonant metasurface antennas with resonant apertures: Characteristic mode analysis and dual-polarized broadband low-profile design,” IEEE Trans. Antennas Propag. 69(6), 3512–3516 (2021). [CrossRef]  

29. S. Ghosal, A. De, R. M. Shubair, and A. Chakrabarty, “Vertical dipole above the lossy dielectric half-space—A characteristic mode analysis,” IEEE Trans. Electromagn. Compat. 62(6), 2832–2841 (2020). [CrossRef]  

30. P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019). [CrossRef]  

31. P. Yla-Oijala, H. Wallén, and S. Järvenpää, “Theory of characteristic modes for lossy structures: Formulation and interpretation of eigenvalues,” Int. J. Numer. Model. 33(2), e2627 (2020). [CrossRef]  

32. P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018). [CrossRef]  

33. Q. Guo, J. Su, and Z. Li, “Design of circuit analog absorber using characteristic mode analysis,” in IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) (2020), pp. 1–3.

34. D. Zha, J. Dong, Z. Cao, Y. Zhang, F. He, R. Li, Y. He, L. Miao, S. Bie, and J. Jiang, “A multimode, broadband and all-inkjet-printed absorber using characteristic mode analysis,” Opt. Express 28(6), 8609–8618 (2020). [CrossRef]  

35. Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021). [CrossRef]  

36. CST Computer Simulation Technology. (2020) CST MWS. http://www.cst.com.

37. R. J. Garbacz, “Modal expansions for resonance scattering phenomena,” Proc. IEEE 53(8), 856–864 (1965). [CrossRef]  

38. R. F. Harrington and J. R. Mautz, “Computation of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 629–639 (1971). [CrossRef]  

39. R. F. Harrington, J. R. Mautz, and Y. Chang, “Characteristic modes for dielectric and magnetic bodies,” IEEE Trans. Antennas Propag. 20(2), 194–198 (1972). [CrossRef]  

40. Y. Chang and R. F. Harrington, “A surface formulation for characteristic modes of material bodies,” IEEE Trans. Antennas Propag. 25(6), 789–795 (1977). [CrossRef]  

41. Y. Chen and C. Wang, Characteristics Modes Theory and Applications in Antenna Engineering (Wiley Publishing, 2015), Chap. 2.

42. T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

43. K. N. Rozanov, “Ultimate thickness to bandwidth ratio of radar absorbers,” IEEE Trans. Antennas Propag. 48(8), 1230–1234 (2000). [CrossRef]  

References

  • View by:

  1. E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section (SciTech Publishing, 2004), Chap. 8.
  2. W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
    [Crossref]
  3. N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
    [Crossref]
  4. Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
    [Crossref]
  5. L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018).
    [Crossref]
  6. K. Chen, L. Cui, Y. Feng, J. Zhao, T. Jiang, and B. Zhu, “Coding metasurface for broadband microwave scattering reduction with optical transparency,” Opt. Express 25(5), 5571–5579 (2017).
    [Crossref]
  7. P. P. Min, Z. C. Song, L. Yang, B. Dai, and J. Q. Zhu, “Transparent ultrawideband absorber based on simple patterned resistive metasurface with three resonant modes,” Opt. Express 28(13), 19518–19530 (2020).
    [Crossref]
  8. Y. Okano, S. Ogino, and K. Ishikawa, “Development of optically transparent ultrathin microwave absorber for ultrahigh-frequency RF identification system,” IEEE Trans. Microwave Theory Tech. 60(8), 2456–2464 (2012).
    [Crossref]
  9. C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
    [Crossref]
  10. Y. Zhang, H. Dong, N. Mou, L. Chen, R. Li, and L. Zhang, “High-performance broadband electromagnetic interference shielding optical window based on a metamaterial absorber,” Opt. Express 28(18), 26836–26849 (2020).
    [Crossref]
  11. P. Y. Chen, C. H. Chen, H. Wang, J. H. Tsai, and W. X. Ni, “Synthesis design of artificial magnetic metamaterials using a genetic algorithm,” Opt. Express 16(17), 12806–12818 (2008).
    [Crossref]
  12. T. Li, K. Chen, G. Ding, J. Zhao, T. Jiang, and Y. Feng, “Optically transparent metasurface Salisbury screen with wideband microwave absorption,” Opt. Express 26(26), 34384–34395 (2018).
    [Crossref]
  13. S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
    [Crossref]
  14. Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
    [Crossref]
  15. J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
    [Crossref]
  16. S. Chakravarty, R. Mittra, and N. R. Williams, “On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media,” IEEE Trans. Microwave Theory Tech. 49(6), 1050–1059 (2001).
    [Crossref]
  17. G. Manara, A. Monorchio, and R. Mittra, “Frequency selective surface design based on genetic algorithm,” Electron. Lett. 35(17), 1400–1401 (1999).
    [Crossref]
  18. M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004).
    [Crossref]
  19. R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
    [Crossref]
  20. D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
    [Crossref]
  21. H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
    [Crossref]
  22. H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
    [Crossref]
  23. Y. Zheng, K. Chen, T. Jiang, J. Zhao, and Y. Feng, “Multi-octave microwave absorption via conformal metamaterial absorber with optical transparency,” J. Phys. D: Appl. Phys. 52(33), 335101 (2019).
    [Crossref]
  24. R. F. Harrington and J. R. Mautz, “Theory of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 622–628 (1971).
    [Crossref]
  25. F. H. Lin and Z. N. Chen, “Low-profile wideband metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 65(4), 1706–1713 (2017).
    [Crossref]
  26. F. H. Lin and Z. N. Chen, “Truncated impedance sheet model for low-profile broadband nonresonant-cell metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(10), 5043–5051 (2018).
    [Crossref]
  27. F. H. Lin and Z. N. Chen, “A method of suppressing higher order modes for improving radiation performance of metasurface multiport antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(4), 1894–1902 (2018).
    [Crossref]
  28. F. H. Lin and Z. N. Chen, “Resonant metasurface antennas with resonant apertures: Characteristic mode analysis and dual-polarized broadband low-profile design,” IEEE Trans. Antennas Propag. 69(6), 3512–3516 (2021).
    [Crossref]
  29. S. Ghosal, A. De, R. M. Shubair, and A. Chakrabarty, “Vertical dipole above the lossy dielectric half-space—A characteristic mode analysis,” IEEE Trans. Electromagn. Compat. 62(6), 2832–2841 (2020).
    [Crossref]
  30. P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019).
    [Crossref]
  31. P. Yla-Oijala, H. Wallén, and S. Järvenpää, “Theory of characteristic modes for lossy structures: Formulation and interpretation of eigenvalues,” Int. J. Numer. Model. 33(2), e2627 (2020).
    [Crossref]
  32. P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018).
    [Crossref]
  33. Q. Guo, J. Su, and Z. Li, “Design of circuit analog absorber using characteristic mode analysis,” in IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) (2020), pp. 1–3.
  34. D. Zha, J. Dong, Z. Cao, Y. Zhang, F. He, R. Li, Y. He, L. Miao, S. Bie, and J. Jiang, “A multimode, broadband and all-inkjet-printed absorber using characteristic mode analysis,” Opt. Express 28(6), 8609–8618 (2020).
    [Crossref]
  35. Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
    [Crossref]
  36. CST Computer Simulation Technology. (2020) CST MWS. http://www.cst.com .
  37. R. J. Garbacz, “Modal expansions for resonance scattering phenomena,” Proc. IEEE 53(8), 856–864 (1965).
    [Crossref]
  38. R. F. Harrington and J. R. Mautz, “Computation of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 629–639 (1971).
    [Crossref]
  39. R. F. Harrington, J. R. Mautz, and Y. Chang, “Characteristic modes for dielectric and magnetic bodies,” IEEE Trans. Antennas Propag. 20(2), 194–198 (1972).
    [Crossref]
  40. Y. Chang and R. F. Harrington, “A surface formulation for characteristic modes of material bodies,” IEEE Trans. Antennas Propag. 25(6), 789–795 (1977).
    [Crossref]
  41. Y. Chen and C. Wang, Characteristics Modes Theory and Applications in Antenna Engineering (Wiley Publishing, 2015), Chap. 2.
  42. T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).
  43. K. N. Rozanov, “Ultimate thickness to bandwidth ratio of radar absorbers,” IEEE Trans. Antennas Propag. 48(8), 1230–1234 (2000).
    [Crossref]

2021 (2)

F. H. Lin and Z. N. Chen, “Resonant metasurface antennas with resonant apertures: Characteristic mode analysis and dual-polarized broadband low-profile design,” IEEE Trans. Antennas Propag. 69(6), 3512–3516 (2021).
[Crossref]

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

2020 (5)

2019 (5)

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019).
[Crossref]

R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
[Crossref]

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

Y. Zheng, K. Chen, T. Jiang, J. Zhao, and Y. Feng, “Multi-octave microwave absorption via conformal metamaterial absorber with optical transparency,” J. Phys. D: Appl. Phys. 52(33), 335101 (2019).
[Crossref]

2018 (8)

F. H. Lin and Z. N. Chen, “Truncated impedance sheet model for low-profile broadband nonresonant-cell metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(10), 5043–5051 (2018).
[Crossref]

F. H. Lin and Z. N. Chen, “A method of suppressing higher order modes for improving radiation performance of metasurface multiport antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(4), 1894–1902 (2018).
[Crossref]

P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018).
[Crossref]

J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
[Crossref]

T. Li, K. Chen, G. Ding, J. Zhao, T. Jiang, and Y. Feng, “Optically transparent metasurface Salisbury screen with wideband microwave absorption,” Opt. Express 26(26), 34384–34395 (2018).
[Crossref]

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018).
[Crossref]

2017 (5)

K. Chen, L. Cui, Y. Feng, J. Zhao, T. Jiang, and B. Zhu, “Coding metasurface for broadband microwave scattering reduction with optical transparency,” Opt. Express 25(5), 5571–5579 (2017).
[Crossref]

C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
[Crossref]

F. H. Lin and Z. N. Chen, “Low-profile wideband metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 65(4), 1706–1713 (2017).
[Crossref]

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

2015 (1)

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

2012 (1)

Y. Okano, S. Ogino, and K. Ishikawa, “Development of optically transparent ultrathin microwave absorber for ultrahigh-frequency RF identification system,” IEEE Trans. Microwave Theory Tech. 60(8), 2456–2464 (2012).
[Crossref]

2008 (2)

N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
[Crossref]

P. Y. Chen, C. H. Chen, H. Wang, J. H. Tsai, and W. X. Ni, “Synthesis design of artificial magnetic metamaterials using a genetic algorithm,” Opt. Express 16(17), 12806–12818 (2008).
[Crossref]

2004 (1)

M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004).
[Crossref]

2001 (1)

S. Chakravarty, R. Mittra, and N. R. Williams, “On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media,” IEEE Trans. Microwave Theory Tech. 49(6), 1050–1059 (2001).
[Crossref]

2000 (1)

K. N. Rozanov, “Ultimate thickness to bandwidth ratio of radar absorbers,” IEEE Trans. Antennas Propag. 48(8), 1230–1234 (2000).
[Crossref]

1999 (1)

G. Manara, A. Monorchio, and R. Mittra, “Frequency selective surface design based on genetic algorithm,” Electron. Lett. 35(17), 1400–1401 (1999).
[Crossref]

1977 (1)

Y. Chang and R. F. Harrington, “A surface formulation for characteristic modes of material bodies,” IEEE Trans. Antennas Propag. 25(6), 789–795 (1977).
[Crossref]

1972 (1)

R. F. Harrington, J. R. Mautz, and Y. Chang, “Characteristic modes for dielectric and magnetic bodies,” IEEE Trans. Antennas Propag. 20(2), 194–198 (1972).
[Crossref]

1971 (2)

R. F. Harrington and J. R. Mautz, “Theory of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 622–628 (1971).
[Crossref]

R. F. Harrington and J. R. Mautz, “Computation of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 629–639 (1971).
[Crossref]

1965 (1)

R. J. Garbacz, “Modal expansions for resonance scattering phenomena,” Proc. IEEE 53(8), 856–864 (1965).
[Crossref]

Bie, S.

Cao, J.

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Cao, Z.

Chakrabarty, A.

S. Ghosal, A. De, R. M. Shubair, and A. Chakrabarty, “Vertical dipole above the lossy dielectric half-space—A characteristic mode analysis,” IEEE Trans. Electromagn. Compat. 62(6), 2832–2841 (2020).
[Crossref]

Chakravarty, S.

S. Chakravarty, R. Mittra, and N. R. Williams, “On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media,” IEEE Trans. Microwave Theory Tech. 49(6), 1050–1059 (2001).
[Crossref]

Chang, H.

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Chang, Y.

Y. Chang and R. F. Harrington, “A surface formulation for characteristic modes of material bodies,” IEEE Trans. Antennas Propag. 25(6), 789–795 (1977).
[Crossref]

R. F. Harrington, J. R. Mautz, and Y. Chang, “Characteristic modes for dielectric and magnetic bodies,” IEEE Trans. Antennas Propag. 20(2), 194–198 (1972).
[Crossref]

Chen, C. H.

Chen, H.

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Chen, K.

Chen, L.

Chen, P. Y.

Chen, Y.

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Y. Chen and C. Wang, Characteristics Modes Theory and Applications in Antenna Engineering (Wiley Publishing, 2015), Chap. 2.

Chen, Z.

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Chen, Z. N.

F. H. Lin and Z. N. Chen, “Resonant metasurface antennas with resonant apertures: Characteristic mode analysis and dual-polarized broadband low-profile design,” IEEE Trans. Antennas Propag. 69(6), 3512–3516 (2021).
[Crossref]

F. H. Lin and Z. N. Chen, “Truncated impedance sheet model for low-profile broadband nonresonant-cell metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(10), 5043–5051 (2018).
[Crossref]

F. H. Lin and Z. N. Chen, “A method of suppressing higher order modes for improving radiation performance of metasurface multiport antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(4), 1894–1902 (2018).
[Crossref]

F. H. Lin and Z. N. Chen, “Low-profile wideband metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 65(4), 1706–1713 (2017).
[Crossref]

Cheng, Q.

J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
[Crossref]

C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
[Crossref]

Cui, L.

Cui, T. J.

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
[Crossref]

C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
[Crossref]

Dai, B.

De, A.

S. Ghosal, A. De, R. M. Shubair, and A. Chakrabarty, “Vertical dipole above the lossy dielectric half-space—A characteristic mode analysis,” IEEE Trans. Electromagn. Compat. 62(6), 2832–2841 (2020).
[Crossref]

Deguchi, H.

M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004).
[Crossref]

Deng, F.

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

Deng, R.

R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
[Crossref]

Ding, G.

Dong, H.

Dong, J.

Du, Y.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Duan, W.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Fan, Q.

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Feng, M.

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

Feng, Y.

Garbacz, R. J.

R. J. Garbacz, “Modal expansions for resonance scattering phenomena,” Proc. IEEE 53(8), 856–864 (1965).
[Crossref]

Ghosal, S.

S. Ghosal, A. De, R. M. Shubair, and A. Chakrabarty, “Vertical dipole above the lossy dielectric half-space—A characteristic mode analysis,” IEEE Trans. Electromagn. Compat. 62(6), 2832–2841 (2020).
[Crossref]

Ghosh, S.

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

Guan, J.

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Guo, Q.

Q. Guo, J. Su, and Z. Li, “Design of circuit analog absorber using characteristic mode analysis,” in IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) (2020), pp. 1–3.

Han, X.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Harrington, R. F.

Y. Chang and R. F. Harrington, “A surface formulation for characteristic modes of material bodies,” IEEE Trans. Antennas Propag. 25(6), 789–795 (1977).
[Crossref]

R. F. Harrington, J. R. Mautz, and Y. Chang, “Characteristic modes for dielectric and magnetic bodies,” IEEE Trans. Antennas Propag. 20(2), 194–198 (1972).
[Crossref]

R. F. Harrington and J. R. Mautz, “Computation of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 629–639 (1971).
[Crossref]

R. F. Harrington and J. R. Mautz, “Theory of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 622–628 (1971).
[Crossref]

He, F.

He, Y.

Hou, J.

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

Hu, D.

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Huang, Y.

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Huang, Z.

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Ishikawa, K.

Y. Okano, S. Ogino, and K. Ishikawa, “Development of optically transparent ultrathin microwave absorber for ultrahigh-frequency RF identification system,” IEEE Trans. Microwave Theory Tech. 60(8), 2456–2464 (2012).
[Crossref]

Järvenpää, S.

P. Yla-Oijala, H. Wallén, and S. Järvenpää, “Theory of characteristic modes for lossy structures: Formulation and interpretation of eigenvalues,” Int. J. Numer. Model. 33(2), e2627 (2020).
[Crossref]

Jiang, J.

Jiang, T.

Jin, L.

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

Knott, E. F.

E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section (SciTech Publishing, 2004), Chap. 8.

Landy, N. I.

N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
[Crossref]

Lehtovuori, A.

P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019).
[Crossref]

Li, L.

L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018).
[Crossref]

Li, M.

R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
[Crossref]

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

Li, R.

Li, T.

Li, W.

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Li, X.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Li, Z.

Q. Guo, J. Su, and Z. Li, “Design of circuit analog absorber using characteristic mode analysis,” in IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) (2020), pp. 1–3.

Lin, F. H.

F. H. Lin and Z. N. Chen, “Resonant metasurface antennas with resonant apertures: Characteristic mode analysis and dual-polarized broadband low-profile design,” IEEE Trans. Antennas Propag. 69(6), 3512–3516 (2021).
[Crossref]

F. H. Lin and Z. N. Chen, “A method of suppressing higher order modes for improving radiation performance of metasurface multiport antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(4), 1894–1902 (2018).
[Crossref]

F. H. Lin and Z. N. Chen, “Truncated impedance sheet model for low-profile broadband nonresonant-cell metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(10), 5043–5051 (2018).
[Crossref]

F. H. Lin and Z. N. Chen, “Low-profile wideband metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 65(4), 1706–1713 (2017).
[Crossref]

Lin, H.

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

Liu, C.

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

Liu, H.

L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018).
[Crossref]

Liu, S.

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

Lv, Z.

L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018).
[Crossref]

Ma, H.

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

Manara, G.

G. Manara, A. Monorchio, and R. Mittra, “Frequency selective surface design based on genetic algorithm,” Electron. Lett. 35(17), 1400–1401 (1999).
[Crossref]

Mautz, J. R.

R. F. Harrington, J. R. Mautz, and Y. Chang, “Characteristic modes for dielectric and magnetic bodies,” IEEE Trans. Antennas Propag. 20(2), 194–198 (1972).
[Crossref]

R. F. Harrington and J. R. Mautz, “Computation of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 629–639 (1971).
[Crossref]

R. F. Harrington and J. R. Mautz, “Theory of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 622–628 (1971).
[Crossref]

Miao, L.

Min, P. P.

Mittra, R.

S. Chakravarty, R. Mittra, and N. R. Williams, “On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media,” IEEE Trans. Microwave Theory Tech. 49(6), 1050–1059 (2001).
[Crossref]

G. Manara, A. Monorchio, and R. Mittra, “Frequency selective surface design based on genetic algorithm,” Electron. Lett. 35(17), 1400–1401 (1999).
[Crossref]

Mock, J. J.

N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
[Crossref]

Monorchio, A.

G. Manara, A. Monorchio, and R. Mittra, “Frequency selective surface design based on genetic algorithm,” Electron. Lett. 35(17), 1400–1401 (1999).
[Crossref]

Mou, N.

Ni, W. X.

Ogino, S.

Y. Okano, S. Ogino, and K. Ishikawa, “Development of optically transparent ultrathin microwave absorber for ultrahigh-frequency RF identification system,” IEEE Trans. Microwave Theory Tech. 60(8), 2456–2464 (2012).
[Crossref]

Ohira, M.

M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004).
[Crossref]

Okano, Y.

Y. Okano, S. Ogino, and K. Ishikawa, “Development of optically transparent ultrathin microwave absorber for ultrahigh-frequency RF identification system,” IEEE Trans. Microwave Theory Tech. 60(8), 2456–2464 (2012).
[Crossref]

Padilla, W. J.

N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
[Crossref]

Pang, Y.

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

Qiang, R.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Qiu, C. W.

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

Qu, S.

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

Ramakrishna, S. A.

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

Ramkumar, J.

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

Rozanov, K. N.

K. N. Rozanov, “Ultimate thickness to bandwidth ratio of radar absorbers,” IEEE Trans. Antennas Propag. 48(8), 1230–1234 (2000).
[Crossref]

Saikia, M.

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

Sajuyigbe, S.

N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
[Crossref]

Shaeffer, J. F.

E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section (SciTech Publishing, 2004), Chap. 8.

Sheokand, H.

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

Shi, T.

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

Shigesawa, H.

M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004).
[Crossref]

Shubair, R. M.

S. Ghosal, A. De, R. M. Shubair, and A. Chakrabarty, “Vertical dipole above the lossy dielectric half-space—A characteristic mode analysis,” IEEE Trans. Electromagn. Compat. 62(6), 2832–2841 (2020).
[Crossref]

Sihvola, A.

P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018).
[Crossref]

Singh, G.

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

Smith, D. R.

N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
[Crossref]

Song, L.

R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
[Crossref]

Song, Z. C.

Srivastava, K. V.

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

Su, J.

Q. Guo, J. Su, and Z. Li, “Design of circuit analog absorber using characteristic mode analysis,” in IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) (2020), pp. 1–3.

Sui, S.

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

Tang, M. C.

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

Tang, R.

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

Tian, C.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Tsai, J. H.

Tsuji, M.

M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004).
[Crossref]

Tuley, M. T.

E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section (SciTech Publishing, 2004), Chap. 8.

Tzarouchis, D. C.

P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018).
[Crossref]

Viikari, V.

P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019).
[Crossref]

Wallen, H.

P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019).
[Crossref]

P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018).
[Crossref]

Wallén, H.

P. Yla-Oijala, H. Wallén, and S. Järvenpää, “Theory of characteristic modes for lossy structures: Formulation and interpretation of eigenvalues,” Int. J. Numer. Model. 33(2), e2627 (2020).
[Crossref]

Wan, X.

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

Wang, C.

Y. Chen and C. Wang, Characteristics Modes Theory and Applications in Antenna Engineering (Wiley Publishing, 2015), Chap. 2.

Wang, H.

Wang, J.

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

Wang, N.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Wang, Y.

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Williams, N. R.

S. Chakravarty, R. Mittra, and N. R. Williams, “On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media,” IEEE Trans. Microwave Theory Tech. 49(6), 1050–1059 (2001).
[Crossref]

Wu, T.

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Wu, Y.

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

Xi, R.

L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018).
[Crossref]

Xiao, P.

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Xiong, J.

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

Xu, Z.

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

Yang, J.

J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
[Crossref]

C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
[Crossref]

Yang, L.

Yi, D.

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

Yla-Oijala, P.

P. Yla-Oijala, H. Wallén, and S. Järvenpää, “Theory of characteristic modes for lossy structures: Formulation and interpretation of eigenvalues,” Int. J. Numer. Model. 33(2), e2627 (2020).
[Crossref]

P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019).
[Crossref]

P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018).
[Crossref]

Zha, D.

Zhang, C.

J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
[Crossref]

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
[Crossref]

Zhang, K.

R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
[Crossref]

Zhang, L.

Y. Zhang, H. Dong, N. Mou, L. Chen, R. Li, and L. Zhang, “High-performance broadband electromagnetic interference shielding optical window based on a metamaterial absorber,” Opt. Express 28(18), 26836–26849 (2020).
[Crossref]

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

Zhang, Q.

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

Zhang, T.

R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
[Crossref]

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Zhang, Y.

Y. Zhang, H. Dong, N. Mou, L. Chen, R. Li, and L. Zhang, “High-performance broadband electromagnetic interference shielding optical window based on a metamaterial absorber,” Opt. Express 28(18), 26836–26849 (2020).
[Crossref]

D. Zha, J. Dong, Z. Cao, Y. Zhang, F. He, R. Li, Y. He, L. Miao, S. Bie, and J. Jiang, “A multimode, broadband and all-inkjet-printed absorber using characteristic mode analysis,” Opt. Express 28(6), 8609–8618 (2020).
[Crossref]

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Zhao, J.

Y. Zheng, K. Chen, T. Jiang, J. Zhao, and Y. Feng, “Multi-octave microwave absorption via conformal metamaterial absorber with optical transparency,” J. Phys. D: Appl. Phys. 52(33), 335101 (2019).
[Crossref]

J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
[Crossref]

T. Li, K. Chen, G. Ding, J. Zhao, T. Jiang, and Y. Feng, “Optically transparent metasurface Salisbury screen with wideband microwave absorption,” Opt. Express 26(26), 34384–34395 (2018).
[Crossref]

C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
[Crossref]

K. Chen, L. Cui, Y. Feng, J. Zhao, T. Jiang, and B. Zhu, “Coding metasurface for broadband microwave scattering reduction with optical transparency,” Opt. Express 25(5), 5571–5579 (2017).
[Crossref]

Zheng, Y.

Y. Zheng, K. Chen, T. Jiang, J. Zhao, and Y. Feng, “Multi-octave microwave absorption via conformal metamaterial absorber with optical transparency,” J. Phys. D: Appl. Phys. 52(33), 335101 (2019).
[Crossref]

Zhou, R.

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

Zhu, B.

Zhu, J. Q.

Adv. Mater. (1)

Y. Zhang, Y. Huang, T. Zhang, H. Chang, P. Xiao, H. Chen, Z. Huang, and Y. Chen, “Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam,” Adv. Mater. 27(12), 2049–2053 (2015).
[Crossref]

Adv. Opt. Mater. (1)

D. Hu, J. Cao, W. Li, C. Zhang, T. Wu, Q. Fan, Z. Chen, Y. Wang, and J. Guan, “Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators,” Adv. Opt. Mater. 5(13), 1700109 (2017).
[Crossref]

Adv. Theory Simul. (1)

Q. Zhang, C. Liu, X. Wan, L. Zhang, S. Liu, Y. Zhang, and T. J. Cui, “Machine-learning designs of anisotropic digital coding metasurfaces,” Adv. Theory Simul. 2(2), 1800132 (2019).
[Crossref]

Appl. Phys. Express (1)

L. Li, R. Xi, H. Liu, and Z. Lv, “Broadband polarization-independent and low-profile optically transparent metamaterial absorber,” Appl. Phys. Express 11(5), 052001 (2018).
[Crossref]

Appl. Phys. Lett. (2)

J. Zhao, C. Zhang, Q. Cheng, J. Yang, and T. J. Cui, “An optically transparent metasurface for broadband microwave antireflection,” Appl. Phys. Lett. 112(7), 073504 (2018).
[Crossref]

C. Zhang, Q. Cheng, J. Yang, J. Zhao, and T. J. Cui, “Broadband metamaterial for optical transparency and microwave absorption,” Appl. Phys. Lett. 110(14), 143511 (2017).
[Crossref]

Appl. Surf. Sci. (1)

W. Duan, X. Li, Y. Wang, R. Qiang, C. Tian, N. Wang, X. Han, and Y. Du, “Surface functionalization of carbonyl iron with aluminum phosphate coating toward enhanced anti-oxidative ability and microwave absorption properties,” Appl. Surf. Sci. 427(part A), 594–602 (2018).
[Crossref]

Electron. Lett. (1)

G. Manara, A. Monorchio, and R. Mittra, “Frequency selective surface design based on genetic algorithm,” Electron. Lett. 35(17), 1400–1401 (1999).
[Crossref]

IEEE Antennas Wirel. Propagat. Lett. (1)

H. Sheokand, G. Singh, S. Ghosh, J. Ramkumar, S. A. Ramakrishna, and K. V. Srivastava, “An optically transparent broadband microwave absorber using interdigital capacitance,” IEEE Antennas Wirel. Propagat. Lett. 18(1), 113–117 (2019).
[Crossref]

IEEE Trans. Antennas Propag. (12)

R. F. Harrington and J. R. Mautz, “Theory of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 622–628 (1971).
[Crossref]

F. H. Lin and Z. N. Chen, “Low-profile wideband metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 65(4), 1706–1713 (2017).
[Crossref]

F. H. Lin and Z. N. Chen, “Truncated impedance sheet model for low-profile broadband nonresonant-cell metasurface antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(10), 5043–5051 (2018).
[Crossref]

F. H. Lin and Z. N. Chen, “A method of suppressing higher order modes for improving radiation performance of metasurface multiport antennas using characteristic mode analysis,” IEEE Trans. Antennas Propag. 66(4), 1894–1902 (2018).
[Crossref]

F. H. Lin and Z. N. Chen, “Resonant metasurface antennas with resonant apertures: Characteristic mode analysis and dual-polarized broadband low-profile design,” IEEE Trans. Antennas Propag. 69(6), 3512–3516 (2021).
[Crossref]

P. Yla-Oijala, A. Lehtovuori, H. Wallen, and V. Viikari, “Coupling of characteristic modes on PEC and lossy dielectric structures,” IEEE Trans. Antennas Propag. 67(4), 2565–2573 (2019).
[Crossref]

P. Yla-Oijala, H. Wallen, D. C. Tzarouchis, and A. Sihvola, “Surface integral equation-based characteristic mode formulation for penetrable bodies,” IEEE Trans. Antennas Propag. 66(7), 3532–3539 (2018).
[Crossref]

M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, “Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique,” IEEE Trans. Antennas Propag. 52(11), 2925–2931 (2004).
[Crossref]

R. F. Harrington and J. R. Mautz, “Computation of characteristic modes for conducting bodies,” IEEE Trans. Antennas Propag. 19(5), 629–639 (1971).
[Crossref]

R. F. Harrington, J. R. Mautz, and Y. Chang, “Characteristic modes for dielectric and magnetic bodies,” IEEE Trans. Antennas Propag. 20(2), 194–198 (1972).
[Crossref]

Y. Chang and R. F. Harrington, “A surface formulation for characteristic modes of material bodies,” IEEE Trans. Antennas Propag. 25(6), 789–795 (1977).
[Crossref]

K. N. Rozanov, “Ultimate thickness to bandwidth ratio of radar absorbers,” IEEE Trans. Antennas Propag. 48(8), 1230–1234 (2000).
[Crossref]

IEEE Trans. Electromagn. Compat. (1)

S. Ghosal, A. De, R. M. Shubair, and A. Chakrabarty, “Vertical dipole above the lossy dielectric half-space—A characteristic mode analysis,” IEEE Trans. Electromagn. Compat. 62(6), 2832–2841 (2020).
[Crossref]

IEEE Trans. Microwave Theory Tech. (2)

S. Chakravarty, R. Mittra, and N. R. Williams, “On the application of the microgenetic algorithm to the design of broad-band microwave absorbers comprising frequency-selective surfaces embedded in multilayered dielectric media,” IEEE Trans. Microwave Theory Tech. 49(6), 1050–1059 (2001).
[Crossref]

Y. Okano, S. Ogino, and K. Ishikawa, “Development of optically transparent ultrathin microwave absorber for ultrahigh-frequency RF identification system,” IEEE Trans. Microwave Theory Tech. 60(8), 2456–2464 (2012).
[Crossref]

Int. J. Numer. Model. (1)

P. Yla-Oijala, H. Wallén, and S. Järvenpää, “Theory of characteristic modes for lossy structures: Formulation and interpretation of eigenvalues,” Int. J. Numer. Model. 33(2), e2627 (2020).
[Crossref]

J. Appl. Phys. (2)

Y. Wu, H. Lin, J. Xiong, J. Hou, R. Zhou, F. Deng, and R. Tang, “A broadband metamaterial absorber design using characteristic modes analysis,” J. Appl. Phys. 129(13), 134902 (2021).
[Crossref]

H. Sheokand, S. Ghosh, G. Singh, M. Saikia, K. V. Srivastava, J. Ramkumar, and S. A. Ramakrishna, “Transparent broadband metamaterial absorber based on resistive films,” J. Appl. Phys. 122(10), 105105 (2017).
[Crossref]

J. Phys. D: Appl. Phys. (2)

Y. Zheng, K. Chen, T. Jiang, J. Zhao, and Y. Feng, “Multi-octave microwave absorption via conformal metamaterial absorber with optical transparency,” J. Phys. D: Appl. Phys. 52(33), 335101 (2019).
[Crossref]

S. Sui, H. Ma, J. Wang, Y. Pang, M. Feng, Z. Xu, and S. Qu, “Absorptive coding metasurface for further radar cross section reduction,” J. Phys. D: Appl. Phys. 51(6), 065603 (2018).
[Crossref]

Mater. Des. (1)

R. Deng, K. Zhang, M. Li, L. Song, and T. Zhang, “Targeted design, analysis and experimental characterization of flexible microwave absorber for window application,” Mater. Des. 162, 119–129 (2019).
[Crossref]

Opt. Express (6)

Phys. Rev. Lett. (1)

N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, “Perfect metamaterial absorber,” Phys. Rev. Lett. 100(20), 207402 (2008).
[Crossref]

Proc. IEEE (1)

R. J. Garbacz, “Modal expansions for resonance scattering phenomena,” Proc. IEEE 53(8), 856–864 (1965).
[Crossref]

Other (5)

Y. Chen and C. Wang, Characteristics Modes Theory and Applications in Antenna Engineering (Wiley Publishing, 2015), Chap. 2.

T. Shi, M. C. Tang, D. Yi, L. Jin, M. Li, J. Wang, and C. W. Qiu, “Near-omnidirectional broadband metamaterial absorber for TM-polarized wave based on radiation pattern synthesis,” IEEE Trans. Antennas Propagat. (to be published).

E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section (SciTech Publishing, 2004), Chap. 8.

CST Computer Simulation Technology. (2020) CST MWS. http://www.cst.com .

Q. Guo, J. Su, and Z. Li, “Design of circuit analog absorber using characteristic mode analysis,” in IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) (2020), pp. 1–3.

Data availability

Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.

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Figures (12)

Fig. 1.
Fig. 1. Energy conversion by the (a) lossless structure (ideal case of scattering), (b) lossy structure (ideal case of absorption) and (c) lossy structure (actual case of coexistence of scattering and absorption).
Fig. 2.
Fig. 2. Schematics of the patch-type metabsorber array and its unit cell configuration.
Fig. 3.
Fig. 3. E-field distribution produced by a 6 GHz wave at x = 0 mm for: (a) lossy sheet with periodic boundary; (b) lossless sheet with periodic boundary and (c) lossless sheet with absorbing boundary. E-field distribution produced by a 6 GHz wave at z = 6.5 mm for: (d) lossy sheet with periodic boundary; (e) lossless sheet with periodic boundary and (f) lossless sheet with absorbing boundary.
Fig. 4.
Fig. 4. Comparisons of E-field amplitudes produced by a 6 GHz wave at z = 6.5 mm and x = 6 mm: (a) between lossy sheet and lossless sheet and (b) between periodic and absorbing boundaries.
Fig. 5.
Fig. 5. Comparison between the absorption power and scattering power (Σ|MWC|2) of the patch-type metabsorber.
Fig. 6.
Fig. 6. Normalized |MWC|2 for the patch-type metabsorber at (a) 9 GHz, (b) 23.5 GHz and (c) 34 GHz.
Fig. 7.
Fig. 7. Modal radiation patterns of the patch-type metabsorber: (a–c) modes 12, 15, and 8 at 9 GHz, respectively; (d–f) modes 29, 3, and 8 at 23.5 GHz, respectively; (h–j) modes 30, 14, and 10 at 34 GHz, respectively.
Fig. 8.
Fig. 8. Geometrical modelling of the three metabsorbers and the patch and ground layers: (a) patch-type metabsorber (MA-A); (b) ring-type metabsorber (MA-B); (c) full metabsorber (MA-C); (d) patch layer; (e) ring layer and (f) ground layer.
Fig. 9.
Fig. 9. Absorption of the full metabsorber (MA-C). Σ|MWC|2 values of the patch-type (MA-A) and ring-type (MA-B) metabsorbers.
Fig. 10.
Fig. 10. The normalized |MWC|2 for (a) MA-B (ring-type metabsorber) and (d) MA-C (full metabsorber) at 23.5 GHz, and the modal radiation patterns for (b) MA-B and (e) MA-C generated by the modal current J5 and J7 on the ring layer of (c) MA-B and (f) MA-C, respectively.
Fig. 11.
Fig. 11. Simulated absorptivity as a function of incidence angle, for (a) TE and (b) TM polarizations.
Fig. 12.
Fig. 12. Schematics of the experimental setup for measuring the reflectance of MA-C and comparison between the measured and simulated absorptions of MA-C. Inset shows photograph of the fabricated metabsorber sample.

Tables (2)

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Table 1. Summary of E-field distribution comparisons for approximations

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Table 2. Comparison with other transparent wideband metabsorbers

Equations (2)

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| 0 ln | ρ ( λ ) | d λ | 2 π 2 μ s d
Γ 0 ( λ max  -  λ min ) 40 π 2 d / ln10 172 d