An ultrabroadband metamaterial absorber structure based on a periodic array of metallic-dielectric multilayered conical frustums is numerically investigated and proposed. The metamaterial absorber indicated an absorptivity of higher than 90%, which covered the visible and near-infrared region at 480-1480 nm, and a relative absorption bandwidth of 102%. The high absorptivity can be maintained with large incident angles up to 60°under both transverse electric and transverse magnetic polarizations. Furthermore, the proposed absorber exhibits polarization insensitivity owing to its rotational symmetry structure. Compared with the previously reported ultrabroadband metamaterial absorbers, the design in this work indicates high practical feasibility in terms of a compact structure for a large bandwidth, a wide incident angle, and polarization insensitivity, thereby suggesting its promising application, for example, in solar cells and thermal emitters.

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We present a broadband metamaterial absorber (MA) in the microwave frequency regime by utilizing a periodic array of metallic‐dielectric multilayered conical frustums. The absorption performance of the proposed MA is simulated and analyzed in details by using the finite‐difference time domain method. The absorption efficiencies greater than 90% can be achieved while maintaining with large incidence angles up to 600. Furthermore, the perfect polarization independence is also obtained due to its rotational symmetrical structure. The obtained excellent absorber performance reveals that the proposed MA is promising candidates for camouflage and stealth radome applications. Moreover, we believe that this structure can be extended to design perfect broadband absorbers in the terahertz, infrared, and optical frequencies. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1157–1161, 2017

A microstrip antenna using negative permittivity metamaterial based on complementary split ring resonator (CSRR)-loaded ground has been investigated in order to miniaturize the size and improve the antenna characteristics. The antennas are designed on FR4 material and simulated results are provided by HFSS software. The metamaterial antenna is reduced 77 % the antenna size compared to the normal microstrip antenna. Furthermore, compared with the normal microstrip antenna, the antenna characteristics of the metamaterial antenna are improved significantly. The proposed metamaterial antenna achieves the antenna resonate at 2.45 GHz, the gain of higher than 6.5 dB and the bandwidth of 110 MHz through the whole WLAN band. The obtained results indicate that the proposed antenna is a good candidate for WLAN applications.