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In this study, a resistor-loaded wideband conformal metamaterial absorber has been designed, fabricate, and analyzed experimentally. The proposed absorber consists of lumped resistors loaded on cross-shaped resonators at the top side of the flexible substrate and copper metal film separated by flexible foam on the substrate's backside. The total thickness of the absorber is 0.07λ o , where λ o is the lowest absorption frequency. The simulated results exhibited absorption from 3.25 − 13.6 GHz (absorption bandwidth 123%). The wideband absorption mechanism of the absorber was analyzed through the equivalent circuit model and parametric study. The designed structure has been tested on the planar and curved surfaces and measured the results. The simulated and experimental results have good agreement between them. The designed absorber can be suitable for scientific and military applications as of its wideband absorption bandwidth, polarization-insensitive, and conformability. [ABSTRACT FROM AUTHOR]

A triple-band polarization-independent conformal absorber for C- and X-frequency bands have been presented. The designed absorber comprises a Jerusalem cross resonator at the center, surrounded by a quarter part of a square rings resonator with different sizes at each corner on a metal grounded dielectric substrate. The unit cell size is 0.23λ o × 0.23λ o and thickness of λ o /153 at frequency 6.16 GHz. The absorption peaks were obtained at frequencies 6.16 GHz, 9.22 GHz, and 11.6 GHz with absorptivity 95%, 96%, and 97%, respectively. It exhibited full wave at half maximum (FWHM) bandwidths of 160 MHz bands (6.04 GHz–6.20 GHz, 240 MHz (9.09 GHz–9.33 GHz), and 260 MHz (11.57 GHz−11.83 GHz), respectively. The designed absorber is shown four-fold symmetry, which makes it polarization independent. Normalized impedance and surface current distributions for all three absorption frequencies are analyzed for understanding the absorption phenomenon. The designed absorber has been tested for the curved surfaces with different central angles to show its conformal behavior, and it is perceived that measured results and simulated results have good agreement between them. [ABSTRACT FROM AUTHOR]

A compact, ultrathin conformal metamaterial dual‐band absorber for curved surfaces has been presented in this article. The absorber unit cell composed of circular and split ring resonators which are connected with plus‐shaped structure. The proposed absorber unit cell is compact in size (0.22λo × 0.22λo) and as well as ultrathin thickness (0.006λo), where λo is the wavelength at 5.8 GHz. The designed absorber gives two absorption tips at 5.8 and 7.7 GHz with more than 90% absorptivity. The full width at half maximum bandwidths are 220 MHz (5.67‐5.89 GHz) and 250 MHz (7.58‐7.83 GHz). The proposed conformal absorber is sensitive to the polarization angle and has a stable absorptivity over a wide range of incident electromagnetic wave. The parametric analysis and equivalent transmission line model have been investigated. The surface current and electric field distribution also discussed for understanding the absorption mechanism. To analyze the performance of proposed absorber on the curved surfaces, it is wrapped on the different radius of cylindrical surface and measured the absorptivity. Simulated and measured results have good agreement between them. [ABSTRACT FROM AUTHOR]

A small size, planar and co‐planar waveguide fed metamaterial inspired antenna is proposed for ultra‐wideband (UWB) application. The main radiating element consists of three split‐ring resonators (SRR) and placed along one axis. Moreover, coplanar waveguide (CPW)‐fed line along with modified ground plane is used to improve the impedance matching. The physical size of proposed antenna is 25(W) × 22 (L) × 1.6 (H) mm3. The CPW‐fed metamaterial inspired antenna provides bandwidth of 10.4 GHz from 3.1 to 13.5 GHz based on the 3:1 (voltage standing wave ratio [VSWR] <2). Over the range of UWB frequency, peak realized gain varies from 2.5 to 4 dBi. The proposed antenna provides omnidrectional radiation patterns. Further, fidelity factor of the proposed antenna is also calculated and measured. The calculated fidelity factor is suitable for UWB applications. Finally, prototype of the antenna is developed and tested using network analyzer. The simulated and measured results are in good agreement. [ABSTRACT FROM AUTHOR]