A metamaterial absorber (MA) based sensor is designed and analysed for various important applications including pressure, temperature, density, and humidity sensing. Material parameters, as well as equivalent circuit model have been extracted and explained. After obtaining a perfect absorption (PA) at around 6.46 GHz and 7.68 GHz, surface current distributions at resonance points have been explained. Since bandwidth and applicability to different sensor applications are important for metamaterial sensor applications, we have realized distinctive sensor demonstrations for pressure, temperature, moisture content and density and the obtained results have been compared with the current literature. The proposed structure uses the changes on the overall system resonance frequency which is caused by the sensor layer's dielectric constant that varies depending on the electromagnetic behaviour of the sample placed in. This model can be adapted to be used in sensor applications including industrial, medical and agricultural products.

Abstract-In this work, frequency behavior of the multilayer structure comprised of double-negative (DNG) and dielectric slabs is presented in detail. The multilayer structure consists of N pieces DNG and dielectric slabs with different material properties and thicknesses. The incident electric field is assumed to be a monochromatic plane wave with any arbitrary polarization. The DNG layers are realized using the parameters of Lorentz/Drude type metamaterials. Transfer matrix method is used in the analysis to find the characteristics of the reflected and transmitted powers. Finally, the computations of the powers for two structures are demonstrated in numerical results for the application to design efficient filters at the microwave, millimeter wave, and optical frequency regions.

Abstract-We design, characterize, and analyze a new kind of metamaterial (MTM) absorber (MA) in different frequency regions for the solar cell applications. This MTM based structure is particularly presented in a range of the solar spectrum in order to utilize the solar energy effectively. The proposed MTM based solar cell provides perfect absorption for both infrared and visible frequency ranges and can be used for the realization of more efficient new solar cells. The structure is also tested in terms of the polarization angle independency. The suggested MA has a simple configuration which introduces flexibility to adjust its MTM properties to be used in solar cells and can easily be re-scaled for other frequency ranges. Our experimental results in microwave frequencies confirm the perfect absorption for the resonance frequency and agree with the simulation results. This means that the developed MA for solar cells will offer perfect absorption in infrared and even in visible frequencies.

Abstract-Dual-band metamaterial absorber (MA) with polarization independency based on omega (Ω) resonator with gap and octastar strip (OSS) configuration is presented both numerically and experimentally. The suggested MA has a simple configuration which introduces flexibility to adjust its metamaterial (MTM) properties and easily re-scale the structure for other frequencies. In addition, the dualband character of the absorber provides additional degree of freedom to control the absorption band(s). Two maxima in the absorption are experimentally obtained around 99% at 4.0 GHz for the first band and 79% at 5.6 GHz for the second band which are in good agreement with the numerical simulations (99% and 84%, respectively). Besides, numerical simulations validate that the MA could achieve very high absorption at wide angles of incidence for both transverse electric (T E) and transverse magnetic (T M ) waves. The proposed MA and its variations enable myriad potential applications in medical technologies, sensors, modulators, wireless communication, and so on.

Abstract-In this paper, we study tunable metamaterial structures whose unit cell has triangular split ring resonator and wire strip for S-and C-microwave bands. Three types of new metamaterials, concentric and non-concentric configurations, are designed, and their electromagnetic response is investigated. Constitutive and S parameters are computed using retrieval algorithm to demonstrate the properties of the proposed new metamaterial designs. In addition, the electric field distribution on the metallic parts of the structure is illustrated for one design of the each sample. It is shown that the studied new metamaterials exhibit double negative properties in the frequency region of interest. The main advantage of this study based on the proposed structures is having the tunability in terms of the substrate thickness and the possibility of pronounced loss reduction.