Ain Shams Engineering Journal (Dec 2024)
Design and analysis of quad-band metamaterial absorber for permittivity sensing with phase evolved equivalent circuit analysis
Abstract
This article proposes a metamaterial absorber (MMA) based sensor. MMA applications have received significant interest across multiple domains, including their use in sensors, wireless communication, detectors, emitters, antenna design, and spatial light modulators. In the field of microwave absorption, multiband absorbers have received a lot of attention. The absorber suggested in this study consists of four-square split-ring resonators (SRR) with an inner star shape. This configuration is designed to produce four distinct resonances at 4.685 GHz, 6.434 GHz, 8.0869 GHz, and 10.974 GHz. The associated absorption rates for these resonances are 86.97 %, 99.74 %, 99.95 %, and 98.43 %, respectively. The study involved the extraction and subsequent analysis of the complex values related to the permittivity, permeability, refractive index, and impedance of MMA. This research examined the MMA’s absorption mechanism by analyzing it through a magnetic field, an electric field, and surface current distribution. The proposed unit cell is employed as a permittivity sensor due to the strong electric field it produces from SRR. The permittivity values of Rogers RT5880, Roger RT6202, and Roger RO3035 are calculated using the equation. The sample’s thickness range is finalized from 0.2 to 1 mm by examining the e-field density. The average and normalized sensitivity are 380.19 MHz and 6.935 %, higher than the recent permittivity sensor. Additionally, the sensor is equipped with an un-metalized Roger RT5880 dielectric slab with three 1.5 mm (diameter) holes. The holes caused Roger RT5880′s dielectric constant to change; the sensor effectively traced the change in the sample’s dielectric constant. Overall, the proposed material exhibits a high absorption efficiency, miniature size (10 × 10 mm2), low cost, simple structure, and can resist the environmental factors that cause cross-sensitivity, making it an attractive candidate for permittivity sensors for solid substrates.
