Synthesis and characterization of flexible CaCoAlFe2O4 based microwave substrate for triband polarization-insensitive metamaterial absorber

Abstract

This study investigated CaxCo(0.90-x)Al.01Fe2O4 nanoparticle synthesized using the sol–gel synthesis method to achieve a flexible substrate with a high dielectric constant value. The XRD, FESEM, and dielectric characteristic is analyzed to explore the performance of the suggested Ox Wheels-shaped (OWS) metamaterial absorber unit cell. The X-ray diffraction (XRD) analysis found significant peaks at 30° (318), 33° (176), 35° (794), 43° (232), 53° (116), 57° (256), 62° (304), and 74° (126) planes. The dielectric constant values of the prepared nanomaterial materials are 4.52 (X = 90 %), 4.73 (X = 60 %), and 5.07 (X = 30 %) due to the deviations in raw material compositions. The prepared, flexible substrate is used in the anticipated OWS metamaterial absorber unit cell, and analysis has been widely considered and continuously concerned due to their excellent ultra-thin thickness, lightweight, and high absorbance resonance features. The predicted structure reached S21 response at 3.47 GHz, 7.05 GHz, and 10.76 GHz with the magnitude of −24.11 dB, −17.07 dB, and −19.19 dB, respectively, using CST simulation software. The absorber prototype is measured for further investigation within the frequency range of 2.25–2.76, 5.84–6.15 GHz, and 9.63–9.76 GHz, where maximum magnitude is achieved at 2.50 GHz, 6.02 GHz, and 9.70 GHz, respectively. This specific resonance frequency reached the highest 99.61 %, 98.03 %, and 98.79 % absorption, which covers the S, C, and X band frequency spectrum. Various electrical, magnetic, mechanical, and multi-parameter responses are examined to achieve almost perfect absorption (PA). The enormous range of possible uses of metamaterial, such as absorber wave modification, infrared imaging, radiative cooling, energy harvesting, and chemical detection, makes it appreciated. The CaCoAlFe2O4 ferrite-based flexible metamaterial absorber structure has ultra-thin, flexible, and non-corrosive advantages.