Akademik Veri Yönetim Sistemi
Materials Science and Engineering B: Solid-State Materials for Advanced Technology, cilt.294, 2023 (SCI-Expanded)
The effects of surface electrical conductivity and cascading order of ITO surface modified glass fiber woven fabrics (GFWF) on the electromagnetic (EM) behavior of hybrid type multilayered absorber structure were investigated. Additional objective was to create a design guideline for a multilayered absorbing structure according to the needs of specific EM wave absorber applications. For this purpose, indium tin oxide (ITO) sols were deposited on GFWFs by spray pyrolysis technique. The electrical conductivity of these conducting layers was controlled to incorporate EM wave absorbing characteristics to glass fabrics. Surface modified fabrics were then used as reinforcement in a hybrid type multilayered EM wave absorbing structure which is a combination of Jaumann and graded type absorbers effective in 8–12 GHz frequency range (X-band). The highest absorption performance design has been formed by cascading six ITO coated fabrics with gradually increasing electrical conductivity gradient from the front to back layer of the structure. The electromagnetic behavior of the multilayered absorber was tested both with and without metallic backing. The absorber design showed ∼−11 dB reflection loss and ∼−9 dB transmission loss corresponding to ∼80 % average absorption without metallic backing, while its reflection loss and average absorption values were ∼−10.5 dB and ∼93 %, respectively, with metallic backing. The front layer of the multilayered structure with the lowest surface electrical conductivity provided impedance matching between air and receiving surface of the structure minimizing reflection, where the gradual increase in surface conductivity of the layers towards the back provided balanced internal reflection and transmission leading to high overall EM wave absorption. Consequently, by controlling the grading of the surface conductivity of the layers through the thickness, responses of the absorbers can be adjusted to provide tailored characteristics for the required EM wave absorption levels.