Experimental Study of Electromagnetic Wave Absorbers to Design an Anechoic Chamber

Abstract

To study Electromagnetic (EM) wave absorbency characteristics of carbon loaded dielectrics, multiple test samples of wood and wood charcoal are prepared. Direct measurement of EM wave absorbency of test samples is not possible with available testing and measurement equipment. Therefore EM wave absorbency is calculated using Reflection Coefficient and Transmitted Power through the test sample. Reflection Coefficient and Transmitted Power through the test samples is measured using transmission line technique. Load Impedance, Permittivity, Loss Tangent, Reflection Coefficient and Return Loss of test samples, in free space, is calculated. Performanceofabsorbers,havingsameelectromagneticparametersastest samples and pyramidal shape, is predicted. A new technique for EM wave absorber synthesis is proposed. Modification in Anechoic Chamber (A.C.) geometry is also proposed to allow near normal incidenceoverthewholeabsorbingstructurelinedinsidethechamber.