Estimation of reflection loss of lossy dielectric powders using coaxial line based guided wave technique for conventional cement based microwave absorber applications.

• Scattering matrix measurements on coaxial transmission line, filled with test material. • Algorithm to estimate reflection loss for test material from scattering matrix measurements. • Test material: Ash by-products from Steel Plants – presently dumped in land fills, research on utilizing these ashes as conductive filler for microwave absorber applications. • Targeted Domain: Cement based Microwave Absorber for Low-cost large area absorber deployment. Cement based EM smart structures. • Large area absorber: Required for EMI shielding at structural level for critical infrastructure including data servers from intentional EMI and non-intentional EMI. Coaxial transmission line technique to determine Plane Wave Reflection Loss of dielectric powders is proposed. The technique provides rapid determination of suitability of powders as conductive filler for Microwave Absorbers, specifically cement based Absorber. Ash by-product from steel industry including Argon Oxygen Decarburization (AOD), Acid Recovery Station (ARS) and Electric Arc Furnace (EAF) are considered over frequency range 1–12 GHz. Scattering parameters (S-matrix) of ash filled coaxial lines are measured. Short-Open technique is adopted. Formulation to compute reflection loss from measured S 11 is presented. Teflon, with known reflection loss, is considered for validation. A 10 % error in computed results is observed in range 1–4 GHz, and 10–15 % in range 4–12 GHz. Broadband MAM characterization employing Free Space Methods involve enormous material requirement, frequency dependent prototype dimensions and anechoic chambers. The error percentage notwithstanding, the technique provides rapid estimates, enabling smart selection of conductive fillers, providing cost and time reduction. [ABSTRACT FROM AUTHOR]