fig1

Figure 1. Theoretical determination of optimal permittivity for broadband EM wave absorption based on transmission line theory. (A) ε_r', and (B) ε_r'' as a function of frequency with different coating thicknesses (1.50, 1.75, and 2.00 mm); (C) Corresponding RL values calculated using the extracted permittivity. Frequency dependence of the parameter (D) C₁, and (E) C₂; (F) Simulated RL values using the constructed optimal permittivity; (G) Electrical thickness calculated from the constructed permittivity defined by Equations (9) and (10). (H) Electrical thickness, and (I) normalized dielectric loss factor recalculated from the RL-minimized permittivity extracted at each frequency-thickness point. EM: Electromagnetic; RL: reflection loss.