Comparison between the analytical and numerical results for the real and imaginary part of the normalized 1D electric field intensity E(ρ = r₀/2, φ = π/2, z) [V/m] and magnetic field intensity H(ρ = r₀/2, φ = π/2, z) [T] in the longitudinal (yz) plane inside the circular waveguide. The subfigures (a) and (b) relate to the real and imaginary part of the normalized 1D electric field intensity E(ρ = r₀/2, φ = π/2, z) [V/m], and the subfigures (c) and (d) relate to the real and imaginary part of the normalized 1D magnetic field intensity H(ρ = r₀/2, φ = π/2, z) [T]. Here the transition parameter is z₀ = 0.05 m, the relative permittivities are ε₁ = 1 − j0.1 and ε₂ = 3 − j0.3, and we assume the permeability of free space.