Transmission through a wall (3/5) Therefore: a-av Er=E0e“ S(r)=S(0).e-2r Transmission through a wall (3/5) jk = α + jβ ≈ ω c ε r ′ ε r ′′ 2ε r ′ + j ⎛ ⎝ ⎜ ⎜ ⎞ ⎠ ⎟ ⎟ ⇒ α ≈ ω c ε r ′ ε r ′′ 2ε r ′ ⎛ ⎝ ⎜ ⎜ ⎞ ⎠ ⎟ ⎟ β ≈ ω c ε r ′ ⎧ ⎨ ⎪ ⎪ ⎩ ⎪ ⎪ Therefore: E(r) = E(0) ⋅ e−αr S(r) = S(0)⋅ e−2αr