
22 Microwave Engineering
where
γ ωµ σ ωε α β= + = +j j j( )
(2.8b)
As stated earlier the real part of solution to Equation 2.8a, representing
only forward wave, is
Re[ ( , )] cos( )E x t C e t x
y
x
= −
−
1
α
ω β
(2.9)
Plots of E
y
from expressions of Equation 2.9 are shown in Figure 2.3, which
represents a pattern of travelling wave with attenuation.
For lossy medium (
σ
≠ 0) the ratio E/H =
η
= √{j
ωμ
/(
σ
+ j
ωε
)}].
2.6 Conductors and Dielectrics
In view of Equation 2.1a the magnitude of the ratio of conduction current
density and displacement current density (for sinusoidal time variation) can
be written as
J
J
E
E
d
= =
σ
ωε
σ
ωε
(2.10)
This ratio {(
σ
/
ωε
) = 1} is ...