Medium of small loss - wykład

Medium of small loss We say the medium has small loss when σ ¿ ω² i.e. conduction current ¿ displacement
current. Then the above two equations can be put into the approximate forms
α ≈
σ
2
r
μ
²
(9.7)
i.e. half the product of the conductivity and wave impedance for a lossless medium,
β ≈ ω√μ² (9.8)
and
η ≈
r
μ
²
. (9.9)
The last two equations are the same as for a lossless medium. The approximations
being used here are a little less accurate than those quoted in Reference 1, wherein second
order corrections to β and η are provided, but the expessions quoted here are well suited to
both practical application and the furter theoretical development found in later chapters.
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