# skrf.media.rectangularWaveguide.RectangularWaveguide.alpha_c¶

RectangularWaveguide.alpha_c

Loss due to finite conductivity and roughness of sidewalls

In units of np/m See property rho for setting conductivity.

Effects of finite conductivity are taken from [1]. If roughness is not None, then its effects the conductivity by

$\sigma_c = \frac{\sigma}{k_w^2}$

where

\begin{align}\begin{aligned}k_w = 1 + e^{(-\delta/2h)^{1.6}}\\\delta = \mbox{skin depth}\\h = \mbox{surface roughness }\end{aligned}\end{align}

This is taken from Ansoft HFSS help documents.

References

 [1] Chapter 9, (eq 9.8.1) of Electromagnetic Waves and Antennas by Sophocles J. Orfanidis

http://eceweb1.rutgers.edu/~orfanidi/ewa/