Question

A uniform plane EM wave incident normally on a plane surface of a dielectric material is reflected with a VSWR of 3. What percentage of incident power that is reflected?

Answer 1

$|\delta|^{2}=\frac{P_{reflected}}{P_{incident}}$

$P_{reflected}=|\delta|^{2}P_{incident}$

$\delta=\frac{1-|VSWR|}{1+|VSWR}=\frac{1-3}{1+3}=\frac{2}{3}=0.5$

$|\delta|^{2}=0.25$

percentage of incident power that is reflected $=0.25\times 100\%=25\%$