Reflection and transmission coefficients


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Reflection and transmission coefficients

When an electromagnetic wave passes from a medium of permeability μ1 and dielectric constant ε1 to one with values μ2 and ε2, part of the wave is reflected at the boundary and part transmitted. The ratios of the amplitudes in the reflected wave and the transmitted wave to that in the incident wave are called the reflection and transmission coefficients, respectively. For oblique incidence, the reflection and refraction formulas of optics are most convenient, but for normal incidence of plane waves on plane boundaries, such as occur with transmission lines, waveguides, and some free waves, the concept of wave impedance and characteristic impedance is useful. See Electromagnetic radiation