Noise attenuation

An interference attenuation or filter attenuation is used to quantify the interference suppression effect of interference suppression agents and is usually specified as a function of the frequency . The interference attenuation in d B is calculated, for example, as the logarithmic ratio of the voltages before and after a filter : ${\displaystyle a_{F}}$

${\displaystyle {\frac {a_{F}}{\mathrm {dB} }}=20\cdot lg{\frac {U_{1}}{U_{2}}}}$

The filter attenuation is usually positive.

Related variables are common-mode / differential-mode attenuation, shielding attenuation and the signal-to-noise ratio or the external voltage ratio .

literature

• Adolf J. Schwab, Wolfgang Kürner, Electromagnetic Compatibility, Springer Verlag, ISBN 3-540-60787-0