Enter the input voltage and the output voltage into the calculator to determine the decibel attenuation.
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Attenuation Formula
The following formula is used to calculate the decibel attenuation (for a voltage ratio, assuming the same impedance at input and output).
A_{dB} = 20\log_{10}\!\left(\frac{V_{in}}{V_o}\right)- Where AdB is the attenuation in decibels (typically positive for loss)
- Vo is the output voltage
- Vin is the input voltage
To calculate the attenuation in dB, take the base-10 logarithm of the input voltage divided by the output voltage, then multiply by 20.
Attenuation Definition
Attenuation is the reduction in a signal’s amplitude or power as it passes through a medium or network (such as a cable, filter, attenuator, or free space), often expressed as a ratio or in decibels.
Attenuation Example
How to calculate an attenuation?
- First, determine the output voltage.
Measure the output voltage.
- Next, determine the input voltage.
Measure the input voltage.
- Finally, calculate the attenuation.
Calculate the attenuation using the formula above.
FAQ
An attenuator is a two-port network (often resistive) designed to reduce a signal level. More generally, attenuation is the reduction in signal level (power or voltage) through a medium or network, and it is commonly expressed in decibels (dB).
Attenuation is commonly expressed in decibels because it represents a ratio of signal levels on a logarithmic scale. The dB scale makes large ranges of ratios easier to work with and allows cascaded losses (for example, multiple stages of attenuation) to be added directly in dB.
