What is the formula for Attenuation Factor (K)?

The Attenuation Factor (K) formula is K = 10^(dB / 20) (voltage ratio), where K—Voltage attenuation ratio (input/output); dB—Attenuation in decibels.

What does K mean in the Attenuation Factor (K) formula?

K is Voltage attenuation ratio (input/output).

Attenuation Factor (K)

Q: How do you calculate Attenuation Factor (K)?

Use the formula K = 10^(dB / 20) (voltage ratio). The attenuation factor K is the linear voltage ratio corresponding to a decibel attenuation, and it is the quantity that all resistive-pad design equations use. Enter the values you know in the calculator above and it solves for the remaining variable.

K = 10^(dB / 20)

Calculator

Voltage Ratio K

Attenuation

Result

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Formula

K = 10^(dB / 20) (voltage ratio)

Description

The attenuation factor K is the linear voltage ratio corresponding to a decibel attenuation, and it is the quantity that all resistive-pad design equations use. A 6 dB pad has K ≈ 2 (halves the voltage), and a 20 dB pad has K = 10. Converting the desired dB loss to K is the first step in designing any T, Pi, L, or bridged-T attenuator.

Variables

K — Voltage attenuation ratio (input/output)
dB — Attenuation in decibels

Practical Notes

For a power ratio use K = 10^(dB/10). K is always ≥ 1 for an attenuator; the pad resistor formulas below all take this K.

Related Concepts

All Attenuators & Pads formulas →

Attenuation Factor (K) T-Pad Series Resistor T-Pad Shunt Resistor Pi-Pad Series Resistor Pi-Pad Shunt Resistor Bridged-T Bridge Resistor Bridged-T Shunt Resistor

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