Subject overview
Gain & Attenuation
Voltage, current and power ratios expressed as gain and attenuation in decibels.
01 Gain & Attenuation
Variables
- I1input current
- Aampere
- I2output current
- Aampere
- ggain
- dBdecibel
- aattenuation
- dBdecibel
- P1input power
- Wwatt
- P2output power
- Wwatt
- U1input voltage
- Vvolt
- U2output voltage
- Vvolt
- Vvoltage / current factor
- 1dimensionless
- Dvoltage / current attenuation factor
- 1dimensionless
Key Formulas
Decibels express logarithmic ratios. Cascaded gains add in dB. The factor 20 for amplitude follows from power being proportional to amplitude squared only when the relevant real impedances are equal.
Positive RMS current, voltage, power and factors. Equal real reference impedances are assumed, so P₂/P₁ = V². Gain g and attenuation a are signed decibel values with a = −g.
Calculate
Type prefixes directly: 1.5k, 250m or 20u. Results: 3 significant figures.
Positive RMS current, voltage, power and factors. Equal real reference impedances are assumed, so P₂/P₁ = V². Gain g and attenuation a are signed decibel values with a = −g.
Enter the required input values to calculate.