This calculator determines the value of resistor R1 necessary to design a balanced attenuator from the desired attenuation (in dB) and the characteristic impedance (Z0). It helps create precise attenuation networks to balance RF or audio signals.
Ideal for RF engineers, circuit designers and audio technicians who need to adjust power or amplitude levels without mismatching the system.
Formula
R1 = Z0 × [1 / (10^(dB/20) – 1)]
Explanation of the formula
- Z0 is the characteristic impedance of the system, typically 50 Ω.
- dB represents the desired attenuation value.
- The formula calculates the resistance R1 needed to reduce the signal while maintaining impedance matching.
- A balanced design ensures symmetrical attenuation on both sides of the differential signal.
10 dB balanced attenuator 50 ohm
Input : Attenuation = 10 dB, Z0 = 50 Ω
Output : R1 ≈ 5.89 Ω
Benefits and uses
- Enables rapid design of precise balanced attenuators.
- Maintains impedance matching to avoid reflections.
- Useful for testing, calibrating or balancing RF and audio signals.
- Facilitates controlled reduction of signal level without distortion.