The Balanced Attenuator conversion calculator determines the resistor value R1 needed to achieve a specific attenuation level for a given characteristic impedance. It is widely used in RF and microwave circuits to maintain signal balance while reducing signal power. This design is preferred for symmetrical systems where impedance matching and isolation are critical.
Formula
R1 = Z0 * [ 1 / ( 10^(dB/20) – 1 ) ]
Formula Explanation
- Z0 is the system’s characteristic impedance, typically 50 Ω or 75 Ω.
- dB is the desired attenuation level expressed in decibels.
- The formula ensures a balanced configuration that provides equal attenuation on both signal lines.
- Maintains impedance matching between source and load to prevent reflections.
Uses of this calculator
- Designing balanced attenuators for RF and audio applications.
- Setting specific signal reduction levels without disturbing impedance balance.
- Improving isolation in differential amplifier circuits.
- Testing or calibrating signal levels in balanced transmission systems.
What is the resistor value for a 10 dB balanced attenuator in a 50-ohm system?
Input: Attenuation = 10 dB, Z0 = 50 Ω
Output:
- R1 = 50 * [ 1 / (10^(10/20) – 1) ] = 50 * [ 1 / (3.162 – 1) ] = 50 * (1 / 2.162) = 50 * 0.462 = 23.1 Ω
- Required resistor value (R1) = 23.1 Ω