Enter your target Attenuation (dB) and Characteristic Impedance (Ω) into the Balanced Attenuator Calculator to find the exact Series Resistance (R1) and Shunt Resistance (R2) values you need to build your circuit, along with the resulting Input and Output Impedance.
Series Resistance (R1)
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Shunt Resistance (R2)
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Input Impedance
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Output Impedance
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A balanced attenuator is a circuit that reduces signal amplitude while maintaining impedance matching in differential or balanced transmission systems. It uses matched resistors to provide equal attenuation to both signal paths.
The series resistance R1 = Z0 * (K - 1) / (K + 1) and shunt resistance R2 = Z0 * 2K / (K² - 1), where K is the voltage ratio (10^(dB/20)) and Z0 is the characteristic impedance.
Balanced attenuators work with differential signals and maintain ground isolation, while unbalanced attenuators reference one terminal to ground. Balanced designs are preferred for audio and differential RF applications.
Common impedance values are 50Ω for RF applications, 75Ω for video systems, and 600Ω for audio applications. The calculator works with any impedance value you specify.
Impedance matching prevents signal reflections and ensures maximum power transfer. A properly matched attenuator maintains the system impedance while providing the desired attenuation.
While theoretically unlimited, practical balanced attenuators typically provide up to 40-60dB of attenuation. Higher values may require cascaded stages due to component tolerances and parasitic effects.
Proper attenuation reduces signal amplitude without distortion when impedances are matched. However, it also reduces the signal-to-noise ratio, so the minimum necessary attenuation should be used.
Yes, you should select the nearest standard resistor values (E12 or E24 series). Small deviations from calculated values typically have minimal impact on performance for most applications.