To use this tool, enter the desired value of dB attenuation and the characteristic impedance (default value is 50 ohm). The tool computes resistor values in different configurations:
- Pi Attenuator
- T Attenuator
Table of Contents
Table of Contents
Pi Attenuator Calculator
![](https://i0.wp.com/www.onesdr.com/wp-content/uploads/2022/11/Pi-Attenuator.jpg?resize=580%2C326&ssl=1)
Formula
R1 = Zo [10dB/20 + 1] / [10dB/20 – 1]
R2 = Zo/2 [10dB/10 – 1] / [10dB/20]
where R1 is the shunt resistor (to ground) and R2 is the series resistor. To build this attenuator you will need
- two shunt resistors – one at the input and the other at the output
- one series resistor
T Attenuator Calculator
![](https://i0.wp.com/www.onesdr.com/wp-content/uploads/2022/11/T-Attenuator.jpg?resize=770%2C433&ssl=1)
Formula
R1 = Zo [10dB/20 – 1] / [10dB/20 + 1]
R2 = (2*Zo)*[10dB/20] / [10dB/10 – 1]
where R1 is the series resistor and R2 is the shunt resistor (to ground). To build this attenuator you will need
- two series resistors – one at the input and the other at the output
- one shunt resistor