YUGUANG's Tee Attenuator (T-pad) Calculator helps you determine the resistor values (R1 and R2 in ohms) for designing a Tee attenuator. Simply enter the desired attenuation (dB) and the characteristic impedance of the transmission lines, and the calculator will provide the required resistor values for proper signal attenuation and impedance matching.
Enter your parameters below to calculate results.
The T-pad Attenuator (or Tee Attenuator) is a passive resistive network used to reduce signal power while maintaining impedance matching. As its name implies, the circuit topology resembles the letter "T".
Circuit Structure: A standard symmetrical T-pad consists of three resistors:
This calculator computes the required resistor values ( and ) based on the desired attenuation () and the system characteristic impedance ().
1. Calculate the K-factor: First, determine the voltage ratio () from the decibel value:
2. Calculate Resistor Values: Once is found, substitute it into the following equations:
Series Resistors ():
Shunt Resistor ():
Where:
Why use a T-Pad? Attenuators are essential in RF (Radio Frequency) design for two main reasons:
Topology Advantage: The T-pad is favored for its simplicity. Compared to complex "Bridged-T" or "Balanced" networks, the T-pad is easier to manufacture, especially when etching thin-film circuits or laying out PCBs for high-frequency applications.