Bias T Calculator

This tool calculates the Capacitor and Inductor values for a Bias Tee design.

Enter the following:

  • Impedance
  • Impedance ratio
  • Frequency of operation


The minimum value of Capacitance is

C = 1/(2*π*f*Xc)

The Inductance value is

L = XL/(2*π*f)


  • f = Frequency of operation
  • Xc = R/n
  • XL = R*n
  • R = Impedance
  • n = Impedance Ratio


This calculator helps determine the Inductor and Capacitor values for a Bias Tee (also known as Bias T). Note that these are minimum values associated with the circuit.

Bias Tees are used to remotely power low noise amplifiers such that they are located close to the antenna.

With either a short cable or no cable between the antenna and amplifier, the antenna cable loss is reduced. This minimizes the noise figure and receiver sensitivity. This in turn maximizes the range of the communication system.