Quarter Wave Transformer Impedance Calculator

A quarter wave transformer is used to match two transmission lines with different impedances. As the name suggests, the length of this transmission line if fixed at a quarter of the wavelength (λ/4).

Result

  • Characteristic Impedance ((Zo)
    Ohms
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Derevation of the Quarter Wave Transformer Equation

A quarter wave transformer is used to match two transmission lines with different impedances. As the name suggests, the length of this transmission line if fixed at a quarter of the wavelength (λ/4). The wavelength can be calculated based on frequency here.

quarter Wave formula 1

The input impedance of a transmission line of length L with characteristic impedance Zo and connected to a load with impedance Z­­L:

Quarter Wave 2

When the wavelength is take to be a quarter wave (λ/4). This formula simplifies down to:

Quarter Wave 4

The Characteristic Impedance of Transmission Line is then given by:

Quarter Wave Formula