Quarter Wave Transformer Impedance Conversion Calculator

Ω
Ω
Ω

The Quarter Wave Transformer Impedance conversion calculator computes the required characteristic impedance of a quarter-wave section used to match two transmission lines with different impedances. This technique minimizes reflection and ensures maximum power transfer between components in RF and microwave systems.

Formula

Z₀ = √(ZL × Zin)

Formula Explanation

  • Z₀ is the characteristic impedance of the quarter-wave transformer.
  • ZL is the load impedance connected at the end of the transformer.
  • Zin is the input impedance of the source transmission line.
  • The transformer length is one-quarter of the operating wavelength (λ/4), which inverts impedance to achieve a match between ZL and Zin.

Uses of this calculator

  • Designing impedance matching sections in RF transmission lines.
  • Reducing signal reflections and improving power transfer.
  • Matching antennas, amplifiers, or filters to transmission lines.
  • Optimizing performance in microwave and high-frequency circuits.

What is the quarter-wave transformer impedance for 50 ohm to 100 ohm matching?

Input: Zin = 50 Ω, ZL = 100 Ω

Output:

  • Z₀ = √(50 × 100) = √5000 = 70.71 Ω
  • Required Transformer Impedance = 70.71 Ω