Quarterwavetransformaattori
Quarterwavetransformaattori, known in English as the quarter-wave transformer, is a short section of transmission line of electrical length one-quarter of a wavelength (λ/4) used to match impedances between a source and a load at a specific frequency. The design uses a line with characteristic impedance Z0 chosen to transform the load ZL into the source impedance ZS.
For a lossless line of length λ/4, the input impedance is Z_in = Z0^2 / Z_L, so to achieve
Limitations: The transformation is highly frequency dependent and most effective near the center frequency; small deviations
Implementation notes: Quarter-wave transformers can be realized with coaxial lines, microstrip, or stripline and are common