Before revision: A quarter-wave impedance transformer, often written as λ/4 impedance transformer, is a component used in electrical engineering consisting of a length of transmission line or waveguide exactly one-quarter of a wavelength (λ) long and terminated in some known impedance.
After revision: A quarter-wave impedance transformer, often written as λ/4 impedance transformer, is a component used with electrical engineering consisting length of transmission line or waveguide exactly one-quarter of a wavelength (λ) long and terminated in some known impedance.