Active broadband impedance transformations using distributed techniques

An active circuit design technique which allows impedance transformations over extremely broad bandwidths, using distributed impedance transformation amplifiers, is described and demonstrated. The transformation is obtained by coupling two or more identical distributed amplifier circuits in parallel by the use of a common input or output line. The circuit technique can be used where broadband impedance matching is important, such as for laser diode drivers or antenna matching in broadband receivers and transmitters. The circuit technique is demonstrated by a fabricated amplifier that gives a 1:2 impedance transformation over a 2- to 20-GHz bandwidth.<>