The design of an RF‐power amplifier using the distributed network synthesis in order to achieve the required performance over an operating frequency range is presented. The transfer function of distributed matching circuits, which are useful for the design of RF‐power amplifiers, is derived using an equal ripple approximation. Element values of the network used to match device models are calculated in terms of minimum insertion losses and ripples for a specified network topology. To verify the performance of synthesized circuits, the results are applied to the design of an RF transistor power amplifier with an appropriate device‐modeling technique. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 207–211, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11171