This paper presents the design and simulation of a Chireix combiner that will form part of an “outphasing” system. With the application of this technique we should obtain an improvement of the efficiency of the amplifier versus back-off, which will allow us to operate in a more linear region without losing efficiency. We prove that this is not always true and that the success of this technique depends on multiple factors such as the type of input signal, the type of amplifier and the design of the Chireix combiner. The comparison of the results of a class D and a class AB amplifiers is made, achieving a high improvement in efficiency in the case of the first one, which maintains a value of 90% until a back-off of -6 dB, but not so good in the second case due to the own characteristics of the amplifier
