The primary difference between reactive power combiners and power combiners with isolation is what happens when signals are fed to the combiner inputs that are not perfectly matched in amplitude and/or phase. In an isolated combiner, the amplitude and/or phase error is terminated in a resistive network whereas reactive combiners reflect non-coherent signals back to the inputs. Reactive combiners are less complex and can be made lower loss and thus more efficient in applications where the sources can be protected with isolators or other means.
