RF power combiners and RF splitters are the same items. The same circuits can be used to combine and split RF power, the only difference being that RF power is applied to one port and extracted from other in the case of the RF splitter, and for the RF combiner, power is applied in the opposite direction.
     Since the 0° power splitter is a reciprocal passive device it may be used as a power combiner simply by applying each signal singularly into each of the splitter output ports.The vector sum of the signals will appear as a single output at the splitter input port.