The short answer is, yes. A RF splitter and combiner are the same passive network devices, and to use a splitter as a combiner, the input signals are placed in the combining ports of the splitter, where the combined output is then available at the splitter input port. Typically, power divider/combiners are designed and packaged in such a way that the splitter input port/combiner output port are clearly designated as isolated (often on the opposite side of the package) from the splitter output ports/combiner input ports. With surface mount technology (SMT) or highly compact divider/combiners, the ports may be less clearly designated, but port designations should be clearly labeled or otherwise indicated in the documentation.
In many applications, a power divider/combiner is used for both functions. An example of this is with a phased array antenna system that uses a hybrid or analog architecture. With these architectures the RF source is divided, and that energy is split to several antenna elements with phase shifters and possibly attenuators during transmission. During reception, the phase shifted energy is combined through the power combiner and sent to the receiver.
As power divider/combiners are non-ideal passive networks, there is some insertion loss and imperfect isolation between the ports. Amplitude and phase balance are also a common electrical specification parameter for RF power divider/combiner components. Lastly, a given power divider/combiner circuit will typically only operate over a set frequency range, with a finite bandwidth less than that of the interconnect interface used in the packaging of the component.
What Is the Difference Between RF Splitters & Combiners?
RF Splitters and Combiners are called by many names in the industry, of which, some of the nomenclature follows how the parts happened to be used in a given signal chain. RF Power Combiners are typically the same exact component as an RF Power Splitter or RF Power Divider. RF splitters are also referred to as RF dividers or dividers/combiners, or even combiner/dividers. The majority of RF splitters/combiners are passive reciprocal networks. This means that for an RF power divider/combiner there are no active components and no additional power supplied to the divider/combiner outside of what is contained in the input signal.
There are some circuits that perform power splitting/combining functions that may include active elements and may be nonreciprocal. However, the terms power combiner, divider, and splitter most often refer to passive reciprocal networks, and are all the save device that performs a combining or dividing function depending on the orientation of the component in the signal chain.