Power dividers (also power splitters and, when used in reverse, power combiners) and directional couplers are passive devices used mostly in the field of radio technology. They couple a defined amount of the electromagnetic power in a transmission line to a port enabling the signal to be used in another circuit.There are wilkinson power splitter and cavity power splitter or reactive Power Splitter.
The Wilkinson power divider / Wilkinson combiner uses quarter wave transformers to split the input signal to provide two output signals that are in phase with each other. The resistor between the two output ports enables the two outputs to matched while also providing isolation.
In the field of microwave engineering and circuit design, the Wilkinson Power Divider is a specific class of power divider circuit that can achieve isolation between the output ports while maintaining a matched condition on all ports.
Reactive Power Splitters consist of single input and multiple (two or more) outputs. Those with an odd number of output ports are called as N way power splitters. They are ideally used for high power cellular applications.