Power Divider vs. Power Combiner: Understanding the Differences

This page compares power dividers and power combiners, detailing the differences between the two.

A power divider is a device that splits the input power fed into one port into smaller amounts of power across multiple output ports. Think of it like a “T” junction for RF signals.

A power combiner, on the other hand, combines the power fed into multiple input ports and delivers the summed power as output on a single port. It’s essentially the reverse operation of a power divider.

Interestingly, the same RF circuit designed for a power divider can be used as a power combiner simply by swapping the input and output ports. This reciprocity is a key feature of these devices.

The figure below depicts a two-way power divider with a 3-port junction:

With even and odd mode analysis, we can conclude that the power applied at port 1 is divided equally into port 2 and port 3. Additionally, the voltage at ports 2 and 3 lags by 90 degrees with respect to the input at port 1. This specific RF circuit can be used as a 3 dB, 90-degree RF power divider.

The same circuit, as mentioned earlier, can be re-purposed as an RF power combiner by feeding power into ports 2 and 3 and extracting the combined power from port 1.