Directional couplers and power dividers are devices that are prevalent in radio technology. They combine electromagnetic power in transmission lines so signals can be used in different circuits. They only combine power that flows in one direction. Any power that enters an output port is put into an isolated port but will not enter the main signal port. Furthermore, special couplers are available that can equally split power between two output ports, known as hybrid combiners. Read on to learn more about the different types of couplers and dividers.
The most popular combiner is responsible for pairing transmission lines. They are found in a variety of technologies. You may have heard of them as coupled transmission lines or backward couplers.
Similarly, branch-line couplers have multiple parallel transmission lines combined by branch lines between them. The more sections in this type of coupler, the higher the ratio of impedances is. To reduce this, many manufacturers limit these couplers, so they only hold three lines. However, they generally do not have a wide bandwidth. Instead, they are popular because they can handle high amounts of power.
The earliest power dividers were known as T-junctions. These suffer from poor isolation. These three port systems are not very efficient and lead to higher losses as well. However, four-port power dividers have become popular and are much more efficient. You will likely hear these called 90-degree or hybrid couplers and hybrid ring or 180-degree couplers. Additionally, there are other types of dividers which have more than four ports. However, these tend to be inefficient, as well.
Power dividers and directional couplers are common devices in radio technology. Directional couplers are designed to combine electromagnetic power in transmission lines. Meanwhile, power dividers are designed for splitting electromagnetic power. Knowing which types are available can help you figure out what you need.