Digital connections have outgrown cables and cords with the rise of wireless connectivity expanding demand for things like automotive electronics, cellular communications, and the Internet of Things. These applications are being run on RF signals, their components, and subsystems. However, there are times where the signals need to be directed to more than one application at a time or an application depends on a combination of multiple signals.
Splitting the Signal
When splitting or combining an RF signal, there can be challenges with the accuracy of delivery. The designers have to establish a signal routing quality that prevents the degradation which occurs from loading difficulties or mismatches. These adaptors must stay within the budget constraints and maintain critical size. To ensure the signal (when split or combined) for both input or output is accurate and strong, designers turn to RF power dividers. These devices, also known as RF combiners when used in reverse, are useful for maintaining the full load impedance to all of the different applications or sources, in addition to meeting isolation needs.
Understanding RF Combiners
There are three commonly used types of RF power combiners: Wilkinson, hybrid, and resistive. Designers make their choice in accordance with the needs and specifications of applications, following important implementation considerations.
A power divider has one input signal but two or more output signals. A designer may try to use a “tee” connection to divide a signal into two separate but reduced amplitude components. Though this may work, it is subject to several limitations. The primary concern is impedance mismatch. The second problem is with isolation, as when one of the outputs short-circuits, the other port is also shorted.
The need for consistent signal delivery, particularly when running multiple applications, can be met when the right products are selected for the job. Knowing the characteristics of the different RF divider types can aid designers in choosing the method.