RF power splitters and combiners are essential components in RF engineering. They play a key role in wireless communication systems, test and measurement equipment, and other applications that require signal distribution or synthesis. These two devices can not only be used as independent units, but can also work inversely in some cases10

　　. The following will discuss in detail the working principle, types, and application scenarios of RF power splitters/combiners.

　　1. RF Power Splitter

　　1.1 Basic Concepts

　　A power splitter is a multi-port network that can distribute an input signal to two or more output ports in a certain proportion. Ideally, if it is a power divider that divides equally, the power on each output port will be half of the input power minus 3 dB (i.e., power loss). The splitter ensures good isolation between all output ports and is usually designed so that there is no reflection at the input port when all output ports are connected to matched loads2

　　.

　　1.2 Types and characteristics

　　Resistor type: Three equal resistors are used to form a star configuration, which is suitable for broadband applications but has large insertion loss.

　　Wilkinson type: By introducing a terminal resistor to achieve good port-to-port isolation, it has low insertion loss and is suitable for narrowband applications.

　　Hybrid type: Combining the advantages of transmission lines and resistors, it can provide better performance over a wider frequency range, such as branch line directional couplers. In addition, there are some special power dividers that can provide controlled phase shift between output ports7

　　.

　　1.3 Application areas

　　Splitter is widely used in phased array antenna systems, where a single RF source is evenly distributed to multiple antenna elements; in addition, in the orthogonal demodulator, the local oscillator also needs to provide in-phase and quadrature component signals for the two mixers. In addition, for situations where comparative measurements are required, the power divider can provide good impedance matching at the two output ports, facilitating the measurement of different properties of the two output signals1

　　.

　　2. RF Power Combiner

　　2.1 Basic Concepts

　　The power combiner is the opposite of the splitter. It can receive multiple input signals from different sources and combine them into one output signal. To ensure the quality of the output signal, the combiner must correctly handle the relative amplitude and phase relationship between the input signals to avoid unnecessary interference or distortion. At the same time, it is also necessary to consider how to effectively manage heat dissipation, because the energy of multiple input signals will be concentrated at the output end2

　　.

　　2.2 Types and Features

　　Passive combiner: mainly composed of passive components such as inductors, capacitors and transmission lines, with a simple and stable structure, but may cause certain insertion loss.

　　Active combiner: contains active components such as amplifiers. Although it increases complexity and cost, it can provide gain and improve isolation2

　　.

　　2.3 Application Examples

　　In a multi-carrier power amplifier, a combiner is used to combine signals from different channels into the same power amplifier for amplification before transmitting. Another example is in the base station receiving section, where the outputs of multiple low-power receivers can be combined through a combiner and then sent to the subsequent processing unit. It is worth noting that some combiners also support reverse operation, that is, they can be used as splitters10

　　.

　　3. Difference between power dividers and splitters

　　Although the names of power dividers and power splitters sound similar, and both can divide one signal into two or more signals, there are differences in internal structure and technical details. For example, the resistor structure used to separate power inside them is different, which may lead to different performance in actual applications9

　　. However, in many literatures and practices, the two terms are often used interchangeably, especially when describing products with the same function10

　　4. Selection Guide

　　When selecting a suitable RF power splitter or combiner, the specific needs of the system should be considered, such as the operating frequency range, the required maximum power handling, the expected insertion loss level, and whether additional functional characteristics (such as polarization maintenance) are required. In addition, it is also necessary to check the product's electrical specification sheet to ensure that the selected product meets your project requirements13

　　. For example, in RF testing, choosing the right splitter or combiner depends not only on its basic parameters, but also on ensuring good impedance matching between ports to reduce measurement uncertainty8

Read recommendations:

radial power combiner

mimo omnidirectional antenna

mini circuits filter

How to maintain microwave level switch RF sensor.philmac universal transition coupling

waveguide power combiner