Hybrid RF Combiner, Splitter / Divider

Hybrid RF combiner / splitter/ divider circuits have the advantages of lower loss over their resistive counterparts.

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RF Combiner Splitter Couplers & Hybrids Includes:
Combiner, splitter, coupler hybrids overview Splitters & Combiners Resistive splitter & combiner Hybrid splitter & combiner Wilkinson splitter & combiner Directional coupler

Hybrid RF combiner-splitters enable much higher levels of performance to be achieved than with simple resistive elements.

The splitter-combiners that use resistors introduce additional loss as a result of the resistors used. When hybrids are used, it is possible to reduce the power lost as heat to relatively low levels.

This means that hybrid combiner-splitters are used where performance is an issue, although cost and difficulty of design are greater.

The names, RF splitter hybrid, divider hybrid or combiner hybrid all refer to the same types of element - power dividers and power splitters being the same name fort he same function and a power combiner is the reverse of a splitter.

Typical microwave connectorised 4-way splitter / combiner — Typical commercially available microwave 4 way splitter / divider

Hybrid splitter, divider, combiner advantages and disadvantages

As may be imagined, hybrid splitters and hybrid combiners have a number of advantages and disadvantages. These need to be considered when deciding what form of splitter /divider / combiner to use or design into some equipment.

Hybrid splitter combiner advantages

Loss: Using hybrid splitters / hybrid dividers / hybrid combiners, much less power is lost than if a resistive function had been used. When used as a splitter or divider the main level reduction is caused by the action of dividing the power between several ports. Some power will be lost in the hybrid - transformer - but this is often low.

Hybrid splitter combiner disadvantages

Complexity: Hybrid power dividers, splitters and combiners utilise transformers and these make them more complicated to manufacture. Careful design of the transformer along with careful manufacture is required to ensure that the correct performance is obtained.
Frequency response: The frequency response of many hybrid splitters, hybrid dividers and hybrid combiners is more limited than their resistor based counterparts. Transformers have limited frequency ranges and this limits the overall range of the hybrid. When designing or specifying a hybrid combiner, splitter or divider, the frequency response needs to a prime consideration.
Cost: Using transformers, hybrid combiners, hybrid dividers or hybrid splitters are more costly - transformers require careful construction and are considerably more complicated than resistors which are widely available and cheap.

Hybrid splitter / combiner circuits are always used where loss is an issue. They are able to provide little resistive power loss and as a result they are far more efficient. Careful design is needed because they incorporate transformers and this typically limits their frequency response and it can also provide some issues with impedance matching. However the technology used these days means that the performance is normally very good.