RF Hybrid Combiner, Splitter and Divider
- overview and introduction to RF hybrid combiner / splitter / divider detailing circuits and other essential details.
Although RF power combiners and RF power splitters can be synthesised using resistors, their performance is not optimum as power is lost in the resistors. To overcome this, transformers can be used. These forms of RF power splitters, power dividers and power combiners are known as hybrids.
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.
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.
- 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.
- Complexity: Hybrid power dividers, splitters and combiners utilise transformers and these make them more complicated to manufacture. Careful design of the transformer is required to ensure that the required performance is met.
- 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.
- 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 oft he hybrid. When designing or specifying a hybrid combiner, splitter or divider, the frequency response needs to a prime consideration.
By Ian Poole
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