Resistive Power Splitter/Divider
Features
Wide bandwidth operation
SMA and MMCX connectors
Typical Characteristics
Some words about how the S-parameter measurements were made and possible constraints and limitations due to that.
Divider
Figure 1: Resistive divider frequency characteristics.
Splitter
Figure 2a: 0805 resistive splitter frequency characteristics.
Figure 2b: 1206 resistive splitter frequency characteristics.
Applications Information
The following is taken from an HP seminar note: Choosing and Using Resistive RF Power Splitters.
Using two resistor splitters for RF source matching
Figure 3: Effects of source and load variations in leveling applications.
You can optimise RF source match by keeping the effective source output power constant through a two-resistor power splitter and a leveling loop or ratio meter. In this application, port 3 of the power splitter becomes the effective source output. The resistive symmetry of the two-resistor splitter divides the source power equally between the input port 1 and reference arms. Both arms experience the same variation in input power, so the leveling loop correctly compensates for any changes in the source output power. When the load at the effective output port 3 is not perfectly matched (Figure 3), a portion of the source power reflects back into the power splitter. The power re-reflected by the two-resistor power splitter equals the power transmitted to the reference arm. Thus any change in output power caused by the load reflection is equally seen in the reference arm, allowing the leveling loop to correctly compensate for these variations - which is why the two-resistor splitter is the right choice for this application.
Three resistor splitters for power division applications
Figure 4: Compare two- and three-resistor splitter in this power-division application. The three-resistor splitter is clearly the right choice.
Figure 4 compares the performance of two- and three-resistor splitters in a power division measurement. When Figure 3 compares the perfomlance of two- and three-resistor splitters in a power division measurement. When ports 1 and 2 are loaded with a 50 ohm characteristic impedance, the two-resistor splitter presents an 83 ohm impedance to port 3 load - a poor output power match. In contrast, the three-resistor power splitter presents a 50 ohm impedance to port 3 load, dividing the power equally and providing a good impedance match at each ofthe input and output arms.