Power dividers and combiners are used in microwave frequencies because of the different behavior of circuits. In microwave frequencies, the modeling of the circuits are different from the expected lumped model. Therefore, power dividers in microwave frequencies are not just resistive power dividers as in the low frequency or DC model.
The important issues while using power dividers, are the specifications or properties of the dividers. In microwave frequency applications, for example power can be reflected from the output ports. Then to avoid the reflected power expected power divider should satisfy the maximum power transfer theory, which says the impedance of the load should be the complex conjugate of the impedance seen from the load end when load is not connected. This is called "matching" of the ports. This leads to transferring maximum power to the load and because of no reflection, avoid to burn out the power supply. Also, again for maximally transfer the power to the output ports, the network should not dissipate power and this property is called "losslessness".
There are three types of dividers :
1. WILKINSON
Wilkinson power divider is a solution of the loss less T-junction problems, which are not matched and non-isolated output ports. The resistive T-junction divider can be a solution for the matching problem but the isolation part cannot be solved and also this solution leads a power loss because of the resistive structure of the resistive T-junction divider. Wilkinson power divider is a lossy three port network and it has a property of being lossless when the output ports are matched. In addition, the isolation between output ports are can be achieved in Wilkinson power divider. Dissipated power in the Wilkinson power divider is from the reflected power. There are two general type of the Wilkinson power dividers; first one is the equal power divider and the second one is unequal power divider.
2. T-JUNCTION
In general, there are two types of T-junction power dividers - lossless and resistive.
3. SPLIT-TEE
Power dividers and combiners are used in microwave frequencies because of the different
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