In Power Dividers

We get this question a lot: how much power can part XYZ handle?

Power handling is a difficult topic, because the ways in which a device can fail depend so much on the operating conditions that it is subjected to.

We specify the max power on (for example) the PD-0165 as 1 watt only to be extremely conservative. Here are some use scenarios for the PD-0165 and the power handling I would estimate:

– Ideal use case: 50 ohm matched at all ports, using the device as a power divider. In this case the device is only dissipating the excess insertion loss. Depending on the heat sinking it has attached, it should be able to handle 10s of watts of CW power or more at 43 GHz. At a high enough power the connectors will fail.
– Worst case CW performance: Out of phase reflections at both output ports, or use as a power combiner with two signals that are 180° out of phase. In this case all the power will be dissipated in the isolation resistors, which means that the power is limited to what the resistors can dissipate. This is where the power handling will be limited to about 1 W before the resistors pop.
– Pulsed case: In this situation the power is limited by the voltage breakdown in the device. If the peak power is high enough the voltage will break down the dielectric either in the connectors or the substrate, this isn’t clear. The amount of power it can take depends on the pulse width and hence the peak power.

So the amount of power that you can put through the device depends on how you are using it and how much heat sinking you provide to it.

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