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Src Leveling, Port Powers, and Attenuators

Question asked by nbaliga on May 20, 2011
Latest reply on May 24, 2011 by Dr_joel
I am using Src Leveling to level powers at the input of a DUT
I will have a high variation in the ripple of the leveling table (0.2 to 4.0 dB or more)
This could be higher if we use src leveling to SHAPE the stimulus to the DUT

The problem I'm having is that if the source power is at the bottom of the PNA range (-27dBm), the PNA does not return an error
It bottoms out at -27 and adjusts the "Port Power" field instead

This is bad for a couple of reasons

1. There is no indication during the sweep that it failed which means we are setting a higher power to the DUT than planned
2. If One point fails, the Port Power is adjusted, and all subsequent points in the sweep will have the NEW Port Power, not the planned port power

so...

A. Is there a mode where the Port Power can be locked and the PNA reports an error if it cannot set the power during the sweep?
B. Is there a mode where the source leveling can auto-range the power for a leveled sweep
   (ie. set the attenuators to accomodate the source leveling table if auto-range is enabled for the port)

I tried setting port 1 to Auto Range but it made no difference, the source leveling still bottomed out and adjusted the Port Power
On the upper end, the PNA source goes unleveled, but it does NOT auto-adjust the Port Power field, which I am okay with because unlike the bottom power case, the PNA can't do anything about it.

We are using FW 9.33.07 on a PNA-B

Appreciate any input you may have!  

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