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Using Uncalibrated S21 FIFO data from PNA for antenna measurements

Question asked by bfris001 on Aug 8, 2018
Latest reply on Aug 8, 2018 by johanericsson

fifo I have a N5224A PNA with Opt 118. I'm going to use it for measuring antenna patterns on my antenna range. To make things run very fast, it would be nice to use the FIFO feature which allows me to shove data into memory and retrieve it later. However, in FIFO mode, the data stored is uncorrected/uncalibrated. The user is supposed to correct the data later somehow.

 

For antenna range measurements, the principle thing to measure is S21 -- usually magnitude but sometimes phase is also important.

 

According to Keysight Application Note AN 5965-7709, PNAs use a 12 parameter error correction scheme. But to get corrected S21, I also have to measure S11, S22, and S12. Is it even possible to put all four S parameters into the FIFO? And how many sweeps would I have to do (assuming I'm running the PNA in sweep mode and not CW) to get all four S parameters?

 

As an alternative approach, it seems like I should be able to take a REFERENCE frequency sweep with a known antenna and use that to correct S21 data. At least I think that would work fine for S21 magnitude. I'm not sure what to do with phase in this scheme. Maybe I have to abandon getting that information in FIFO mode. Are there any other pitfalls to this scheme?

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