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IQ Analyzer file format & power calculations

Question asked by ryan_mccourt on Aug 5, 2013
Latest reply on Aug 5, 2013 by tabbott
I'm trying to pull IQ data out of an EXA for post-processing. I've managed to capture the I/Q samples and dump them to a file (example attached), but have two questions:

1 - The file format doesn't seem to be described in the IQ Analyzer documentation (http://cp.literature.agilent.com/litweb/pdf/N9060-90029.pdf). Is there somewhere that documents the file format?

2 - It looks like the I/Q data is stored in volts, with I and Q values alternating in the first column. However, when I try and use that data to compute the sample power, I get a result that is off by 3.01 dB, relative to the known input power, and the value reported in the third column. I'm using 10*log10((I^2+Q^2)*1000/50) to get the value in dBm - is there something else that the EXA has to take into account when calculating the power for each sample?

Thanks -  

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