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E5052B Signal Source Analyzer Frequency Counter Resolution

Question asked by steveor on Jun 11, 2013
Latest reply on Jul 1, 2013 by steveor
Hi,

From the datasheet at:
http://cp.literature.agilent.com/litweb/pdf/5989-6388EN.pdf
it seems the frequency resolution of the E5052B is one of three settings: 10Hz, 1kHz, or 64kHz.

My program sets the resolution with the SCPI command:
:SENSE:FP1:FREQ:RESOLUTION NARROW (my choices are NARROW, MIDDLE or WIDE)

But this seems to give me a resolution of 1 KHz, not the expected 10 Hz. Also the programming guide says the Frequency Resolution is 1KHz or 64KHz.

By the way, I posted this question to the wrong forum yesterday.  Perhaps this is why I didn't get any responses.

In addition, I'm adding some more information as to why I think the resolution seems too coarse.  Here's a description of an experiment I performed.  First, I measured about 1300 oscillators running at 2.608 GHz on a wafer with a wafer prober and dumped out the frequency to 1 Hz resolution.  Then, I repeated the run and compared the results.  When I analyze the results, I see the die by die change in frequency (dF) is quantized and the numbers correspond to binary numbers with 8 bits or greater.  That is, dF can be 0, 256, 512, 768, 1024, and so on.  The negative frequency shifts are similar.  Please see the dF histogram attached.  You can clearly see the quantized levels.

These oscillators do not have a digital system included, that is no dividers, multipliers, or anything like that, so I don't expect this is coming from my device under test.

The datasheet says the resolution is 10 Hz in fine mode, which I've selected.  In addition, the uncertainty claims to be +/- (resolution +/- timebase uncertainty).  I'm using an external timebase with better than 100 parts per billion accuracy, so that should be negligible in the uncertainty calculation. 

It is possible there's something wrong with my Signal Source Analyzer?  It seems either the resolution or uncertainty description of the instrument is incorrect.  Am I missing something?

Thanks,
Steve Ortiz

RF Test Development Engineer
Wireless Semiconductor Division
Avago Technologies  

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