AnsweredAssumed Answered

MXA FFT mode spurs

Question asked by wheel on Jun 25, 2007
Latest reply on Jul 6, 2007 by wheel
Currently our company is evaluating the new MXA and after some short testing, we found some internal spurs showed up in low frequency under FFT mode. (ie. center 15.4Mhz, span 25Mhz, RBW 1k, FFT 25Mhz).   Our experiment was done with terminator, and the spurs are at least 10db higher noise floor.  (the case above is not the worst case, we saw more serious ones)   We double checked with VSA connected with MXA and turned out the same result.   Also, the spurs will change in some frequency pattern when changing the center.  So it is more like internal LO mixing product.  However that did not happen on Sweeping mode.   

The initial response from local representatives stating that this is not a issue and claim the MXA in FFT mode only reach -100dbm.   Maybe I am wrong, but someone can show me why an internal spurs is not an issue, and where the -100dbm comes from.

... wheel