Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would
be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate
that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views.
It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if
you would like to post something on RF Cafe's
Facebook page, please do.
Below are all of the forum threads, including all
the responses to the original posts.
| Yariv3G | Post subject: Why is there a peak at 0 Hz on Spectrum Analyzer Posted: Mon Dec 18, 2006 11:11 am |
|
Joined: Mon Apr 03, 2006 4:06 am
Posts: 8 | Hi,
I am using a spectrum analyzer that has a measurement range from 9kHz up to GHz. When chosing a Start freq at 0Hz and span of 100 MHz, I see a peak from 0 Hz although I don't measure anything (Open).
Has this something to do with the VBW Filter?
I have seen this quite often but never have been asked about this...
Can someone give me a convincing explaination?
Thanks for any hint.
Yariv3G
_________________
R&S RF Application Engineer
|
| | | |  |
| RFTEJerry | Post subject: Posted: Thu Dec 28, 2006 12:46 pm |
| | | | Captain |  |
Joined: Thu Apr 13, 2006 9:53 am
Posts: 17
Location: Florida | The response at 0 Hz is due to the Spec-Ana's LO feedthru. Read Aglient's application note AN150, Spectrum Analyzer Basics for the details.
Godd luck,
RFTEJerry
|
| | | | |
| sm7ovk | Post subject: Posted: Sun Jan 14, 2007 3:11 pm |
| | | | Captain |  |
Joined: Thu Jan 11, 2007 12:59 pm
Posts: 16 | Long time ago since I was at school, but isn't the mathematical explanation that the fourier transform has "problems" with 0Hz?
Regards
Jens
|
| | | | |
| CyberOli | Post subject: Posted: Fri Jan 19, 2007 7:55 am |
|
Joined: Thu Jan 18, 2007 8:09 am
Posts: 12
Location: Belgium | It's not really a "problem", but the Fourrier transform of a 0 Hz signal (direct signal) gives a Dirac Pulse at 0 Hz. If I remember well.
The agilent document given by RFTEJerry is very good to well understand the functioning of a spectrum analyzer.
|
|
Posted 11/12/2012
| 
Kirt
