In message <[email protected]>, dated Wed, 21 Mar 2007, Daniel Liang <[email protected]> writes:
>Does anyone know about the what is the difference between "reference >bandwidth" and "measurement bandwidth" for a "transmitter spectrum >mask" measurement by a spectrum analyzer ? > >I read the standard which mentioned the "reference bandwidth" referred >to CISPR 16-1 but I cannot find it. CISPR 16-1 has been split up into sections. The definition is there somewhere. For broadband emissions, it's obvious that any limit value has to be associated with a specified bandwidth, because the measured level increases as the bandwidth increases. So 'reference bandwidths' (for different frequency ranges) are specified in CISPR 16-1-1: 9kHz to 150 kHz - 200Hz 150 kHz to 30 MHz - 9 kHz 30 MHz to 1 GHz - 120 kHz Above 1 GHz - 1 MHz The 'measurement bandwidth' is the bandwidth you actually use for the measurement. Usually, it's the same as the reference bandwidth, but in the case you cite, and some others, you have to use a different bandwidth to get a meaningful result. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk There are benefits from being irrational - just ask the square root of 2. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
