Dear all experts, 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. Below is the description from the standard. Regards,
Daniel Liang Annex C (informative): Determination and use of the measurement bandwidth CISPR 16-1 [3] specifies a reference bandwidth for the measurement of unwanted emissions by measurement receivers and spectrum analysers. The reference bandwidth (BWREFERENCE) cannot always be used as the measurement bandwidth (BWMEASUREMENT). This is particularly the case if the measurement is to be made for example on the slope of a spectrum mask or a receiver selectivity curve. In such situations the measurement shall be made with a sufficiently low bandwidth in order not to distort the reading. The actual measured value, A, shall be referred back to the reference bandwidth by either: Correcting the measured value, A, for any signal having a flat level spectrum with the following formula: B= A + 10* log ( REFERENCE BW / MEASURED BW) Where: - B is the measured level, A, transferred to the reference bandwidth; or - Use the measured value, A, directly if the measured spectrum is a discrete spectral line. A discrete spectrum line is defined as a narrow peak with a level of at least 6 dB above the average level inside the measurement bandwidth. <http://cn.mail.yahoo.com/?id=77072> _____ Do You Yahoo!? 捇誥轎煤G蚘眊ㄜ笢弊菴珨橈拸嶼僵蚘璃玊閉湮蚘眊 <http://cn.mail.yahoo.com/?id=77071> - ---------------------------------------------------------------- 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 emc-p...@ieee.org 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 emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com 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 ______________________________________________________________________
