John, Interesting question that you have posed. A few years ago, I submitted a product to the FCC that required average detection. It seemed that the FCC had a certain distrust of the implementation of average detectors by various manufacturers. The data that I was submitting was for a system that was pulse modulated. The FCC required a "mathematical average" based on duty cycle instead of allowing the average detection of the spectrum analyzer. It was simple enough to do for our product so I did not fight it. Just thought I might raise a caution flag.
Don Umbdenstock Sensormatic > ---------- > From: Scott Douglas[SMTP:[email protected]] > Reply To: Scott Douglas > Sent: Wednesday, September 08, 1999 8:08 AM > To: '[email protected]'; [email protected] > Subject: RE: Average Measurements above 1 GHz > > > John, > > MY HP 8591EM will in fact perform average measurements. The manual makes > specific reference to CISPR 11 and CISPR 16 for compliances. The analyzer > is rated to 1.8 GHz. The HP 8593 series goes even higher. > > Scott > [email protected] > > -----Original Message----- > From: [email protected] [SMTP:[email protected]] > Sent: Wednesday, September 08, 1999 4:37 AM > To: [email protected] > Subject: Average Measurements above 1 GHz > > > I recently put out a question on measurements above I GHz. I got several > replies for which many thanks. > > The recommendations were to try several suppliers for pre-amps. These > included HP 8449, Miteq (low noise amps) and TEC in Mountain View. > > We actually used two Mini Circuits preamps in series which have enabled us > to gain the necessary gain and noise figure. > > Now that we can carry out measurements at 3m I have another question. How > to perform average measurements above 1 GHz. > > Most analyzers do not appear to have a specific CISPR compliant average > function. So how is the average measurement carried out? > > Use of the average detector could yield a few dB lower levels even for a > narrowband emission. > > As a point of information I note that the proposal for CISPR 22 > measurements > above 1 GHz does not allow the use of an average detector. This could > pose > eventual problems for manufacturers as it represents a considerable > tightening on the current FCC limits. > > I would be most grateful for any information on carrying out compliant > average measurements. > > Regards > > John Cronin > > > > ______________________________________________________ > Get Your Private, Free Email at http://www.hotmail.com > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to [email protected] > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to [email protected], > [email protected], [email protected], or > [email protected] (the list administrators). > > > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to [email protected] > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to [email protected], > [email protected], [email protected], or > [email protected] (the list administrators). > > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
