Hello Robert, I've had identical comments, specifically regarding pre- and compliance applications. I've put all these problems into method's metrology category. Don't you think that it is quite promising technique compared to other alternatives. Best Regards, Vitaly Gorodetsky
> -----Original Message----- > From: Robert Bonsen [SMTP:[email protected]] > Sent: Thursday, May 06, 1999 2:10 PM > To: [email protected] > Subject: RE: Precompliance Testing > > Hi folks, > > The company mentioned, SARA, builds what they call a distributed RF > analyzer named CASSPER. They have been working on it for a while now, > demoed it at a couple of shows, and to the best of my knowledge the system > started to ship recently. In the data sheets I analyzed, mention was made > of background noise cancellation techniques by using two time and > frequency > synchronized receivers, one configured as the "normal" receiver and one as > a reference receiver. The time and frequency sync between the two > receivers > allows for coherent simultaneous measurements of the reference signal and > the measuring signal, hence allowing the system to dynamically reduce the > noise level in the measurement. So far the data sheets... By the way, this > noise cancellation technique will not work on ordinary receivers and > spectrum analyzers because the time/frequency synchronization, which > cannot > be achieved with "ordinary" equipment, is essential. > > In theory this works great, but as with all noise/spurious signal > cancellation techniques (common in the RCS and antenna measurement world) > using a variety of mathematical principles, there will be practical > limitations. Also, one of the drawbacks is that you are required to > purchase another receiver for this technique to work. And of course this > type of receiver with noise cancellation technique is not the kind of > device the standards have made provisions for, so the question is if the > data will ever be acceptable for compliance measurements per the > standards. > > CASSPER is a very interesting device, very useful for a wide variety of RF > applications. I would like to get my hands on one soon to tinker with it > and find out exactly what its potential is. The company mentions as > applications pre-compliance regulatory testing and EUT debugging, but as > indicated it is not usable for compliance testing (yet?). > > Reference: http://www.sara.com/cassper > > Regards, > -Robert > > Robert Bonsen > Principal Consultant > Orion Scientific > email: [email protected] > URL: http://www.orionscientific.com > phone: (512) 347 7393; FAX: (512) 328 9240 > > > --------- > 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).
