Yes, it can get complicated. However, we don't HAVE to get involved with the complications. (We can if we want to.)
What I described is a coupled resonant notch filter, familiar to anyone who has had to reduce spot frequency interference. It would be easier to build such a notch circuit into the feed line, and apply its measured loss versus frequency to the loop output, but if the loop antenna contains an RF preamplifier, this will not prevent overloading that. By coupling a resonant tank to the loop itself, the overloading signal may be reduced at the amplifier input. In this case the effect of the notch filter could either be modelled as you suggest, or accommodated during calibration of the antenna. I suspect the latter may be simpler to do. If a notching circuit is fixed in position with respect to the loop antenna, its effect will not vary any more than the loop antenna's own factor varies, and could be usable for SOME measurements on the particular site where single frequency interference is a problem. Realistically, why use an antenna vulnerable to overload on a site where strong signals exist? This looks like a case where a passive loop antenna is a better choice than one with a built-in preamplifier. Regards, Cortland ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
