Hi Ken, A lot of that work is I belive being done at NIST right here in Boulder under the direction of Dr R. Johnk. Some presentations he has made can be downloaded from our website at http://www.ieee.org/rmcemc under "Archives". Search for Johnk.
Best Regards Charles Grasso Senior Compliance Engineer Echostar Communications Corp. Tel: 303-706-5467 Fax: 303-799-6222 Cell: 303-204-2974 Email: charles.gra...@echostar.com; Email Alternate: chasgra...@ieee.org From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Sunday, July 27, 2003 3:35 PM To: Cortland Richmond; ieee pstc list Subject: Re: pulse modulation in reverb chambers That mostly makes sense, except I'm not sure about this part: "I'd expect a pulse to excite many modes within a chamber as long as either its length or its transition times are shorter than the time it takes a wave to travel across the chamber and back. That'll smear the pulse." My thinking is just the opposite. The duration of the pulse should be long relative to the time it takes to travel from transmit to receive antennas. Then there is no smearing. I also recall work using network analyzers and time windowing to electronically create an anechoic chamber out of an unlined screen room. > From: Cortland Richmond <72146....@compuserve.com> > Date: Sun, 27 Jul 2003 16:44:20 -0400 > To: Ken Javor <ken.ja...@emccompliance.com>, ieee pstc list > <emc-p...@ieee.org> > Subject: Re: pulse modulation in reverb chambers > > Ken, > > A recent article on reverberant chambers mentions a Q of 83,000 or so. > I'd expect a pulse to excite many modes within a chamber as long as > either its length or its transition times are shorter than the time it > takes a wave to travel across the chamber and back. That'll smear the > pulse. On the other hand the FIRST pulse received shouldn't be smeared > unless the pulse is longer than the time it takes a reflected wave to > arrive at the antenna. If I recall correctly, there've been some > papers on time gating to take advantage of this. > > 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
