I upgraded a chamber at hp and looked at: 1) How to pass the 16 point call up to 3 GHz 2) How to upgrade /change add absorbers 3) Which commercial antenna works best from 26 Mhz - 3 GHz 4) How much power is needed. 5) How well does the signal repeat. 6) Field probes 7) etc.
The lab is the Hewlett-Packard Roseville Hardware Test Lab. On (2): It turned out that adding absorbers to the floor always spoiled the low frequency (about 80-150MHz) if it improved the high frequency. No matter which absorber type or arrangement on the ferrite-floor tried. But one topology worked very well: Having 5 inch absorbers placed 60 cm above the ground (on a Styrofoam support). Two of those absorbers were placed between the antenna and the turntable. In this arrangement the 16 point cal was passed from 26 MHz to 2.9 GHz (I did not measure any higher). The "shadow" of the absorber did not reduce the field strength at lower frequencies below 0.8 m height a lot (although there is no regulation on the field strength below 0.8 m). I looked at different log-per antennas (needed power, effect on 16point cal, robustness, weight, handling, SWR, etc.). None of them was a clear winner. Gain wise (judging by needed [power to achieve a certain field strength in this specific chamber), the EMC-Automation antenna was a little a head, but it is also larger and quite heavy. Cable loss is an important factor. Using 25 Watt and having about 3m cable will allow 10 V/m, but there may already be some distortion in the modulation. I think 25 Watts is the minimum for10 V/m from 1 GHz to 3 GHz. Signal reproduction is not that bad, but mechanical positions of absorbers, antenna etc. needs to be controlled very well. All the field probes I tested had some problems. Some did not fulfill their isotropicity specifications, some did not fulfill the frequency response specifications some did not allow the promised number of measurements a second. But for every probe there was a combination of position relative to the field and sampling rate at which it provided good data. If you need any further information, contact me. If you want to use the chamber for immunity testing contact Ken Hall ken_h...@hp.com David Pommerenke University Missouri-Rolla, 1870 Minor Circle, 118 EECH Rolla, MO 65409-0040 ph: 573 341 4531 home: 573 341 5835 fax: 573 341 4532 email: pommere...@ece.umr.edu -----Original Message----- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Tuesday, August 07, 2001 1:41 PM To: emc-p...@majordomo.ieee.org Subject: RE: ETSI EMC Standard An ETSI representative told me that he thought that most all EU labs have upgraded their chambers and equipment and are now ready to test. That same person asked if the US labs were also ready? Let's hear from both sides of the Atlantic. Are you prepared? Richard Woods ---------- From: umbdenst...@sensormatic.com [SMTP:umbdenst...@sensormatic.com] Sent: Tuesday, August 07, 2001 1:20 PM To: emc-p...@majordomo.ieee.org Subject: RE: ETSI EMC Standard Regarding the change in the standard, has anyone started to look into an upgrade to their compact chambers for stre-e-e-etching the frequency to 2 GHz? If so, what upgrades did you find most cost effective for * signal generator * amplifier * antenna * sensor * e-field probe * chamber lining modifications Perhaps we can develop a database of options and trade-offs before we need to spend the big bucks. Don Umbdenstock Sensormatic ? > ---------- > From: wo...@sensormatic.com[SMTP:wo...@sensormatic.com] > Reply To: wo...@sensormatic.com > Sent: Tuesday, August 07, 2001 10:15 AM > To: emc-p...@majordomo.ieee.org > Subject: ETSI EMC Stadard > > > The final draft of the proposed revision of ETSI EN 301 489-1 is in the > voting stage. This standard sets the emissions and immunity requirements > for > most all transmitters. A major change has been made to the radiated > immunity > requirements by adding the frequencies between 1400 MHz and 2000 MHz. I > was > told that this change is being driven by CISPR and may be based upon a > CISPR > standard. Does anyone have any information in this regard? > > Richard Woods > > ------------------------------------------- > 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: > http://www.rcic.com/ click on "Virtual Conference Hall," > ------------------------------------------- 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: http://www.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: http://www.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: http://www.rcic.com/ click on "Virtual Conference Hall,"
