EMCS Standards Activity: Old San Juan Hosts IEC/CISPR Standards WG Meeting

To continue our coverage of international EMC standardization, we now report on an IEC Special International Committee on Radio Interference (CISPR) working group (WG) meeting in San Juan, Puerto Rico the last week in June. The particular working group that met is that associated with CISPR Subcommittee I, which deals with EMC of information technology equipment (ITE), multimedia, and receivers. Our gracious host was John Lichtig of Lichtig EMC Consulting who chaired his WG3 meeting dealing with the latest standardization maintenance of the well-known CISPR 22 standard covering emissions for ITE products. John was born and raised in Puerto Rico and helped to “translate” the local color as he dealt with the hotel staff and of course dining at historical restaurants dating back to the mid 1800’s. But enough of the tourist pitch and on to what happened at this WG meeting and the following task group meeting of WG2, which deals with emission standardization of multimedia equipment. This is scheduled to be published in the next couple of years as CISPR 32.

The sign at the entrance to observatory with Don Heirman (left) of the USA and Ton Almering of The Netherlands, both members of CISPR SC I/WG3.

Overall view of observatory telescope showing the dish reflector and suspended receiver location.

The commemorative plaque placed on the observation visitor platform shows the IEEE and ASME identifying the observatory as a landmark installation.

WG 3 had a full agenda covering the following topics largely covered by task forces assigned by the WG. The decisions and discussions follow each topic:
1. A report of the task force on impedance stabilization networks for the telecommunication ports was presented that indicated that a final draft international standard (FDIS) was being written which will delete the 30 dB Longitudinal Conversion Loss (LCL) ISN which is now in CISPR 22. There was no longer a need for this ISN.
2. There is work proceeding by the task force on non-invasive telecommunication port measurements. The thrust of this work is to measure common mode current on cables attached to these ports communicating with other ITE equipment without having to cut the cable to insert a measuring device such as an impedance stabilization network (ISN). The measurement is performed using a current probe as well as a capacitive voltage probe.
3. The task force on test setups reported that their work was completed with the publication of CISPR 22, Fifth Edition. However, it was suggested that this task force remain in existence and shift its activity to assisting and commenting on CISPR 32, which is scheduled to replace CISPR 22 at some point.
4. The task force activity for developing a measurement method and limits for power line communication systems is now a part of the CISPR I subcommittee activity and no longer in WG 3. Note: This CISPR I task force met the day before the WG 3 meeting at the same venue and had over 20 attendees sorting through the work necessary to achieve an amendment to CISPR 22 to measure such systems and to provide acceptable limit levels.
5. The work on measurement instrument uncertainty continues with the WG requesting that consideration be made to account for such uncertainty in stating product pass/fail decisions, which are demonstrated in standard CISPR 16-4-2. At present, only reporting the uncertainty is required and not the need to take it into account in unequivocally stating product passing or failing a limit. The author was asked to draft a document for comment that will give the national committees an opportunity to comment on adding the full impact of measurement instrumentation uncertainty to state pass/fail. If accepted, this would fully satisfy Publication 16-4-2.
6. There is considerable work by a task force on determining what is the appropriate traffic loading that should be used when making emission measurements on products sending/receiving such traffic on their communication ports. It is of significant interest as it was described that the difference in emissions may be as much as 20 dB between systems with 10 percent (or idle) traffic to those with 100 percent traffic.
7. Finally, it was reported and in a sense celebrated, that the long road to derive limits above 1 GHz has met a successful end, i.e. limits between 1 and 6 GHz have passed national committee vote and will go into affect as an amendment to CISPR 22 probably before the end of the year.

Dr. Murray Lewis (far right) chats with (from left) Steve Martin of the US FCC, Ghery Pettit of Intel and WG 3 member, and John Lichtig, Chair of CISPR SC I WG 3 and host for the WG 3 meeting, prior to start of the observatory tour.

CISPR Chairman Peter Kerry walks “gingerly” on a catwalk to the center of the suspended receiver of the telescope.

CISPR WG 3 and WG 2 members inspect the suspended receiver area, which shows the complicated structure to help keep the receiver in focus with the reflector 145 meters below.

WG 3 members view the observatory reflector.

The WG 2 task group on developing CISPR 32 met the next day and then two days later. In the intermediate day, John arranged a very special trip to the Arecibo Observatory and its National Astronomy and Ionosphere Center outside San Juan. The observatory is managed by Cornell University in the USA and is funded by the US National Science Foundation. The observatory has the largest curved focusing antenna (using the largest single-dish telescope) on the planet measuring about 300 meters in diameter, 54 meters deep with a focus suspended approximately 145 meters above the reflector dish, which covers 20 acres. It is also an interesting fact that the telescope provided the backdrop for two Hollywood movies: “Golden Eye”, a James Bond flick with Sean Connery, and “Contact” with Jodi Foster.
At the meeting venue next to the visitor center, Dr. Murray Lewis (Senior Research Associate) and Dr. Jon Hagen (Assistant Director for Technical Services) met with the CISPR attendees. Dr. Lewis in fact arranged the visit for the over two dozen CISPR attendees. After a brief introduction and review of the purpose of the observatory, both gentlemen and representatives of the over 140 employees at the site split the groups up and led them on a tour of different parts of the campus and also gave them a tour of the facility.

The spherical reflector covers over 20 acres!

The highlight of the tours was allowing the attendees (who were not afraid of heights) to walk on the catwalk to the suspended focus of the system where the sensitive receivers are located. These receivers are able to listen to signals anywhere from within our own galaxy and beyond to distant stars. The view was breath taking as well as challenging to access portions of the observatory as can be seen in the photos accompanying this article. Note the president of CISPR, Peter Kerry, is shown above struggling along the catwalk high above the reflector dish. Another photo shows the intricacies of the suspended receiver structure. Even the trip to the bottom of the reflector was memorable in noting that the reflector was a portion of a perfect sphere and was constructed to be within +/- 2 mm if a radius from the center of the sphere traced the entire surface of the reflector! Other tours visited the electronics laboratory where the controls that “aim” the telescope are housed. During that portion of the tour, there was also an opportunity to view the amplifiers that are used for “active” tracking of objects using techniques similar to radar. The operating frequencies are in the 450 and 2400 MHz bands.
After the tours, the attendees reassembled and met again with Dr. Lewis. Peter Kerry, CISPR President, presented a review of what CISPR does and its responsibilities. Martin Wright followed this, Chair of CISPR SC I, indicating the many projects that his subcommittee was leading including the recent controversial standardization on powerline communication. Following Martin’s presentation, Don Heirman, Chair of CISPR SC A, spent time comparing the work of his committee’s basic measurement and test instrumentation work to that he heard during the tour of the observatory. For example, the observatory design provided antenna gains of up to 70 dB around 450 MHz, which is close to 60 dB more than antennas used in making radiated emission measurements at the same frequency. In any case, the tour and discussions were quite memorable and CISPR thanks the management and staff of Arecibo who spent so much time with the attendees. For details on the observatory, log into www.naic.edu.

Dr. Jon Hagen (right) holds a demonstrator 450 MHz amplifier component during the tour as Ron Storrs, Chairman of CISPR SC I WG2, (left) and Fujio Amemiya, WG 3 member from Japan (center) watch intently.

CISPR I WG 3 members view the 450 MHz amplifier used in the active probing of the solar system work of the observatory. Dr. Hagen (far right) is explaining its use.

Back to the WG2 task group activity! Draft inputs were discussed and amended and additional work was identified. The document starting point was contained in CISPR/I/146/DC. Here the national committees saw for the first time the intent of the combination of CISPR 22 and CISPR 13 (receivers) into a new all inclusive multimedia form. There were over 125 comments on the DC (document for comment) from the National Committees. The task group then started addressing and hopefully resolving the comments as well as reviewing proposed annexes including:
1. Annex A that shows the test setups for EUTs and those devices which connect to and communicate with the EUT during compliance testing. This annex is largely taken from the present CISPR 22, Fifth Edition, except for including full frames such as those for telecommunications switching offices as the work is focusing on products which are sold everywhere, not commercial or professional installations.
2. A companion annex that showed how to configure and exercise the EUT. This included a matrix showing how to exercise ports of the EUT including a new “H” pattern complete with color bars according to ITU-R recommendation BT 471-1.
3. Annex B that provides product family test requirements and clarifications including measurement automation techniques. The proposed annex makes significant use of relevant parts of CISPR 16 test procedures which are contained in the CISPR 16-2-X series of standards.
4. Annex C then proposed specific test setups for emission testing for a wide range of product types. The task group decided to also include a more generic test setup so that new product types would not require yet another set of example test setup figures. But for the moment, the test setups included those for: