spectrum analyzer/receiver for pre-compiance and diagnostic testi ng
Hi! Group: We want to buy a spectrum analyzer or EMI receiver for our pre-compliance/diagnostic EMI testing (both conducted and radiated). We want something cheap and cover a wide frequency range. Do you guys have any specific recommendations ? Recently I found one of HP's new product called EMI analyzer E 7400 series. Anyone have experience with this instrument ? Any comments ? Thanks in advance. Best Regards Qu Pingyu - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Horn antennas, pre-amplifier, and return loss measurement
Bai: Are you sure that SA + waveguide coupler is a cheaper solution for your return loss measurement ? For a wide band of microwave frequency, you may need a lot of different waveguide couplers, which may cost thousand bucks themselves. Another problem is accuracy. It's not easy to calibrate your setup to make sure that what you measured is return loss from your EUT rather than something else such as mismatch at the connection between your waveguide and SA. Just my 2 cents. Regards Qu Pingyu -Original Message- From: Leslie Bai [SMTP:leslie_...@yahoo.com] Sent: Friday, 13 August 1999 1:15 To: 'emc-p...@majordomo.ieee.org' Subject: Horn antennas, pre-amplifier, and return loss measurement Hi, Folks, Is there anyone can direct me to some sources of horn antennas preamplifiers. What I need are sets of horn antenna for spurious emissions testing to meet FCC Part 101. 1 to 18GHz, 18 to 26.5GHz, 26.5 to 40GHz, or 18 to 40GHz instead, 40 to 60GHz, 50 to 75GHz, or 40 to 75GHz instead, 75 to 110GHz, 110 to 170GHz, or 75 to 170GHz instead. Due to the significant space loss over 110GHz, I guess I also need a set of preamplifier from 110 to 170GHz. I am also studying on return loss measurement methodologies to meet ETSI requirement for radios RF port. Since NAMAS calibration of network analyzer may cost thousands bucks, I am wondering if I could achieve a good result (in terms of accuracy and uncertainty) using spectrum analyser and waveguide coupler. If anyone by any chance has an ready error model of the test setup using spectrum analyzer and waveguide coupler, I appreciate you could share with me to short my research path. Thanks in advance. Leslie Bai Senior Compliance Engineer Compliance Quality Manager Digital Microwave Corporation 170 Rose Orchard Way San Jose, CA 95134 Tel: (408)-944-1754 _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
FW: cost effective EMC facility
Hi, guys: Thanks you very much for your reply to my question regarding cost effective EMC facility. Your suggestions/opinions are very helpful for me to find out the right thing for our organization. It seems that compact anechoic chamber are favoured by many of you. I will try to look for more information about the chamber, in particular the cost, and see whether my manager are willing to invest the money. Best Regards Qu Pingyu - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
cost effective EMC facility
Hello, everyone: I posted an question several weeks ago asking about GTEM. Thanks those who share with me your experience. I may not address my problem very clearly thus I would like to come back to you one more time. We are a R D orgnization in Singapore mainly dealing with semiconductor industry. Since there are some requirements from our industry partners in the area of EMC design, we are considering setting up some EMC measurement capabilities. At the intial stage, we will only consider equipment for radiated emission/susceptibility testing. Our objective is to evaluate the EMC performance of the product from our customers, being of PCB level or system level. Based on those results, we can help our customers to improve their product EMC design so that their product can pass the final compliance testing. The EUT could be small, such as integrated circuits on PCB, but it can also be large such as a PC. Due to our budget constraint, I think GTEM maybe a good choice. Do you guys agree ? If not, any other suggestions ? Thanks in advance. Best Regards Qu Pingyu - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: 50 ohm 75 ohm
Bai: If you have a Network Analyzer, just connect the cable to the two port of the analyzer through a BNC-SMA adpator. Measure the reflection coefficient (S11 or S22) and the 75 ohm cable should have a larger reflection. That's my expensive way of doing it.:-) Alternatively, if the two cables are made of the same material, maybe you can check the ratio of outer conductor radius vs. that of inner conductor. The one with larger ratio should have high impedance. Regards Qu Pingyu -Original Message- From: Leslie Bai [SMTP:leslie_...@yahoo.com] Sent: Wednesday, 14 July 1999 1:36 To: emc-p...@majordomo.ieee.org Subject: 50 ohm 75 ohm Dear members, Anyone there can share the experience to measure cables' impedance thus to identify whether a BNC is a 50 ohm or 75 ohm cable. Thanks, Leslie _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
GTEM cell
Hello, Everyone: I have some questions regarding the GTEM cell. Here in our Institute we are considering setting up some EMC measurement capability for precompliance testing. The EUTs we are dealing with are not very large, probably not larger than a desktop PC. Do you think that GTEM cell is a good choice ? Do many of you use GTEM as a precompliance testing facility ? Your comments are highly appreciated. Regards Qu Pingyu - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
TEMPEST
Hello, Group: Can somebody tell me what does TEMPEST stand for ? I know roughly what TEMPEST is about but I can't find out what these 7 letters represent either from books or internet. I suppose this is some kind of abbreviations, isn't it ? Regards Qu Pingyu - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
FW: Transmission Line Theory
Hello, Group, My first post was bounced back by the server. Don't know what's wrong. Here I send it again. I appologize if you already recieved the first post. Regards Qu Pingyu -Original Message- From: Qu Pingyu Sent: Thursday, 13 May 1999 9:31 To: emc-p...@ieee.org Subject: RE: Transmission Line Theory Hello: Regarding your question, you can refer to the paper by C.R. Paul on IEEE Trans. EMC, Vol. 31, No.2, May 1989. As I understand, the radiation emission in this case is due to the differential mode (DM) current and common mode (CM) current. According to Paul, the contribution from common mode current is far severe than that from the DM current. The reason is CM current on signal trace and return path tends to enhance each other, while DM current tend to cancel each other. In his paper, he gave the formular to calculate the radiated electric field due to both CM and DM current. As to the termination at the end of the traces, I don't have a thorough study myself. But I guess that at least one end of the traces should be terminated with impedance which matches the characteristic impedance of the trace. If both end are not matched, the transmission line will act as an resonator and the radiation will be very strong for those frequencies that satisfy the following fomular: L = n x lamda/4, Where n is an integer and lamda is the wavelength of radiated field. Hope this helps. Regards Qu Pingyu -Original Message- From: Allen Tudor [SMTP:allen_tu...@pairgain.com] Sent: Thursday, 13 May 1999 5:31 To: emc-p...@ieee.org Subject: Transmission Line Theory Greetings group, I am trying to draw a parallel between transmission line theory and radiated emissions. From what I understand, a transmission line can be terminated at the source or the load with an impedance that equals the characteristic impedance of the transmission line itself. With this in mind, consider this scenario. A printed circuit card drives a clock signal down a trace on a backplane. The length of the backplane trace is long enough to be considered a transmission line. The driver on the printed circuit card is located within ½ inch of the edge connector (mating with the backplane) and is terminated with an impedance equal to the characteristic impedance of the backplane trace. However, the backplane trace is open ended (there is nothing connected to the end of the trace). Transmission line theory says the signal integrity will be maintained in this case. Now for the questions: (1) How much, if any, of the energy will be radiated into free space when it gets to the end of the open transmission line? To me, this looks like a monopole antenna. I don't have a very good understanding of antenna theory, so this could very well be an invalid assumption. (2) If radiation does take place as stated above in question (1), which is better for reducing the radiation, termination at the source or termination at the load of the transmission line, or does it matter? (3) If the characteristic impedance of the trace on the printed circuit card differs from the characteristic impedance of the trace on the backplane, how is this handled? Is a termination needed at each end in this case? I look forward to your responses. Thanks. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Transmission Line Theory
Hello: Regarding your question, you can refer to the paper by C.R. Paul on IEEE Trans. EMC, Vol. 31, No.2, May 1989. As I understand, the radiation emission in this case is due to the differential mode (DM) current and common mode (CM) current. According to Paul, the contribution from common mode current is far severe than that from the DM current. The reason is CM current on signal trace and return path tends to enhance each other, while DM current tend to cancel each other. In his paper, he gave the formular to calculate the radiated electric field due to both CM and DM current. As to the termination at the end of the traces, I don't have a thorough study myself. But I guess that at least one end of the traces should be terminated with impedance which matches the characteristic impedance of the trace. If both end are not matched, the transmission line will act as an resonator and the radiation will be very strong for those frequencies that satisfy the following fomular: L=n x lamda/4, Where n is an integer and lamda is the wavelength of radiated field. Hope this helps. Regards Qu Pingyu -Original Message- From: Allen Tudor [SMTP:allen_tu...@pairgain.com] Sent: Thursday, 13 May 1999 5:31 To: emc-p...@ieee.org Subject: Transmission Line Theory Greetings group, I am trying to draw a parallel between transmission line theory and radiated emissions. From what I understand, a transmission line can be terminated at the source or the load with an impedance that equals the characteristic impedance of the transmission line itself. With this in mind, consider this scenario. A printed circuit card drives a clock signal down a trace on a backplane. The length of the backplane trace is long enough to be considered a transmission line. The driver on the printed circuit card is located within ½ inch of the edge connector (mating with the backplane) and is terminated with an impedance equal to the characteristic impedance of the backplane trace. However, the backplane trace is open ended (there is nothing connected to the end of the trace). Transmission line theory says the signal integrity will be maintained in this case. Now for the questions: (1) How much, if any, of the energy will be radiated into free space when it gets to the end of the open transmission line? To me, this looks like a monopole antenna. I don't have a very good understanding of antenna theory, so this could very well be an invalid assumption. (2) If radiation does take place as stated above in question (1), which is better for reducing the radiation, termination at the source or termination at the load of the transmission line, or does it matter? (3) If the characteristic impedance of the trace on the printed circuit card differs from the characteristic impedance of the trace on the backplane, how is this handled? Is a termination needed at each end in this case? I look forward to your responses. Thanks. Allen Tudor, Compliance Engineer PairGain Technologies tel: (919)875-3382 2431-153 Spring Forest Rd. fax: (919)876-1817 Raleigh, NC 27615 email: allen_tu...@pairgain.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EMC Resources on the web
Hello: I just found the following site and I think it's very good: http://gallery.uunet.be/rlogghe/emc.htm Regards Qu Pingyu -Original Message- From: randall.flind...@emulex.com [SMTP:randall.flind...@emulex.com] Sent: Wednesday, May 05, 1999 5:00 PM To: 'emc-pstc' Subject:EMC Resources on the web Hello! Greetings from Orange County! I am interested in compiling a list of valuable EMC related resources available on the web. If you kind guys and gals out there could address them to me, I will compile the results and post them for the group all at once. Thanks! -- Sincerely, Randall T. Flinders EMC Engineer Emulex Network Systems V: (714) 513-8012 F: (714) 513-8265 randall.flind...@emulex.com __ __ __\ /__ __/ \__ E M U L E X Chairman Orange County Chapter IEEE EMC Society r.flind...@ieee.org - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EMC Books
Barry: I don't think the 1996 version of Montrose's book is good. Though there are many useful design rules listed, the reason behind is not explained very clearly. I also attended a course on PCB EMC design conducted by Mr. Montrose himself and I have to say I was quite disappointed. I second your recommendation for the second and third book listed on the wegb page (I havn't read the first one I would like to), plus Paul's Introduction to EMC. Regards Qu Pingyu -Original Message- From: b...@namg.us.anritsu.com [SMTP:b...@namg.us.anritsu.com] Sent: Friday, 7 May 1999 0:20 To: smtp@WILTRON7@Servers[\Jon D. Curtis\ j...@curtis-straus.com]@namg.us.anritsu.com Cc: emc-p...@ieee.org Subject: Re: EMC Books Jon, I just visited your book store. Very pertinent comments on each book although brief. The first three books should be listed must read for EMC engineers. Suggestion for the book of Printed Circuit Board Design Techniques for EMC Compliance, Mark I. Montrose, 1996: The newest edition seems to be 1998? The new edition added much more materials on Signal Integrity. Barry - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: where to buy EMC standards
Hello, Everyone: First of all, I would like to thank all of you who provide me with the information about purchase of standard. I have another question raised after I read the reply from Mike: Can I say that CISPR 22 is the same as EN55022 and IEC 1000-4-1,2,3,4 the same as EN61000-4-1,2,3,4 ? If not, what is the difference ? Regards Qu Pingyu -Original Message- From: mmert...@modicon.com [SMTP:mmert...@modicon.com] Sent: Friday, 30 April 1999 22:30 To: Qu Pingyu Subject: Re: where to buy EMC standards I am sure you will receive many identical replies to your questions, but here is mine... My most reliable source for documents is Global Engineering Documentshttp://global.ihs.com/ Global is more expensive than average, but delivery is good and they accept credit cards. There are many other sources for EMC standards, but I have found that they do not always have what I want, they do not always deliver on schedule, and many will not accept credit cards. Why do you want CISPR 22 and IEC 1000 - X? These are reference documents, and are not harmonized. The harmonized (also called normative) form of CISPR 22 is EN55022. The harmonized form of IEC 1000-X is EN61000-4-1, -2, -3, etc. FCC rules can be downloaded from many places. I use http://www.fcc.gov/oet/info/rules/ as a starting point. ANSI C63.1 can be obtained from Global. I have tried to buy documents directly from ANSI, but in 18 years I have NEVER been able to get through to them by phone, FAX, or email. They are apparently in the business of being impossible to do business with. Good luck! Mike Mertinooke - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
where to buy EMC standards
Hello, everyone: We would like to buy the following EMC standards (US and Europe): 1. CISPR 22 2. IEC - 1000 - 1,2,3,4 3. FCC CFR 47, Vol.1 4. ANSI C63.4 I suppose that these are the most frequently-used standards in EMC testing. (Do I miss anything ?). I would appreciate if anybody could tell me where I can buy these standards. Regards Qu Pingyu - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
