FCC EMC testing - Page 1
Forum section: electronics / rf-microwave

author: JoeyG
author_rank: Regular Contributor
timestamp: July 21, 2020, 12:45:06 pm
content: Apologies for the cross post, but I didn't get a reply from the other forumhttps://www.eevblog.com/forum/projects/fcc-part-15-emc-product-certification-questions/msg3142878/#msg3142878**Is this the right forum?**Thanks in advance. I am looking at testing a product that has an mcu + WiFi wireless module and I have a few questions I hope the group and answer.BackgroundThe electronic product will go through FCC certification.It has a 200MHz mcu + WiFI wireless moduleThe WiFi module already has FCC modular certification, the question is about EMC testingEMC FCC Certification Test Method QuestionWhat mode(s) should the WiFi module be in during EMC testing?-WiFi module off-WiFi module on, but is idle mode , not connected to an access point-WiFi module on an connected to an access point-OtherRegsJoey

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 21, 2020, 01:45:44 pm
content: That's a good question to ask the test house!Tim

author: CaptDon
author_rank: Super Contributor
timestamp: July 21, 2020, 01:54:58 pm
content: Because it will be in an anechoic chamber during theRadiated Emissions testing it won't be able to link toanything. They may want to do a test with the WiFioff to show that nothing else in your product wouldinterfere with the WiFi device being able to receivea signal. Will you also do the susceptibility testingto see if external R.F. fields will disrupt your device?We currently pay over $2000 for a full 8 hour dayof testing at our local lab.

author: Neilm
author_rank: Super Contributor
timestamp: July 21, 2020, 06:50:19 pm
content: The module should be in the same configuration as it would be in normal use.The reason is that just because your module is compliant, this DOES NOT mean that your product will be compliant. I have seen (and experianced) issues where a unit operating with the RF transmitter off passed with no problem (more that 8 dB below the limit) but with the transmitter on then harmonics were picked up on internal cables and re-raditated. This turned the mains supply cable into a surprisingly good antenna.Also, with the RF transmitter will almost certainly mean the test spectrum will be larger. For instance I know on the standards we use at work a 200 MHz clock will only require testing up to 1 GHz, but with an RF transmitter the testing will have to go up to 5 times the maximum frequency.My normal disclamer - As far as you know I am just some oik on a forum who knows nothing. Talk to your test house as they will know more about the details of the standard you are trying to meet.

author: JoeyG
author_rank: Regular Contributor
timestamp: July 22, 2020, 06:13:27 am
content: In the UK and Europe - there isnoWireless RF "modular" certification (not EMC).There isWireless RF modular certification for FCC (not EMC)See herehttps://apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?switch=P&id=44637Even in the UK and Europe the question still need to be clarified as two RF standards are applied for testing EMC and 2.4GHz wireless.The question remain how is the WiFi treated during FCC EMC testing