Hello,
I'm re-sending this because I received comments that nobody had answered it (and I guess people were expecting me to answer it :) ) Thanks, Michael. From: Michael Derby [mailto:micha...@acbcert.com] Sent: 08 September 2017 09:18 To: 'Grasso, Charles' <charles.gra...@dish.com>; 'EMC-PSTC@LISTSERV.IEEE.ORG' <EMC-PSTC@LISTSERV.IEEE.ORG> Subject: RE: [PSES] Composite Systems and Intentional Radiators Hi Charles, I added some comments in red text to your mail below... Michael. From: Grasso, Charles [mailto:charles.gra...@dish.com] Sent: 07 September 2017 18:17 To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] Composite Systems and Intentional Radiators Hello, I am soliciting help in the interpretation of FCC rules as to what makes an intentional radiator and the application of standards as a result. The scenario: A product is designed and tested as an unintentional radiator and 15.109/15.107 and/or ANSI C63.4 etc test levels and methods are performed. A WiFi dual band radio is now added (not as a module) by redesign and the final product is ready for authorization. My thought process is as follows - please tell me if I have erred: 1. Test the Unintentional Portion of the new product to 15.109/15.107 etc.radio is in rcv mode. Yes, correct. 2. Test the WiFI radio portion of the product to 15.209/ANSI C63.10 and You mentioned in your text above that the WiFi is "not as a module", and therefore I do not know if the WiFi module has had any testing yet, or not. The product now needs certification (because you say the module is not certified), so you will be applying to a TCB, based on the final product (I assume that is your plan, from your message above). If the WiFi module has been tested (to 15.247 and 15.407), then you may be able to ask the module manufacturer for the test results, and, if they remain applicable to your installation of the module, you could include the conducted antenna port measurements from the module, in your application for certification of the final product. If the WiFi module has not been tested (to 15.247 and 15.407), then you will need to test those items, either at the host level or the module level. In all cases, the radiated intentional (transmitter) emissions (15.209) will need to be fully tested at the host level, because the final product is the one being certified. 3. A product is born. Congratulations. Note though there is a very specific wording in numbers 1 and 2. Considering the composite nature of the FCC rules, I am under the impression that the limits for the unintentional portion of the radio apply ONLY to the non-radio portions of the spec and the limits for the intentional portion apply ONLY to the radio. Am I correct? You are correct - mostly. You can, if you wish, stop your WiFi from transmitting while you are performing your 15.107 and 15.109 testing. So, you're correct there. When doing your 15.209 emissions, you are looking for the emissions from the transmitter, such as harmonics, intermodulation products, band edges, etc. So, you are not specifically looking at your product's other emissions. But, considering the similarity between the 15.209 limits and the 15.109 limits, you should not see any emissions exceeding 15.209, if you have already tested 15.107. (If you are saying that the WiFi is a Class B emissions limit, and the host product is a Class A emissions limit, then read 15.31(k) and see that you can apply the 15.107 Class A limits to the emissions which are not from the transmitter). But finally, I would add this caveat... If you test 15.109 with the transmitter off and it passes, you're happy. If you test 15.209 and focus on the transmitter and it passes, you're happy. But, if during those tests, you notice that somehow a combination of module and host is actually failing one of the limits but it's possible to somehow ignore it (e.g., turning the transmitter on for the 15.209 emissions, somehow causes the unintentional radiator emissions to increase and fail the limit) (perhaps the module draws a lot of current?)... You should fix it. You should not say "that's not my problem". Thanks, Michael. Thanks Charles Grasso (w) 303-706-5467 - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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