I can say, from personal experience, that high speed I2S bus communications with a modularly approve intentional radiator makes a significant change in the unintentional emissions. It may be/has been necessary to use a band notch filter at the fundamental intentional frequency to keep from overloading the measurement receiver during the investigation though.
In a perfect world, it might be possible to communicate with the intentional radiator at full speed, but with vastly reduced transmit power, which would seem to serve the same purpose. Just another thought, Brent -----Original Message----- From: T.Sato [mailto:[email protected]] Sent: Friday, July 21, 2017 2:10 PM To: [email protected] Subject: [PSES] application of CISPR 32 to EUTs with integrated radio transmitters Hello members, I want to hear of your opinion - while emission measurement for CISPR 32, integrated radio transmitters must transmitting? Although the standard is not clear whether radio transmitter can be set off in emission measurement, I believed we can set radio transmitter off, as: - CISPR 32 said "The radiated emission requirements in this standard are not intended to be applicable to the intentional transmissions from a radio transmitter as defined by the ITU, nor to any spurious emissions related to these intentional transmissions." - If non-transmitter function of the equipment (such as CPU clock and harmonics) generates emissions in the frequency band of the intentional transmission of the transmitter (such as 2.4 to 2.5 GHz), I think we should apply the emission limits as the emissions are not related to the intentional transmissions. However, it is difficult to measure such emissions in presence of the intentional transmission. - The standard says "Compliance can be shown by measuring the EUT's emissions when operating its functions simultaneously, individually in turn, or any combination thereof." So, even if emissions from the transmitter function must also be considered in the standard, it should permissible to test non-transmitter function of the equipment while transmitter is set off. - Then, if the transmitter function of the equipment is tested while all the other functions are set off, all the emissions measured are those caused by the transmitter. However, I heard of strong opinions that the emission measurement must be run while the integrated radio transmitter is transmitting, and all the emissions in the frequency bands of intended transmissions and those harmonics should be simply ignored. What do you think about this? Regards, Tom -- Tomonori Sato <[email protected]> URL: http://t-sato.in.coocan.jp - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
