I don¹t know what the FCC rules are on something like this others on this forum are much better informed on that topic - but if the ERP is 0 dBm (1 mW), then at three meters away the field intensity would be 58 mV/m, or 95 dBuV/m. Now this is at 13.56 MHz, where there is no FCC RE limit. But the FCC Class B three meter limit at 30 MHz is something like 40 dBuV/m (someone jump in if I got this wrong) so that means the third harmonic must be 55 dB down from the fundamental. That is certainly doable, but I wouldn¹t take it for granted without some sort of verification.
Ken Javor Phone: (256) 650-5261 From: MIKE SHERMAN <[email protected]> Reply-To: MIKE SHERMAN <[email protected]> Date: Fri, 19 Oct 2018 17:22:50 -0500 To: <[email protected]> Subject: [PSES] NFC (near field communication): FCC Approach? Esteemed fellow listers -- I'm looking at a very low power, intermittent NFC card reader/writer. Alkaline battery operated device. NFC is only energized for 10 seconds at a time on demand, and range to read/write is less than 1 cm from the surface of the device. I'm not an EE, but my simplified thought process is: "I can barely get this to couple magnetically with a card sitting on its surface. How could I possibly interfere with broadcast services or other equipment?" So, oh wise ones, from your experience what actions with respect to FCC are reasonable to do? For example, radiated emissions testing seems to me like a total waste of time and money. More technical details: maximum input power to the NFC chip is 17 mW. Chip is coupled to a flat 30mm x 40mm "NFC Ferrite Antenna (13.56 MHz)" that my EE describes as "zero gain." We're rating RF output as 0 mW (i.e., rounding off, it's a lot closer to 0 mW than to 1 mW). Looking forward once again to interesting wisdom from this group. Mike Sherman Graco Inc. - ---------------------------------------------------------------- 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) <http://www.ieee-pses.org/list.html> 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]>
