Wireless power transfer (WPT) devices operating at frequencies above 9 kHz are intentional radiators and are subject to either Part 15 and/or Part 18 of the FCC rules. The specific applicable rule part depends on how the device operates, and if there is communication between the charger and device being charged.
Devices specifically intended for use for wireless power transfer, or inductive charging, require FCC guidance for frequency exposure review. This includes Part 18 devices. It may be necessary for the responsible party (manufacturer) to seek guidance from the FCC on specific WPT devices by submitting a KDB inquiry, http://www.fcc.gov/labhelp.
The inquiry should include the following:
- complete product description, including coil diameters , number of turns and current;
- FCC Rule Part(s) the device will operate under and the basis for selecting the Rule Part(s);
- planned equipment authorization procedure (i.e., SDoC or certification);
- drawings, illustrations;
- frequency of operation;
- radiated power;
- operating configurations; and
- conditions for human exposure.
Intentional radiators transmitting information must be certified under the appropriate Part 15 Rules and will generally require an equipment certification. A WPT device may operate in two different modes: charging and communications. It is possible for the device to be approved under Part 18 for the charging mode and Part 15 for the communications mode, if it can be shown that (1) the device complies with the relevant rule parts; and (2) the functions are independent. Part 18 consumer devices can be authorized using either certification or SDoC, once the appropriate RF exposure evaluation has been completed.
Finally, it is possible that the power charging function could be approved under Part 15 rather than Part 18 if the device meets all of the requirements of the appropriate Part 15 rule.
Attachment 680106 D01 RF Exposure Wireless Charging Apps v03r01 provides general guidance on the information necessary to determine RF exposure evaluation and compliance requirements when submitting a wireless charging application inquiry.