FCC part 15 sets the standards for intentional, unintentional, or incidental radiation sources that can be operated without an individual license.
Digital devices used in vehicles in roadway, airway, or waterway transportation fall under FCC part 15 exemptions.
Non-licensed low-power transmitters that comply with FCC part 15 regulations are generally called FCC part 15 transmitters.
Digital devices used in vehicles in roadway, airway, and waterway transportation are exempt from FCC part 15 regulations
Products that are EMC compliant are immune to electromagnetic interference and do not disturb the operation of nearby devices. Electromagnetic compliance is a requirement for all electrical and electronic devices available on the market; manufacturers must follow EMC standards to ensure their products are reliable in electromagnetic environments.
When we discuss EMC compliance, testing, and standards, we often mention several common standards--such as IEC 61000, CISPR 25, FCC part 15, etc. These EMC standards are regulations set by national or international organizations to limit the interference from or to devices within allowable levels. EMC testing is conducted to make sure the product under test produces interference within the acceptable limits stated in these standards.
Among the various EMC standards, FCC part 15 is a common standard that sets the limits on intentional, unintentional, or incidental radiation sources that can be operated without an individual license. In this article, we will discuss FCC part 15 standards and exemptions as well as FCC part 15 transmitters.
FCC Part 15 Standards
The Federal Communications Commission (FCC) devises regulations for digital and electronic devices under the Code of Federal Regulations, Title 47, Part 15, 47 CFR 15, which is commonly called FCC Part 15 regulations. The regulation criteria under FCC part 15 ranges from spurious emissions to unlicensed low-power broadcasting.
FCC part 15 sets the limits on electromagnetic interference on devices such as wristwatches, computers, telephones, musical instruments, low-power transmitters, etc. Devices that do not comply with the FCC part 15 standards will cause issues for engineers, suppliers, distributors, and customers. In such cases, the distribution of non-compliant products stops, and fines are imposed on the manufacturer.
Classification of Devices Under FCC Part 15
FCC part 15 classifies devices that are intentional, unintentional, or incidental radiating sources.
- Intentional radiators are devices that produce and emit electromagnetic energy intentionally through radiation or induction. These devices are generally called radio transmitters. Examples include garage-door openers and cordless telephones.
- Unintentional radiators are devices that intentionally generate electromagnetic energy for use within a device and send it through conduction instead of radiation or induction. Examples include superheterodyne receivers and computer systems.
- Incidental radiators are devices that are not designed to generate, use, or emit radio-frequency energy, but might produce or emit radio-frequency energy while in normal operation, which can cause interference. Examples include dimmer switches and elevator motors.
FCC Part 15 Exemptions
There are several devices that are exempted from FCC part 15 regulations. They fall under FCC part 15, section 103. Some of these exempted devices are:
- Digital devices in vehicles used in roadway, airway, or waterway transportation.
- Digital devices used in industrial plants and public utilities as electronic control systems.
- Digital devices used as test equipment in commercial, industrial, and medical systems.
- Digital devices in home appliances that are designed for converting electrical energy into heat or motion.
- Special medical digital devices in health care facilities that can only be used under the supervision of a licensed health care practitioner.
- Digital devices with a power rating of 6 nW or less.
- Non-digital circuitry, such as a joystick or mouse, used along with digital devices.
- Digital devices that are not using frequencies above 1.705 MHz and do not operate while being charged or connected to the AC mains through a power cord.
- Equipment containing multiple devices.
FCC Part 15 Transmitters
Non-licensed low-power transmitters that comply with FCC part 15 regulations are generally called FCC part 15 transmitters. FCC part 15 transmitters are low-power devices that are within 1 mW. Such transmitters can be operated without a license from the FCC. Even though a license is not required for such transmitter operation, an FCC authorization is required before these transmitters can be legally marketed. FCC authorization ensures that FCC part 15 transmitters comply with FCC technical standards and do not cause interference to authorized radio communications.
Some FCC part 15 transmitters include:
- 802.11 wireless Local Area Networks utilizing 2.4 GHz, 5GHz Eg. WiFi.
- 802.15 Personal Area Networks utilizing 2.4 GHz E.g. Bluetooth, ZigBee.
- Cordless phones utilizing 900 MHz.
- Low power transmitters that air a repeating loop of highway construction, traffic, promotional, or advertising information.
- Wireless headsets and microphones that broadcast to a receiver, which amplifies the audio.
- Walkie talkies intended for baby monitors, children's toys, and some cordless phones that operate on frequencies in the 49 MHz band.
There have not been many changes to RF emissions limits since their establishment in the 1990s. The FCC part 15 transmitter list remains more or less the same, with the FCC recommending that manufacturers use proper design and manufacturing practices to minimize interference risks. However, there are some new inclusions made in FCC part 15 exemptions, such as high power antennas with certain specific absorption rates (SAR) and transmitters with specific maximum permissible exposure (MPE) values.