The Federal Code of Regulation (CFR) FCC Part 15 is a common testing standard for most electronic equipment. FCC Part 15 covers the regulations under which an intentional or unintentional (incidental) radiator that can be operated without an individual license. FCC Part 15 also covers the technical specifications, administrative requirements and other conditions relating to the marketing of FCC Part 15 devices. The process for FCC Part 15 compliance is dependent on the type of the equipment. Devices fall under either supplier’s declaration of conformity (SDoC) or certification.
See the FCC website for more descriptive information.
FCC Part 15 Subpart A contains specific information regarding testing and certification. Information such as scope of the rules and legal implications, definitions, prohibition against eavesdropping, labeling, etc.
Definitions of interest from FCC Part 15:
Digital Device – “An unintentional radiator (device or system) that generates and uses timing signals or pulses at a rate in excess of 9,000 pulses (cycles) per second and uses digital techniques; inclusive of telephone equipment that uses digital techniques or any device or system that generates and uses radio frequency energy for the purpose of performing data processing functions such as electronics computations, operations, transformations, recording, filing, sorting, storage, retrieval, or transfer. A radio frequency device that is specifically subject to an emanation requirement in any other FCC Rule part or an intentional radiator subject to Subpart C of this part that contains a digital device is not subject to the standards for digital devices, provided the digital device is used only the enable operation of the radio frequency device and the digital device does not control additional functions or capabilities.”
Intentional Radiator – “A device that intentionally generates and emits radio frequency energy by radiation or induction.”
Class A Digital Device – “A digital device that is marketed for use in a commercial, industrial or business environment, exclusive of a device which is marketed for use by the general public or is intended to be used in the home.”
Class B Digital Device – “A digital device that is marketed for use in a residential environment notwithstanding use in commercial, business and industrial environments. Examples of such devices included, but are not limited to, personal computers, calculators, and similar electronics devices that are marketed for use by the general public.”
FCC Part 15 Subpart B applies to unintentional radiators. The category of unintentional radiators includes a wide variety of devices that contain clocks or oscillators and logic circuitry but that do not purposely generate radio frequency emissions. Among the common unintentional radiators are phones, personal computers, peripherals, receivers, radios, TV sets, and cable TV box. While most of these devices contain wireless technologies today, all must additionally comply with the unintentional emissions requirements.
The following table from FCC Part 15.101 indicates the classification of these various devices.
| Type of Device | Equipment Authorization Required |
| TV broadcast receiver | SDoC or Certification |
| FM broadcast receiver | SDoC or Certification |
| CB receiver | SDoC or Certification |
| Superregenerative receiver | SDoC or Certification |
| Scanning receiver | Certification |
| Radar detector | Certification |
| Other receivers subject to part 15 | SDoC or Certification |
| TV interface device | SDoC or Certification |
| Cable system terminal device | SDoC or Certification |
| Stand-alone cable input selector switch | SDoC or Certification |
| Class B personal computers and peripherals | SDoC or Certification |
| CPU boards and internal power supplies used with Class B personal computers | SDoC or Certification |
| Class B personal computers assembled using authorized CPU boards or power supplies | SDoC or Certification |
| Class B external switching power supplies | SDoC or Certification |
| Other Class B digital devices & peripherals | SDoC or Certification |
| Class A digital devices, peripherals & external switching power supplies | SDoC or Certification |
| Access Broadband over Power Line (Access BPL) | Certification |
| All other devices | SDoC or Certification |
Two levels of radiated and conducted emissions limits for unintentional radiators are specified in FCC Part 15 Subpart B. The two levels are Class A digital devices (the higher or less strict limits) and Class B digital devices (the lower or more strict limits). Manufacturers are encouraged to meet the Class B digital device limits.
FCC Part 15 Subpart C applies to transmitters or “intentional radiators”. The various types of intentional radiators covered by Subpart C include cable-locating equipment, wireless telephones, remote control and alarm transmitters, field-disturbance sensors for opening doors, and spread-spectrum systems for wideband data transmission. Intentional radiators governed by FCC Part 15 Subpart C must either have a permanently attached antenna or provide a unique connector to prevent the use of unauthorized antennas. The FCC Part 15 Subpart C rules for operation of radio transmitters detail the fundamental field strength, RF power, power spectral density, frequency accuracy, and permitted harmonic and spurious emissions.
FCC Part 15 Subpart D outlines the regulations for unlicensed personal communication service (UPCS) devices operating in the 1910 – 1930 MHz frequencies bands.
FCC Part 15 Subpart E sets out the regulations for unlicensed National Information Infrastructure (U-NII) devices operating in the following bands:
- UNII 1 – 5150 – 5250 MHz
- UNII 2a – 5250 – 5350 MHz
- UNII 2c – 5470 – 5725 MHz
- UNII 3 – 5725 – 5850 MHz
- UNII 5 – 5925 – 6425 MHz
- UNII 6 – 6425 – 6525 MHz
- UNII 7 – 6525 – 6875 MHz
- UNII 8 – 6875 – 7125 MHz
FCC Part 15 Subpart F sets out the regulations for unlicensed ultra-wideband transmission systems.
FCC Part 15 Subpart G sets out the regulations for Access Broadband over Power Line (Access BPL) devices operating in the 1.705-80 MHz band over medium or low voltage lines. This section outlines the geographical area within which Access BPS operations are not permitted in certain frequencies bands.
FCC Part 15 Subpart H sets out the regulations for Television Band Devices (TVBDs) which are unlicensed intentional radiators operating on available channels in the broadcast television frequency bands at 54–72 MHz, 76–88 MHz, 174–216 MHz, and 470–608 MHz bands.