47 CFR 15.35 - Measurement detector functions and bandwidths.
The conducted and radiated emission limits shown in this part are based on the following, unless otherwise specified elsewhere in this part:
(a) On any frequency or frequencies below or equal to 1000 MHz, the limits shown are based on measuring equipment employing a CISPR quasi-peak detector function and related measurement bandwidths, unless otherwise specified. The specifications for the measuring instrument using the CISPR quasi-peak detector can be found in Publication 16 of the International Special Committee on Radio Interference (CISPR) of the International Electrotechnical Commission. As an alternative to CISPR quasi-peak measurements, the responsible party, at its option, may demonstrate compliance with the emission limits using measuring equipment employing a peak detector function, properly adjusted for such factors as pulse desensitization, as long as the same bandwidths as indicated for CISPR quasi-peak measurements are employed.
For pulse modulated devices with a pulse-repetition frequency of 20 Hz or less and for which CISPR quasi-peak measurements are specified, compliance with the regulations shall be demonstrated using measuring equipment employing a peak detector function, properly adjusted for such factors as pulse desensitization, using the same measurement bandwidths that are indicated for CISPR quasi-peak measurements.
(b) Unless otherwise specified, on any frequency or frequencies above 1000 MHz, the radiated emission limits are based on the use of measurement instrumentation employing an average detector function. Unless otherwise specified, measurements above 1000 MHz shall be performed using a minimum resolution bandwidth of 1 MHz. When average radiated emission measurements are specified in this part, including average emission measurements below 1000 MHz, there also is a limit on the peak level of the radio frequency emissions. Unless otherwise specified, e.g., see §§ 15.250, 15.252, 15.253(d), 15.255, 15.256, and 15.509 through 15.519 of this part, the limit on peak radio frequency emissions is 20 dB above the maximum permitted average emission limit applicable to the equipment under test. This peak limit applies to the total peak emission level radiated by the device, e.g., the total peak power level. Note that the use of a pulse desensitization correction factor may be needed to determine the total peak emission level. The instruction manual or application note for the measurement instrument should be consulted for determining pulse desensitization factors, as necessary.
(c) Unless otherwise specified, e.g., §§ 15.255(b), and 15.256(l)(5), when the radiated emission limits are expressed in terms of the average value of the emission, and pulsed operation is employed, the measurement field strength shall be determined by averaging over one complete pulse train, including blanking intervals, as long as the pulse train does not exceed 0.1 seconds. As an alternative (provided the transmitter operates for longer than 0.1 seconds) or in cases where the pulse train exceeds 0.1 seconds, the measured field strength shall be determined from the average absolute voltage during a 0.1 second interval during which the field strength is at its maximum value. The exact method of calculating the average field strength shall be submitted with any application for certification or shall be retained in the measurement data file for equipment subject to notification or verification.
- 47 CFR 15.205 — Restricted Bands of Operation.
- 47 CFR 15.256 — Operation of Level Probing Radars Within the Bands 5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85 GHz.
- 47 CFR 15.233 — Operation Within the Bands 43.71-44.49 MHz, 46.60-46.98 MHz, 48.75-49.51 MHz and 49.66-50.0 MHz.
- 47 CFR 15.253 — Operation Within the Bands 46.7-46.9 GHz and 76.0-77.0 GHz.
- 47 CFR 15.245 — Operation Within the Bands 902-928 MHz, 2435-2465 MHz, 5785-5815 MHz, 10500-10550 MHz, and 24075-24175 MHz.
- 47 CFR 15.250 — Operation of Wideband Systems Within the Band 5925-7250 MHz.
- 47 CFR 15.235 — Operation Within the Band 49.82-49.90 MHz.
- 47 CFR 15.252 — Operation of Wideband Vehicular Radar Systems Within the Bands 16.2-17.7 GHz and 23.12-29.0 GHz.
- 47 CFR 15.243 — Operation in the Band 890-940 MHz.
- 47 CFR 15.241 — Operation in the Band 174-216 MHz.
- 47 CFR 15.237 — Operation in the Bands 72.0-73.0 MHz, 74.6-74.8 MHz and 75.2-76.0 MHz.
- 47 CFR 15.251 — Operation Within the Bands 2.9-3.26 GHz, 3.267-3.332 GHz, 3.339-3.3458 GHz, and 3.358-3.6 GHz.
- 47 CFR 15.249 — Operation Within the Bands 902-928 MHz, 2400-2483.5 MHz, 5725-5875 MHZ, and 24.0-24.25 GHz.
- 47 CFR 15.231 — Periodic Operation in the Band 40.66-40.70 MHz and Above 70 MHz.
- 47 CFR 15.239 — Operation in the Band 88-108 MHz.
- 47 CFR 15.227 — Operation Within the Band 26.96-27.28 MHz.