§ 15.109   Radiated emission limits.

   (a) Except for Class A digital devices, the field strength of radiated
   emissions from unintentional radiators at a distance of 3 meters shall not
   exceed the following values:
   Frequency of emission (MHz) Field strength (microvolts/meter)
   30-88                                                     100
   88-216                                                    150
   216-960                                                   200
   Above 960                                                 500

   (b) The field strength of radiated emissions from a Class A digital device,
   as determined at a distance of 10 meters, shall not exceed the following:
   Frequency of emission (MHz) Field strength (microvolts/meter)
   30-88                                                      90
   88-216                                                    150
   216-960                                                   210
   Above 960                                                 300

   (c) In the emission tables above, the tighter limit applies at the band
   edges. Sections 15.33 and 15.35 which specify the frequency range over which
   radiated emissions are to be measured and the detector functions and other
   measurement standards apply.

   (d) For CB receivers, the field strength of radiated emissions within the
   frequency range of 25-30 MHz shall not exceed 40 microvolts/meter at a
   distance of 3 meters. The field strength of radiated emissions above 30 MHz
   from such devices shall comply with the limits in paragraph (a) of this
   section.

   (e)  Carrier  current systems used as unintentional radiators or other
   unintentional radiators that are designed to conduct their radio frequency
   emissions via connecting wires or cables and that operate in the frequency
   range of 9 kHz to 30 MHz, including devices that deliver the radio frequency
   energy to transducers, such as ultrasonic devices not covered under part 18
   of  this  chapter,  shall comply with the radiated emission limits for
   intentional radiators provided in § 15.209 for the frequency range of 9 kHz
   to 30 MHz. As an alternative, carrier current systems used as unintentional
   radiators and operating in the frequency range of 525 kHz to 1705 kHz may
   comply  with  the  radiated emission limits provided in § 15.221(a). At
   frequencies above 30 MHz, the limits in paragraph (a), (b), or (g) of this
   section, as appropriate, apply.

   (f) For a receiver which employs terminals for the connection of an external
   receiving antenna, the receiver shall be tested to demonstrate compliance
   with the provisions of this section with an antenna connected to the antenna
   terminals unless the antenna conducted power is measured as specified in
   § 15.111(a).  If  a permanently attached receiving antenna is used, the
   receiver shall be tested to demonstrate compliance with the provisions of
   this section.

   (g) As an alternative to the radiated emission limits shown in paragraphs
   (a) and (b) of this section, digital devices may be shown to comply with the
   standards contained in Third Edition of the International Special Committee
   on  Radio  Interference  (CISPR),  Pub.  22,  “Information  Technology
   Equipment—Radio  Disturbance  Characteristics—Limits  and  Methods  of
   Measurement” (incorporated by reference, see § 15.38). In addition:

   (1) The test procedure and other requirements specified in this part shall
   continue to apply to digital devices.

   (2)  If,  in accordance with § 15.33 of this part, measurements must be
   performed above 1000 MHz, compliance above 1000 MHz shall be demonstrated
   with  the  emission  limit in paragraph (a) or (b) of this section, as
   appropriate. Measurements above 1000 MHz may be performed at the distance
   specified in the CISPR 22 publications for measurements below 1000 MHz
   provided  the  limits  in  paragraphs  (a) and (b) of this section are
   extrapolated  to  the new measurement distance using an inverse linear
   distance extrapolation factor (20 dB/decade), e.g., the radiated limit above
   1000 MHz for a Class B digital device is 150 uV/m, as measured at a distance
   of 10 meters.

   (3) The measurement distances shown in CISPR Pub. 22, including measurements
   made in accordance with this paragraph above 1000 MHz, are considered, for
   the purpose of § 15.31(f)(4) of this part, to be the measurement distances
   specified in this part.

   (h) Radar detectors shall comply with the emission limits in paragraph (a)
   of this section over the frequency range of 11.7-12.2 GHz.

   [ 54 FR 17714 , Apr. 25, 1989, as amended at  56 FR 373 , Jan. 4, 1991;  58 FR 51249 , Oct. 1, 1993;  66 FR 19098 , Apr. 13, 2001;  67 FR 48993 , July 29, 2002;
    69 FR 2849 , Jan. 21, 2004;  80 FR 33447 , June 12, 2015]

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