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FCC Part 15 Radio Frequency Devices
Section 15.109

The Federal Communications Commission (FCC) is the authority in the United States of America that creates and enforces the use of airwaves throughout the entire radio frequency spectrum. This group of documents contains the entirety of the FCC Part 15 regulations that concern unlicensed radio frequency devices. As with all government documents, this material is in the public domain and may be freely copied so long as the content is not changed. This copy is provided as a convenience for RF Cafe visitors. 

Click here for the Table of Contents.
[Code of Federal Regulations]
[Title 47, Volume 1]
[Revised as of October 1, 2008]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR15.109]
[Page 769-770]
 
                       TITLE 47--TELECOMMUNICATION
 
              CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION
 
PART 15_RADIO FREQUENCY DEVICES--Table of Contents
 
                    Subpart B_Unintentional Radiators
 
Sec. 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:
------------------------------------------------------------------------
                                                                Field
                                                              strength
                Frequency of emission (MHz)                 (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:
------------------------------------------------------------------------
                                                                Field
                                                              strength
                Frequency of emission (MHz)                 (microvolts/
                                                               meter)
------------------------------------------------------------------------
30-88.....................................................           90
88-216....................................................          150
216-960...................................................          210
Above 960.................................................          300
------------------------------------------------------------------------
[[Page 770]]
    (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 Sec. 
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 Sec. 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 Sec. 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 
Sec. 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 Sec. 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 Sec. 15.31(f)(4) of this part, to be the 
measurement distances specified in this part.
    (4) If the radiated emissions are measured to demonstrate compliance 
with the alternative standards in this paragraph, compliance must also 
be demonstrated with the conducted limits shown in Sec. 15.107(e).
    (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]



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