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FCC Part 15 Radio Frequency Devices
Section 15.249

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. 

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[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: 47CFR15.249]
[Page 822]
                       TITLE 47--TELECOMMUNICATION
                     Subpart C_Intentional Radiators
Sec. 15.249  Operation within the bands 902-928 MHz, 2400-2483.5 MHz,
5725-5875 MHZ, and 24.0-24.25 GHz.
    (a) Except as provided in paragraph (b) of this section, the field 
strength of emissions from intentional radiators operated within these 
frequency bands shall comply with the following:
                                                  Field         Field
                                               strength of   strength of
            Fundamental frequency              fundamental    harmonics
                                              (millivolts/  (microvolts/
                                                 meter)        meter)
902-928 MHz.................................            50           500
2400-2483.5 MHz.............................            50           500
5725-5875 MHz...............................            50           500
24.0-24.25 GHz..............................           250          2500
    (b) Fixed, point-to-point operation as referred to in this paragraph 
shall be limited to systems employing a fixed transmitter transmitting 
to a fixed remote location. Point-to-multipoint systems, omnidirectional 
applications, and multiple co-located intentional radiators transmitting 
the same information are not allowed. Fixed, point-to-point operation is 
permitted in the 24.05-24.25 GHz band subject to the following 
    (1) The field strength of emissions in this band shall not exceed 
2500 millivolts/meter.
    (2) The frequency tolerance of the carrier signal shall be 
maintained within 0.001% of the operating 
frequency over a temperature variation of -20 degrees to +50 degrees C 
at normal supply voltage, and for a variation in the primary supply 
voltage from 85% to 115% of the rated supply voltage at a temperature of 
20 degrees C. For battery operated equipment, the equipment tests shall 
be performed using a new battery.
    (3) Antenna gain must be at least 33 dBi. Alternatively, the main 
lobe beamwidth must not exceed 3.5 degrees. The beamwidth limit shall 
apply to both the azimuth and elevation planes. At antenna gains over 33 
dBi or beamwidths narrower than 3.5 degrees, power must be reduced to 
ensure that the field strength does not exceed 2500 millivolts/meter.
    (c) Field strength limits are specified at a distance of 3 meters.
    (d) Emissions radiated outside of the specified frequency bands, 
except for harmonics, shall be attenuated by at least 50 dB below the 
level of the fundamental or to the general radiated emission limits in 
Sec. 15.209, whichever is the lesser attenuation.
    (e) As shown in Sec. 15.35(b), for frequencies above 1000 MHz, the 
field strength limits in paragraphs (a) and (b) of this section are 
based on average limits. However, the peak field strength of any 
emission shall not exceed the maximum permitted average limits specified 
above by more than 20 dB under any condition of modulation. For point-
to-point operation under paragraph (b) of this section, the peak field 
strength shall not exceed 2500 millivolts/meter at 3 meters along the 
antenna azimuth.
    (f) Parties considering the manufacture, importation, marketing or 
operation of equipment under this section should also note the 
requirement in Sec. 15.37(d).
[54 FR 17714, Apr. 25, 1989, as amended at 55 FR 25095, June 20, 1990; 
67 FR 1625, Jan. 14, 2002]

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