Sec.  15.215   Additional provisions to the general radiated emission
limitations.

   

   (a) The regulations in Sec. Sec. 15.217 through 15.257 provide alternatives to
   the general radiated emission limits for intentional radiators
   operating in specified frequency bands. Unless otherwise stated, there
   are no restrictions as to the types of operation permitted under these
   sections.

   (b) In most cases, unwanted emissions outside of the frequency bands
   shown in these alternative provisions must be attenuated to the
   emission limits shown in Sec. 15.209. In no case shall the level of the
   unwanted emissions from an intentional radiator operating under these
   additional provisions exceed the field strength of the fundamental
   emission.

   (c) Intentional radiators operating under the alternative provisions
   to the general emission limits, as contained in Sec. Sec. 15.217 through
   15.257 and in Subpart E of this part, must be designed to ensure that
   the 20 dB bandwidth of the emission, or whatever bandwidth may
   otherwise be specified in the specific rule section under which the
   equipment operates, is contained within the frequency band designated
   in the rule section under which the equipment is operated. The
   requirement to contain the designated bandwidth of the emission within
   the specified frequency band includes the effects from frequency
   sweeping, frequency hopping and other modulation techniques that may
   be employed as well as the frequency stability of the transmitter over
   expected variations in temperature and supply voltage. If a frequency
   stability is not specified in the regulations, it is recommended that
   the fundamental emission be kept within at least the central 80% of
   the permitted band in order to minimize the possibility of out-of-band
   operation.

   [ 54 FR 17714 , Apr. 25, 1989, as amended at  62 FR 45333 , Aug. 27, 1997;
    67 FR 34855 , May 16, 2002;  69 FR 3265 , Jan. 23, 2004;  70 FR 6774 , Feb.
   9, 2005]