§  15.253   Operation within the bands 46.7–46.9 GHz and 76.0–77.0 GHz.

   (a) Operation within the bands 46.7–46.9 GHz and 76.0–77.0 GHz is
   restricted to vehicle-mounted field disturbance sensors used as vehicle
   radar systems. The transmission of additional information, such as
   data, is permitted provided the primary mode of operation is as a
   vehicle-mounted field disturbance sensor. Operation under the
   provisions of this section is not permitted on aircraft or satellites.

   (b) The radiated emission limits within the bands 46.7–46.9 GHz and
   76.0–77.0 GHz are as follows:

   (1) If the vehicle is not in motion, the power density of any emission
   within the bands specified in this section shall not exceed 200 nW/cm^2
   at a distance of 3 meters from the exterior surface of the radiating
   structure.

   (2) For forward-looking vehicle-mounted field disturbance sensors, if
   the vehicle is in motion the power density of any emission within the
   bands specified in this section shall not exceed 60 μW/cm^2 at a
   distance of 3 meters from the exterior surface of the radiating
   structure.

   (3) For side-looking or rear-looking vehicle-mounted field disturbance
   sensors, if the vehicle is in motion the power density of any emission
   within the bands specified in this section shall not exceed 30 μW/cm^2
   at a distance of 3 meters from the exterior surface of the radiating
   structure.

   (c) The power density of any emissions outside the operating band shall
   consist solely of spurious emissions and shall not exceed the
   following:

   (1) Radiated emissions below 40 GHz shall not exceed the general limits
   in § 15.209.

   (2) Radiated emissions outside the operating band and between 40 GHz
   and 200 GHz shall not exceed the following:

   (i) For vehicle-mounted field disturbance sensors operating in the band
   46.7–46.9 GHz: 2 pW/cm^2 at a distance of 3 meters from the exterior
   surface of the radiating structure.

   (ii) For forward-looking vehicle-mounted field disturbance sensors
   operating in the band 76–77 GHz: 600 pW/cm^2 at a distance of 3 meters
   from the exterior surface of the radiating structure.

   (iii) For side-looking or rear-looking vehicle-mounted field
   disturbance sensors operating in the band 76–77 GHz: 300 pW/cm^2 at a
   distance of 3 meters from the exterior surface of the radiating
   structure.

   (3) For radiated emissions above 200 GHz from field disturbance sensors
   operating in the 76–77 GHz band: the power density of any emission
   shall not exceed 1000 pW/cm^2 at a distance of 3 meters from the
   exterior surface of the radiating structure.

   (4) For field disturbance sensors operating in the 76–77 GHz band, the
   spectrum shall be investigated up to 231 GHz.

   (d) The provisions in § 15.35 limiting peak emissions apply.

   (e) Fundamental emissions must be contained within the frequency bands
   specified in this section during all conditions of operation. Equipment
   is presumed to operate over the temperature range −20 to +50 degrees
   celsius with an input voltage variation of 85% to 115% of rated input
   voltage, unless justification is presented to demonstrate otherwise.

   (f) Regardless of the power density levels permitted under this
   section, devices operating under the provisions of this section are
   subject to the radiofrequency radiation exposure requirements specified
   in § § 1.1307(b), 2.1091 and 2.1093 of this chapter, as appropriate.
   Applications for equipment authorization of devices operating under
   this section must contain a statement confirming compliance with these
   requirements for both fundamental emissions and unwanted emissions.
   Technical information showing the basis for this statement must be
   submitted to the Commission upon request.

   [ 61 FR 14503 , Apr. 2, 1996, as amended at  61 FR 41018 , Aug. 7, 1996;  63 FR 42279 , Aug. 7, 1998]