Sec.  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
    Sec. 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  Sec. 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  Sec.  Sec. 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]