Sec.  15.515   Technical requirements for vehicular radar systems.

   (a) Operation under the provisions of this section is limited to UWB field
   disturbance sensors mounted in terrestrial transportation vehicles. These
   devices shall operate only when the vehicle is operating, e.g., the engine
   is running. Operation shall occur only upon specific activation, such as
   upon starting the vehicle, changing gears, or engaging a turn signal.

   (b)  The UWB bandwidth of a vehicular radar system operating under the
   provisions of this section shall be contained between 22 GHz and 29 GHz. In
   addition, the center frequency, f[C], and the frequency at which the highest
   level emission occurs, f[M], must be greater than 24.075 GHz.

   (c) Following proper installation, vehicular radar systems shall attenuate
   any  emissions within the 23.6–24.0 GHz band that appear 38 degrees or
   greater above the horizontal plane by 25 dB below the limit specified in
   paragraph (d) of this section. For equipment authorized, manufactured or
   imported on or after January 1, 2005, this level of attenuation shall be 25
   dB for any emissions within the 23.6–24.0 GHz band that appear 30 degrees or
   greater above the horizontal plane. For equipment authorized, manufactured
   or imported on or after January 1, 2010, this level of attenuation shall be
   30 dB for any emissions within the 23.6–24.0 GHz band that appear 30 degrees
   or  greater  above  the  horizontal  plane.  For equipment authorized,
   manufactured  or  imported  on or after January 1, 2014, this level of
   attenuation shall be 35 dB for any emissions within the 23.6–24.0 GHz band
   that appear 30 degrees or greater above the horizontal plane. This level of
   attenuation can be achieved through the antenna directivity, through a
   reduction in output power or any other means.

   (d) The radiated emissions at or below 960 MHz from a device operating under
   the provisions of this section shall not exceed the emission levels in
    Sec. 15.209. The radiated emissions above 960 MHz from a device operating under
   the provisions of this section shall not exceed the following average limits
   when measured using a resolution bandwidth of 1 MHz:
   Frequency in MHz EIRP in dBm
   960–1610               −75.3
   1610–22,000            −61.3
   22,000–29,000          −41.3
   29,000–31,000          −51.3
   Above 31,000           −61.3

   (e) In addition to the radiated emission limits specified in the table in
   paragraph  (d)  of  this section, UWB transmitters operating under the
   provisions of this section shall not exceed the following average limits
   when measured using a resolution bandwidth of no less than 1 kHz:
   Frequency in MHz EIRP in dBm
   1164–1240              −85.3
   1559–1610              −85.3

   (f) There is a limit on the peak level of the emissions contained within a
   50 MHz bandwidth centered on the frequency at which the highest radiated
   emission occurs, f[M]. That limit is 0 dBm EIRP. It is acceptable to employ
   a different resolution bandwidth, and a correspondingly different peak
   emission limit, following the procedures described in  Sec. 15.521.

   (g) The emission levels from devices operating under the provisions of this
   section that employ gated transmissions may be measured with the gating
   active. Measurements made in this manner shall be repeated over multiple
   sweeps  with  the  analyzer  set  for maximum hold until the amplitude
   stabilizes.

   [ 67 FR 34856 , May 16, 2002, as amended at  70 FR 6776 , Feb. 9, 2005]