§  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, fC, and the frequency at which
   the highest level emission occurs, fM, 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 § 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, fM. 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 § 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.

   (h) UWB vehicular systems operating in the 22-29 GHz band are subject
   to the transition provisions of § 15.37(l) through (n).

   [ 67 FR 34856 , May 16, 2002, as amended at  70 FR 6776 , Feb. 9, 2005;  82 FR 43871 , Sept. 20, 2017]