§ 15.255   Operation within the band 57-64 GHz.

   (a) Operation under the provisions of this section is not permitted for the
   following products:

   (1) Equipment used on aircraft or satellites.

   (2) Field disturbance sensors, including vehicle radar systems, unless the
   field disturbance sensors are employed for fixed operation. For the purposes
   of this section, the reference to fixed operation includes field disturbance
   sensors installed in fixed equipment, even if the sensor itself moves within
   the equipment.

   (b)  Within  the  57-64 GHz band, emission levels shall not exceed the
   following equivalent isotropically radiated power (EIRP):

   (1) Products other than fixed field disturbance sensors shall comply with
   one  of the following emission limits, as measured during the transmit
   interval:

   (i) Except as indicated in paragraph (b)(1)(ii) of this section, the average
   power of any emission shall not exceed 40 dBm and the peak power of any
   emission shall not exceed 43 dBm.

   (ii) For transmitters located outdoors, the average power of any emission
   shall not exceed 82 dBm minus 2 dB for every dB that the antenna gain is
   less than 51 dBi. The peak power of any emission shall not exceed 85 dBm
   minus 2 dB for every dB that the antenna gain is less than 51 dBi. The
   provisions of § 15.204(c)(2) and (c)(4) of this part that permit the use of
   different antennas of the same type and of equal or less directional gain do
   not apply to intentional radiator systems operating under this provision. In
   lieu thereof, intentional radiator systems shall be certified using the
   specific antenna(s) with which the system will be marketed and operated.
   Compliance testing shall be performed using the highest gain and the lowest
   gain antennas for which certification is sought and with the intentional
   radiator  operated  at  its  maximum available output power level. The
   responsible party, as defined in § 2.909 of this chapter, shall supply a list
   of acceptable antennas with the application for certification.

   (2) For fixed field disturbance sensors that occupy 500 MHz or less of
   bandwidth and that are contained wholly within the frequency band 61.0-61.5
   GHz,  the  average power of any emission, measured during the transmit
   interval, shall not exceed 40 dBm, and the peak power of any emission shall
   not exceed 43 dBm. In addition, the average power of any emission outside of
   the 61.0-61.5 GHz band, measured during the transmit interval, but still
   within the 57-64 GHz band, shall not exceed 10 dBm, and the peak power of
   any emission shall not exceed 13 dBm.

   (3) For fixed field disturbance sensors other than those operating under the
   provisions  of  paragraph (b)(2) of this section, the peak transmitter
   conducted output power shall not exceed −10 dBm and the peak EIRP level
   shall not exceed 10 dBm.

   (4)  The  peak  power shall be measured with an RF detector that has a
   detection bandwidth that encompasses the 57-64 GHz band and has a video
   bandwidth  of  at  least  10 MHz. The average emission levels shall be
   calculated based on the measured peak levels, over the actual time period
   during which transmission occurs. Measurement procedures that have been
   found to be acceptable to the Commission in accordance with § 2.947 of this
   chapter may be used to demonstrate compliance.

   (c) Limits on spurious emissions:

   (1) The power density of any emissions outside the 57-64 GHz band shall
   consist solely of spurious emissions.

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

   (3) Between 40 GHz and 200 GHz, the level of these emissions shall not
   exceed 90 pW/cm2 at a distance of 3 meters.

   (4) The levels of the spurious emissions shall not exceed the level of the
   fundamental emission.

   (d)   Only   spurious   emissions   and  transmissions  related  to  a
   publicly-accessible coordination channel, whose purpose is to coordinate
   operation between diverse transmitters with a view towards reducing the
   probability of interference throughout the 57-64 GHz band, are permitted in
   the 57-57.05 GHz band.

   Note  to paragraph (d): The 57-57.05 GHz is reserved exclusively for a
   publicly-accessible coordination channel. The development of standards for
   this channel shall be performed pursuant to authorizations issued under part
   5 of this chapter.

   (e)  Except  as  specified  paragraph (e)(1) of this section, the peak
   transmitter conducted output power shall not exceed 500 mW. Depending on the
   gain of the antenna, it may be necessary to operate the intentional radiator
   using a lower peak transmitter output power in order to comply with the EIRP
   limits specified in paragraph (b) of this section.

   (1) Transmitters with an emission bandwidth of less than 100 MHz must limit
   their peak transmitter conducted output power to the product of 500 mW times
   their  emission bandwidth divided by 100 MHz. For the purposes of this
   paragraph, emission bandwidth is defined as the instantaneous frequency
   range occupied by a steady state radiated signal with modulation, outside
   which the radiated power spectral density never exceeds 6 dB below the
   maximum radiated power spectral density in the band, as measured with a 100
   kHz resolution bandwidth spectrum analyzer. The center frequency must be
   stationary during the measurement interval, even if not stationary during
   normal operation (e.g., for frequency hopping devices).

   (2) Peak transmitter conducted output power shall be measured with an RF
   detector that has a detection bandwidth that encompasses the 57-64 GHz band
   and that has a video bandwidth of at least 10 MHz. Measurement procedures
   that have been found to be acceptable to the Commission in accordance with
   § 2.947 of this chapter may be used to demonstrate compliance.

   (3)  For  purposes  of  demonstrating  compliance with this paragraph,
   corrections to the transmitter conducted output power may be made due to the
   antenna and circuit loss.

   (f) Frequency stability. 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.

   (g) 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.

   (h)  Any  transmitter  that  has  received the necessary FCC equipment
   authorization under the rules of this chapter may be mounted in a group
   installation  for  simultaneous  operation  with  one  or  more  other
   transmitter(s) that have received the necessary FCC equipment authorization,
   without any additional equipment authorization. However, no transmitter
   operating under the provisions of this section may be equipped with external
   phase-locking inputs that permit beam-forming arrays to be realized.

   [ 63 FR 42279 , Aug. 7, 1998, as amended at  66 FR 7409 , Jan. 23, 2001;  68 FR 68547 , Dec. 9, 2003;  78 FR 59850 , Sept. 30, 2013]

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