§ 90.1215   Power limits.

   The transmitting power of stations operating in the 4940-4990 MHz band must
   not exceed the maximum limits in this section.

   (a)(1) The maximum conducted output power should not exceed:
   Channel bandwidth (MHz) Low power
   maximum conducted
   output power (dBm) High power maximum
   conducted output
   power (dBm)
   1 7 20
   5 14 27
   10 17 30
   15 18.8 31.8
   20 20 33

   (2) High power devices are also limited to a peak power spectral density of
   21 dBm per one MHz. High power devices using channel bandwidths other than
   those listed above are permitted; however, they are limited to peak power
   spectral density of 21 dBm/MHz. If transmitting antennas of directional gain
   greater than 9 dBi are used, both the maximum conducted output power and the
   peak power spectral density should be reduced by the amount in decibels that
   the directional gain of the antenna exceeds 9 dBi. However, high power
   point-to-point  and  point-to-multipoint  operations  (both  fixed and
   temporary-fixed rapid deployment) may employ transmitting antennas with
   directional gain up to 26 dBi without any corresponding reduction in the
   maximum conducted output power or spectral density. Corresponding reduction
   in the maximum conducted output power and peak power spectral density should
   be the amount in decibels that the directional gain of the antenna exceeds
   26 dBi.

   (b) Low power devices are also limited to a peak power spectral density of 8
   dBm per one MHz. Low power devices using channel bandwidths other than those
   listed  above are permitted; however, they are limited to a peak power
   spectral density of 8 dBm/MHz. If transmitting antennas of directional gain
   greater than 9 dBi are used, both the maximum conducted output power and the
   peak power spectral density should be reduced by the amount in decibels that
   the directional gain of the antenna exceeds 9 dBi.

   (c) The maximum conducted output power is measured as a conducted emission
   over  any  interval  of  continuous transmission using instrumentation
   calibrated in terms of an RMS-equivalent voltage. If the device cannot be
   connected directly, alternative techniques acceptable to the Commission may
   be  used.  The  measurement results shall be properly adjusted for any
   instrument limitations, such as detector response times, limited resolution
   bandwidth capability when compared to the emission bandwidth, sensitivity,
   etc., so as to obtain a true maximum conducted output power measurement
   conforming  to  the  definitions in this paragraph for the emission in
   question.

   (d) The peak power spectral density is measured as conducted emission by
   direct connection of a calibrated test instrument to the equipment under
   test. If the device cannot be connected directly, alternative techniques
   acceptable to the Commission may be used. Measurements are made over a
   bandwidth  of  one  MHz or the 26 dB emission bandwidth of the device,
   whichever  is  less.  A resolution bandwidth less than the measurement
   bandwidth can be used, provided that the measured power is integrated to
   show total power over the measurement bandwidth. If the resolution bandwidth
   is approximately equal to the measurement bandwidth, and much less than the
   emission bandwidth of the equipment under test, the measured results shall
   be corrected to account for any difference between the resolution bandwidth
   of the test instrument and its actual noise bandwidth.

   (e) The ratio of the peak excursion of the modulation envelope (measured
   using a peak hold function) to the maximum conducted output power shall not
   exceed 13 dB across any 1 MHz bandwidth or the emission bandwidth whichever
   is less.

   [70 CFR 28467, May 18, 2005, as amended at  74 FR 23803 , May 21, 2009;  74 FR 27455 , June 10, 2009]

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