Goto Section: 15.255 | 15.257 | Table of Contents
FCC 15.256
Revised as of October 2, 2015
Goto Year:2014 |
2016
§ 15.256 Operation of level probing radars within the bands 5.925-7.250 GHz,
24.05-29.00 GHz, and 75-85 GHz.
(a) Operation under this section is limited to level probing radar (LPR)
devices.
(b) LPR devices operating under the provisions of this section shall utilize
a dedicated or integrated transmit antenna, and the system shall be
installed and maintained to ensure a vertically downward orientation of the
transmit antenna's main beam.
(c) LPR devices operating under the provisions of this section shall be
installed only at fixed locations. The LPR device shall not operate while
being moved, or while inside a moving container.
(d) Hand-held applications are prohibited.
(e) Marketing to residential consumers is prohibited.
(f) The fundamental bandwidth of an LPR emission is defined as the width of
the signal between two points, one below and one above the center frequency,
outside of which all emissions are attenuated by at least 10 dB relative to
the maximum transmitter output power when measured in an equivalent
resolution bandwidth.
(1) The minimum fundamental emission bandwidth shall be 50 MHz for LPR
operation under the provisions of this section.
(2) LPR devices operating under this section must confine their fundamental
emission bandwidth within the 5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85
GHz bands under all conditions of operation.
(g) Fundamental emissions limits. (1) All emission limits provided in this
section are expressed in terms of Equivalent Isotropic Radiated Power
(EIRP).
(2) The EIRP level is to be determined from the maximum measured power
within a specified bandwidth.
(i) The EIRP in 1 MHz is computed from the maximum power level measured
within any 1-MHz bandwidth using a power averaging detector;
(ii) The EIRP in 50 MHz is computed from the maximum power level measured
with a peak detector in a 50-MHz bandwidth centered on the frequency at
which the maximum average power level is realized and this 50 MHz bandwidth
must be contained within the authorized operating bandwidth. For a RBW less
than 50 MHz, the peak EIRP limit (in dBm) is reduced by 20 log(RBW/50) dB
where RBW is the resolution bandwidth in megahertz. The RBW shall not be
lower than 1 MHz or greater than 50 MHz. The video bandwidth of the
measurement instrument shall not be less than the RBW. If the RBW is greater
than 3 MHz, the application for certification filed shall contain a detailed
description of the test procedure, calibration of the test setup, and the
instrumentation employed in the testing.
(3) The EIRP limits for LPR operations in the bands authorized by this rule
section are provided in Table 1. The emission limits in Table 1 are based on
boresight measurements (i.e., measurements performed within the main beam of
an LPR antenna).
Table 1—LPR EIRP Emission Limits
Frequency band of operation
(GHz) Average
emission limit
(EIRP in dBm measured in
1 MHz) Peak
emission limit
(EIRP in dBm
measured in
50 MHz)
5.925-7.250 −33 7
24.05-29.00 −14 26
75-85 −3 34
(h) Unwanted emissions limits. Unwanted emissions from LPR devices shall not
exceed the general emission limit in § 15.209 of this chapter.
(i) Antenna beamwidth. (A) LPR devices operating under the provisions of
this section within the 5.925-7.250 GHz and 24.05-29.00 GHz bands must use
an antenna with a −3 dB beamwidth no greater than 12 degrees.
(B) LPR devices operating under the provisions of this section within the
75-85 GHz band must use an antenna with a −3 dB beamwidth no greater than 8
degrees.
(j) Antenna side lobe gain. LPR devices operating under the provisions of
this section must limit the side lobe antenna gain relative to the main beam
gain for off-axis angles from the main beam of greater than 60 degrees to
the levels provided in Table 2.
Table 2—Antenna Side Lobe Gain Limits
Frequency range
(GHz) Antenna side
lobe gain
limit relative
to main
beam gain
(dB)
5.925-7.250 −22
24.05-29.00 −27
75-85 −38
(k) Emissions from digital circuitry used to enable the operation of the
transmitter may comply with the limits in § 15.209 of this chapter provided
it can be clearly demonstrated that those emissions are due solely to
emissions from digital circuitry contained within the transmitter and the
emissions are not intended to be radiated from the transmitter's antenna.
Emissions from associated digital devices, as defined in § 15.3(k) of this
part, e.g., emissions from digital circuitry used to control additional
functions or capabilities other than the operation of the transmitter, are
subject to the limits contained in subpart B, part 15 of this chapter.
Emissions from these digital circuits shall not be employed in determining
the −10 dB bandwidth of the fundamental emission or the frequency at which
the highest emission level occurs.
(l) Measurement procedures. (1) Radiated measurements of the fundamental
emission bandwidth and power shall be made with maximum main-beam coupling
between the LPR and test antennas (boresight).
(2) Measurements of the unwanted emissions radiating from an LPR shall be
made utilizing elevation and azimuth scans to determine the location at
which the emissions are maximized.
(3) All emissions at and below 1,000 MHz except 9-90 kHz and 110-490 kHz
bands are based on measurements employing a CISPR quasi-peak detector.
(4) The fundamental emission bandwidth measurement shall be made using a
peak detector with a resolution bandwidth of 1 MHz and a video bandwidth of
at least 3 MHz.
(5) The provisions in § 15.35(b) and (c) of this part that require emissions
to be averaged over a 100 millisecond period and that limits the peak power
to 20 dB above the average limit do not apply to devices operating under
paragraphs (a) through (l) of this section.
(6) Compliance measurements for minimum emission bandwidth of
frequency-agile LPR devices shall be performed with any related frequency
sweep, step, or hop function activated.
(7) Compliance measurements shall be made in accordance with the specific
procedures published or otherwise authorized by the Commission.
[ 79 FR 12678 , Mar. 6, 2014]
return arrow Back to Top
Goto Section: 15.255 | 15.257
Goto Year: 2014 |
2016
CiteFind - See documents on FCC website that
cite this rule
Want to support this service?
Thanks!
Report errors in
this rule. Since these rules are converted to HTML by machine, it's possible errors have been made. Please
help us improve these rules by clicking the Report FCC Rule Errors link to report an error.
hallikainen.com
Helping make public information public