Goto Section: 15.251 | 15.253 | Table of Contents
FCC 15.252
Revised as of October 2, 2015
Goto Year:2014 |
2016
§ 15.252 Operation of wideband vehicular radar systems within the bands
16.2-17.7 GHz and 23.12-29.0 GHz.
(a) Operation under this section is limited to field disturbance sensors
that are mounted in terrestrial transportation vehicles. Terrestrial use is
limited to earth surface-based, non-aviation applications. Operation within
the 16.2-17.7 GHz band is limited to field disturbance sensors that are used
only for back-up assistance and that operate only when the vehicle is
engaged in reverse.
(1) The −10 dB bandwidth of the fundamental emission shall be located within
the 16.2-17.7 GHz band or within the 23.12-29.0 GHz band, exclusive of the
23.6-24.0 GHz restricted band, as appropriate, under all conditions of
operation including the effects from stepped frequency, frequency hopping or
other modulation techniques that may be employed as well as the frequency
stability of the transmitter over expected variations in temperature and
supply voltage.
(2) The −10 dB bandwidth of the fundamental emission shall be 10 MHz or
greater. For transmitters that employ frequency hopping, stepped frequency
or similar modulation types, measurement of the −10 dB minimum bandwidth
specified in this paragraph shall be made with the frequency hop or step
function disabled and with the transmitter operating continuously at a
fundamental frequency following the provisions of § 15.31(m).
(3) For systems operating in the 23.12-29.0 GHz band, the frequencies at
which the highest average emission level and at which the highest peak level
emission appear shall be greater than 24.075 GHz.
(4) 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. The operation of these devices shall be related to the proper
functioning of the transportation vehicle, e.g., collision avoidance.
(b) Emissions from a transmitter operating under this section shall not
exceed the following equivalent isotropically radiated power (EIRP) density
levels:
(1) For transmitters operating in the 16.2-17.7 GHz band, the RMS average
radiated emissions above 960 MHz from a device operating under the
provisions of this section shall not exceed the following EIRP limits based
on measurements using a 1 MHz resolution bandwidth:
Frequency in MHz EIRP in dBm
960-1610 −75.3
1610-16,200 −61.3
16,200-17,700 −41.3
Above 17,700 −61.3
(2) For transmitters operating in the 23.12-29.0 GHz band, the RMS average
radiated emissions above 960 MHz from a device operating under the
provisions of this section shall not exceed the following EIRP limits based
on measurements using a 1 MHz resolution bandwidth:
Frequency in MHz EIRP in dBm
960-1610 −75.3
1610-23,120 −61.3
23,120-23,600 −41.3
23,600-24,000 −61.3
24,000-29,000 −41.3
Above 29,000 —61.3
(3) In addition to the radiated emission limits specified in the tables in
paragraphs (b)(1) and (b)(2) of this section, transmitters operating under
the provisions of this section shall not exceed the following RMS average
EIRP 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
(4) 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 and this 50 MHz bandwidth must be contained within the
16.2-17.7 GHz band or the 24.05-29.0 GHz band, as appropriate. The peak EIRP
limit is 20 log (RBW/50) dBm where RBW is the resolution bandwidth in MHz
employed by the measurement instrument. RBW shall not be lower than 1 MHz or
greater than 50 MHz. Further, RBW shall not be greater than the −10 dB
bandwidth of the device under test. For transmitters that employ frequency
hopping, stepped frequency or similar modulation types, measurement of the
−10 dB minimum bandwidth specified in this paragraph shall be made with the
frequency hop or step function disabled and with the transmitter operating
continuously at a fundamental frequency. The video bandwidth of the
measurement instrument shall not be less than RBW. The limit on peak
emissions applies to the 50 MHz bandwidth centered on the frequency at which
the highest level radiated emission occurs. If RBW is greater than 3 MHz,
the application for certification shall contain a detailed description of
the test procedure, the instrumentation employed in the testing, and the
calibration of the test setup.
(5) Radiated emissions at or below 960 MHz shall not exceed the emission
levels in § 15.209.
(6) Emissions from digital circuitry used to enable the operation of the
transmitter may comply with the limits in § 15.209 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) , 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 of this part. 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.
(c) Measurement procedures:
(1) All emissions at and below 960 MHz are based on measurements employing a
CISPR quasi-peak detector. Unless otherwise specified, all RMS average
emission levels specified in this section are to be measured utilizing a 1
MHz resolution bandwidth with a one millisecond dwell over each 1 MHz
segment. The frequency span of the analyzer should equal the number of
sampling bins times 1 MHz and the sweep rate of the analyzer should equal
the number of sampling bins times one millisecond. The provision in
§ 15.35(c) that allows emissions to be averaged over a 100 millisecond period
does not apply to devices operating under this section. The video bandwidth
of the measurement instrument shall not be less than the resolution
bandwidth and trace averaging shall not be employed. The RMS average
emission measurement is to be repeated over multiple sweeps with the
analyzer set for maximum hold until the amplitude stabilizes.
(2) The peak emission measurement is to be repeated over multiple sweeps
with the analyzer set for maximum hold until the amplitude stabilizes.
(3) For transmitters that employ frequency hopping, stepped frequency or
similar modulation types, the peak emission level measurement, the
measurement of the RMS average emission levels, the measurement to determine
the center frequency, and the measurement to determine the frequency at
which the highest level emission occurs shall be made with the frequency hop
or step function active. Gated signals may be measured with the gating
active. The provisions of § 15.31(c) continue to apply to transmitters that
employ swept frequency modulation.
(4) The −10 dB bandwidth is based on measurement using a peak detector, a 1
MHz resolution bandwidth, and a video bandwidth greater than or equal to the
resolution bandwidth.
(5) Alternative measurement procedures may be considered by the Commission.
[ 70 FR 6775 , Feb. 9, 2005]
return arrow Back to Top
Goto Section: 15.251 | 15.253
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