• Frank Gruson commented on 2018-03-02 12:31:11.436:
  ADC Automotive Distance Control Systems GmbH (a Continental Company) fully supports the content of KDB 653005 and would like to add the following comments: 1/ We welcome the clear definition of the term "vehicles" and the fact that generic "fixed radar" and "airborne" applications are excluded without further compatibility studies regarding their interference impact to "Vehicular Radar". 2/ We welcome the clarification of the measurement procedure of the fundamental power levels which allows for the measurement of the fundamental average and peak power levels under normal modulation conditions of the radar sensor, replacing the "frequency stop mode" as mandated previously in FCC part § 15.31(c) which is somehow outdated and difficult to realize with today´s radar equipment (as a "frequency stop mode" does not exist in a modern Vehicular Radar sensor). 3/ We support the detailed definition of the fundamental average power (with emission limit "50dBm") to be interpreted as EIRP "over the total emission bandwidth (occupied or necessary bandwidth) of the transmission" and the proposed measurement procedure which is a measurement in normal operation mode using an RMS detector with RBW = 1 MHz and an integration over the complete bandwidth of the fundamental emission (occupied or necessary bandwidth). This method is well supported by today´s test equipment using the feature "channel power" as e.g. proposed in § 15.405 Cross reference ("A narrower resolution bandwidth can be used, provided that the measured power is integrated over the full reference bandwidth."). We would like to note, that this integration procedure is in agreement with true RMS power meter measurements, but only if the averaging time of the spectrum analyzer (sweep time per spectrum analyzer sweep point) is equal to or larger than 1 radar cycle (typically in the range of 100ms). This means, that a statement about the averaging time should be added to the KDB 653005. 4/ Our understanding is, that the emissions limits of spurious emissions above 1000 MHz are based on measurements employing an average detector with a 1 MHz RBW under normal modulation conditions, as indicated in "§ 2.1053 Measurements required: Field strength of spurious radiation." in section (a) ("Measurements shall be made to detect spurious emissions ... under normal conditions of ... operation" and "... transmitters shall be modulated under the conditions specified in paragraph (c) of § 2.1049, as appropriate.") 5/ We also welcome the clear measurement procedure in "§ 2.1049 Measurements required: Occupied bandwidth." to determine the OBW as the bandwidth which contains 99% of the mean power of the radar emission. We understand that this replaces the previous procedure using a "26dB down marker" of the emission curve using a PEAK detector. 6/ Due to the fact that this KDB refers for the general technical parameters to be measured to sections § 2.1046 through § 2.1057 and that those paragraphs (§ 2.1046 - § 2.1057) are mainly optimized for "radiotelephone transmitters", we propose, that this KDB 653005 is migrated into a new chapter of ANSI C63.26-2015 "American National Standard for Compliance Testing of Transmitters Used in Licensed Radio Services" which states in the ABSTRACT of the current version "... does not consider test methods for requirements specific to ... groundbased radars. The latter equipment may be covered in future revisions of this standard." Adding such a new chapter dedicated to "Vehicular Radar" to ANSI C63.26-2015 is advised, as ANSI C63.10-2013 only relates to "Unlicensed Wireless Devices" (such as part 15 devices) but not to part 95 devices.

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• Mike Heckrotte commented on 2018-03-02 04:06:32.58:
  See attachment View attachment associated with this comment

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• Karsten Geraldy commented on 2018-02-14 11:47:23.136:
  Dear FCC-Team, referring to: (b) The maximum peak power (EIRP) within the 76-81 GHz band shall not exceed 55 dBm based on measurements employing a peak detector with a 1 MHz RBW. ... The second requirement specifies a peak-detected EIRP limit of 55 dBm that cannot be exceeded in any 1 MHz resolution bandwidth (i.e., a peak EIRP spectral density limit of 55 dBm/MHz). The compliance measurement is to be performed by sweeping the transmitted OBW with a positive peak power detector, with peak hold activated, using a 1 MHz RBW. Power integration is not to be used in performing this measurement. According to our experience power meter measurement and RMS channel power function of spectrum analyzers gives well comparable results for the RMS/mean/average EIRP. In case of Peak EIRP of a FMCW signal integration over emission bandwidth is not useful. Doing so this will lead to an EIRP, e.g. 30 dBm peak + 10 log(1G/1M) = 60 dBm Peak EIRP, the device is never able to generate. There Peak power / 1MHz is absolutely correct. In case of pulsed radars integration over emission bandwidth should be done to get correct Peak EIRP values, same as for mean EIRP. What about averaging time during averaging measurements? Does §15.35(c) or equivalent still apply? I couldn't find this information in §95M. Best regards Karsten

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Note: It is important to understand that the staff guidance provided in the KDB is intended to assist the public in following Commission requirements and does not constitute rules. Accordingly, the guidance is not binding on the Commission and will not prevent the Commission from making a different decision in any matter that comes to its attention for resolution.