RF exposure evaluation

FCC ID: 2ARWA-BS1301

RF Exposure Info

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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301


                                            RF Exposure Evaluation Report

   1. Product Information

      FCC ID:                                           2ARWA-BS1301
      Product Name                                      Wireless Charging with Bluetooth Speaker
      Model Number                                      BS1301
                                                        Wireless Charger Input: DC 5V 2A or DC 9V 1.67A
      Power Supply
                                                                         Output: 5V 1A or 9V 1.1A
      Modulation Type                                   CW (Continuous Wave)
      Frequency Range                                   110.0 - 205.0 KHz
      Maximum Rated Power of WPT                        10 W
      WPT Operation Frequency                           160.0 KHz
      Antenna Type                                      Coil Antenna
      Hardware version                                  A6
      Software version                                  A2
      Accessories                                       iPhone 8 Plus
      Exposure category                                 General population/uncontrolled environment
      EUT Type                                          Production Unit
      Device Type                                       Mobile Device


   2. Evaluation Method

      Per KDB 680106 D01 Section 3. RF Exposure Requirements;
   1) Consumer wireless power transfer devices approved under Part 18 in some cases have to demonstrate
      compliance with RF exposure requirements. The potential for exposure must be assessed according to
      the operating configurations of the wireless system and the exposure conditions of users and
      bystanders. RF exposure must be evaluated with the client device(s) being charged by the primary at
      maximum output power. The RF exposure requirements must be determined in conjunction with the
      device operating characteristics, according to the mobile and portable exposure requirements in
      Section 2.1091 and Section 2.1093 of the rules. SAR and MPE limits do not cover the frequency range
      for wireless power transfer applications which operate below 100 kHz and 300 kHz respectively;
      therefore, RF exposure compliance needs to be determined with respect to 1.1307 (c) and (d) of the
      FCC rules.
   2) Based on the design and implementation of the power transfer application, it must be clearly identified
      if mobile or portable RF exposure conditions apply. Devices that are installed to provide separation of
      at least 20 cm from users and bystanders may qualify for mobile exposure conditions. For some
      conditions where users and bystanders may be exposed at closer than 20 cm, section 2.1091(d) (4) of
      the rules may apply.
   3) For devices designed for typical desktop applications, such a wireless charging pads, RF exposure
      evaluation should be conducted assuming a user separation distance of 15 cm. E and H field strength
      measurements or numerical modeling may be used to demonstrate compliance. Measurements should
      be made from all sides and the top of the primary/client pair, with the 15 cm measured from the
      center of the probe(s) to the edge of the device. Emissions between 100 kHz to 300 kHz should be
      assessed versus the limits at 300 kHz in Table 1 of Section 1.1310: 614 V/m and 1.63 A/m. A KDB
      inquiry is required to determine the applicable exposure limits below 100 kHz
   4) Portable exposure conditions from 100 kHz to 6 GHz are determined with respect to SAR requirements.


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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

        Existing SAR systems and test procedures are generally intended for measurements above 100 MHz.
        While numerical modeling can be an alternative, the constraints of substantial computational
        resources at low frequencies could introduce further limitations. Under these circumstances, including
        operations below 100 kHz, the Commission may consider a combination of analytical analysis, field
        strength, radiated and conducted power measurements, in conjunction with some limited numerical
        modeling to assess compliance.
   5) Depending on the operating frequency, existing SAR and MPE measurement procedures may be
      adapted to evaluate wireless power transfer devices for compliance with respect to mobile or portable
      exposure conditions. If the grantee or its test lab have any questions regarding RF exposure evaluation
      they should contact the FCC Laboratory with sufficient system operating configuration details to
      determine if RF exposure evaluation is necessary and, if required, how to apply specific test procedures.
      Below 100 MHz, when SAR testing is required and the device is operating at close proximity to persons,
      information on device design, implementation, operating configurations, exposure conditions of users
      and bystanders are needed to determine the evaluation and testing requirements. In addition, the
      influence of nearby objects may also need consideration according to the wireless power transfer
      system implementation; for example, the effects of placing the device, its coils or radiating elements
      on or near metallic surfaces
   6) According to April 2018 TCB Workshop, No need to report E-field measurements. Only H-field required.

      Per KDB 447498 D01 Section 4.3.1 Standalone SAR test exclusion considerations;
   a) For 100 MHz to 6 GHz and test separation distances ≤ 50 mm, the 1-g and 10-g SAR test exclusion
       thresholds are determined by the following:
        [(max. power of channel, including tune-up tolerance, mW) / (min. test separation distance, mm)] ·
        [√f(GHz)] ≤ 3.0 for 1-g SAR, and ≤ 7.5 for 10-g extremity SAR, 30 where
        • f(GHz) is the RF channel transmit frequency in GHz
        • Power and distance are rounded to the nearest mW and mm before calculation
        • The result is rounded to one decimal place for comparison
        • The values 3.0 and 7.5 are referred to as numeric thresholds in step b) below
        The test exclusions are applicable only when the minimum test separation distance is ≤ 50 mm, and for
        transmission frequencies between 100 MHz and 6 GHz. When the minimum test separation distance is
        < 5 mm, a distance of 5 mm according to 4.1 f) is applied to determine SAR test exclusion.
   b) For 100 MHz to 6 GHz and test separation distances > 50 mm, the 1-g and 10-g SAR test exclusion
      thresholds are determined by the following (also illustrated in Appendix B):
        1) {[Power allowed at numeric threshold for 50 mm in step a)] + [(test separation distance – 50
           mm)·(f(MHz)/150)]} mW, for 100 MHz to 1500 MHz
      2) {[Power allowed at numeric threshold for 50 mm in step a)] + [(test separation distance – 50
           mm)·10]} mW, for > 1500 MHz and ≤ 6 GHz
   c) For frequencies below 100 MHz, the following may be considered for SAR test exclusion (also
      illustrated in Appendix C):
        1) For test separation distances > 50 mm and < 200 mm, the power threshold at the corresponding
             test separation distance at 100 MHz in step b) is multiplied by [1 + log(100/f(MHz))]
        2) For test separation distances ≤ 50 mm, the power threshold determined by the equation in c) 1)
             for 50 mm and 100 MHz is multiplied by ½
        3) SAR measurement procedures are not established below 100 MHz.
        When SAR test exclusion cannot be applied, a KDB inquiry is required to determine SAR evaluation
        requirements for any SAR test results below 100 MHz to be acceptable.


         Per KDB 447498 D01 Section 4.3.2 Simultaneous transmission SAR test exclusion considerations;
        When an antenna qualifies for the standalone SAR test exclusion of 4.3.1 and also transmits


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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

        simultaneously with other antennas, the standalone SAR value must be estimated according to the
        following to determine the simultaneous transmission SAR test exclusion criteria:
        1) [(max. power of channel, including tune-up tolerance, mW) / (min. test separation distance,
        mm)]·[√f(GHz)/x] W/kg, for test separation distances ≤ 50 mm; where x = 7.5 for 1-g SAR and x = 18.75
        for 10-g SAR.
        2) 0.4 W/kg for 1-g SAR and 1.0 W/kg for 10-g SAR, when the test separation distance is > 50 mm


        Per KDB 447498 D01 Section 7.2 Transmitters used in mobile device exposure conditions for
        simultaneous transmission operations;
        When one of the following test exclusion conditions is satisfied for all combinations of simultaneous
        transmission configurations, further equipment approval is not required to incorporate transmitter
        modules in host devices that operate in the mixed mobile and portable host platform exposure
        conditions. The grantee is responsible for documenting this according to Class I permissive change
        requirements. Antennas that qualify for standalone SAR test exclusion must apply the estimated
        standalone SAR to determine simultaneous transmission test exclusion.
        a) The [∑ of (the highest measured or estimated SAR for each standalone antenna configuration,
           adjusted for maximum tune-up tolerance) / 1.6 W/kg] + [∑ of MPE ratios] is ≤ 1.0.
        b) The SAR to peak location separation ratios of all simultaneously transmitting antenna pairs
           operating in portable device exposure conditions are all ≤ 0.04, and the [∑ of MPE ratios] is ≤ 1.0.


        When RF exposure test exclusion does not apply, simultaneous transmission evaluation is required for
        mixed mobile device and portable device exposure conditions. For each simultaneous transmission
        configuration, the sum of the MPE ratios for the simultaneously transmitting antennas operating in
        mobile device exposure conditions must be determined according to the calculated/estimated,
        numerically modeled or measured field strengths or power density. For each simultaneous
        transmission configuration, the enlarged zoom scan measurement and volume scan post-processing
        procedures in KDB Publication 865664 D01 must be applied to test the simultaneously transmitting
        antennas operating in portable device exposure conditions. The [(highest measured simultaneous
        transmission SAR, adjusted for maximum tune-up tolerance) / 1.6 W/kg] + [∑ of MPE ratios] must be ≤
        1.0 for each simultaneous transmission configuration; otherwise, a PAG is required for the FCC to
        determine compliance on a case-by-case basis, with respect to antenna-to-antenna and
        antenna-to-user separation, device form factor, operating requirements and exposure conditions, etc.


   3. Evaluation Limit

   3.1 Refer Evaluation Method

        ANSI C95.1–1999: IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency
        Electromagnetic Fields, 3 kHz to 300 GHz.
        FCC KDB publication 680106 D01 RF Exposure Wireless Charging Apps v03: RF Exposure Considerations
        for Low Power Consumer Wireless Power Transfer Applications
        FCC KDB publication 447498 D01 General RF Exposure Guidance v06: RF EXPOSURE PROCEDURES AND
        EQUIPMENT AUTHORIZATION POLICIES FOR MOBILE AND PORTABLE DEVICES
        FCC CFR 47 part1 1.1310: Radiofrequency radiation exposure limits.
        FCC CFR 47 part2 2.1091: Radiofrequency radiation exposure evaluation: mobile devices
        FCC CFR 47 part 18.107: Indusial, Scientific, and Medical Equipment


   3.2 Limit



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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                               FCC ID: 2ARWA-BS1301

          Limits for Maximum Permissible Exposure (MPE)/Controlled Exposure
                 Frequency               Electric Field           Magnetic Field            Power Density            Averaging Time
                Range(MHz)              Strength(V/m)             Strength(A/m)               (mW/cm²)                  (minute)
                                                Limits for Occupational/Controlled Exposure
                   0.3-3.0                     614                      1.63                      *100                         6
                   3.0-30                    1842/f                    4.89/f                    *900/f   2
                                                                                                                               6
                   30-300                     61.4                      0.163                      1.0                         6
                 300-1,500                      /                         /                      f/300                         6
               1,500-100,000                    /                         /                         5                          6

          Limits for Maximum Permissible Exposure (MPE)/Uncontrolled Exposure
                 Frequency               Electric Field           Magnetic Field            Power Density            Averaging Time
                Range(MHz)              Strength(V/m)             Strength(A/m)               (mW/cm²)                  (minute)
                                           Limits for General Population/Uncontrolled Exposure
                  0.3-1.34                     614                      1.63                      *100                         30
                   1.34-30                    824/f                    2.19/f                    *180/f2                       30
                   30-300                     27.5                      0.073                      0.2                         30
                 300-1,500                      /                         /                      f/1500                        30
               1,500-100,000                    /                         /                        1.0                         30

          F=frequency in MHz
          *=Plane-wave equivalent power density


          According to FCC KDB 680106 D01 Section 3. RF Exposure Requirements clause 3 the Emission-Limits
          in the frequency range from 100 KHz to 300 KHz should be assessed versus the limits at 300 KHz in
          Table 1 of CFR 47 – Section1.310 as following (measured distance shall be 15cm from the center of
          the probe to the edge of the device):
                                                      E-filed                          H-filed                         B-filed
                   Frequency                           V/m                              A/m                               uT
              0.3 MHz – 3.0 MHz                         614                            1.613                             2.0
              3.0 MHz – 30 MHz                 824/f (=27.530MHz)               2.19/f (=0.07330MHz)                      --

          A KDB inquire was required to determine/confirm the applicable limits below 100 KHz.




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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

   4. Test Setup Diagram




           For mobile RF exposure condition, due to installation limitations no tests from the underside of the
           charging device are required.


   5. Test Equipment

           Equipment              Manufacturer          Model           Serial no.       Calibrated date         Calibrated Due
    Exposure Level Tester             Narda            ELT-400           N-0713             2018-04-02             2019-04-01
         B-Field Probe                Narda            ELT-400           M-1154             2018-04-11             2019-04-10


   6. RF Exposure Evaluation

   6.1 Standalone WPT Evaluation

   6.1.1     Measurement Procedure

           a) The RF exposure test was performed on 360 degree turn table in anechoic chamber.
           b) The measurement probe was placed at test distance (15cm) which is between the edge of the
           charger and the geometric center of probe.
           c) The turn table was rotated 360d degree to search of highest strength.
           d) The highest emission level was recorded and compared with limit as soon as measurement of each
           points (A, B, C, D, E) were completed.
           e) The EUT were measured according to the dictates of KDB 680106D01v03.




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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

   6.1.2     Equipment Approval Considerations

   The EUT does comply with item 5.2 of KDB 680106 D01v02 as follows table;
    Requirements of KDB 680106 D01                               Yes / No       Description
                                                                                The device operate in the frequency range
    Power transfer frequency is less than 1 MHz                  Yes
                                                                                110.0 KHz - 205.0 KHz
    Output power from each primary coil is less                                 The maximum output power of the
                                                                 Yes
    than 15 watts                                                               primary coil is 10W.
    The transfer system includes only single primary
                                                                                The transfer system includes one primary
    and secondary coils. This includes charging
                                                                                coils and clients that are able to detect and
    systems that may have multiple primary coils                 Yes
                                                                                allow coupling only between individual
    and clients that are able to detect and allow
                                                                                pairs of coils.
    coupling only between individual pairs of coils.
    Client device is placed directly in contact with                            Client device is placed directly in contact
                                                                 Yes
    the transmitter.                                                            with the transmitter.
    Mobile exposure conditions only (portable
    exposure conditions are not covered by this                  Yes            Mobile exposure conditions only
    exclusion).
    The aggregate H-field strengths at 15 cm                                    The aggregate H-field strengths at 15 cm
    surrounding the device and 20 cm above the top                              surrounding the device and 20 cm above
    surface from all simultaneous transmitting coils             Yes            the top surface from all simultaneous
    are demonstrated to be less than 50% of the                                 transmitting coils are less than 50% the
    MPE limit.                                                                  MPE limit.

        In all other cases, unless excluded above, an RF exposure evaluation report must be reviewed and
        accepted through a KDB or PBA inquiry to enable authorization of the equipment. When evaluation is
        required to show compliance; for example, using field strength, power density, SAR measurements or
        computational modeling etc., the specific authorization requirements will be determined based on the
        results of the RF exposure evaluation.


   6.1.3     E and H field Strength

        Operate mode:
   Test Modes:
   TM1           AC/DC Adapter + EUT + BT Speaker + Mobile Phone (Battery Status: <1%)                                   Record
   TM2           AC/DC Adapter + EUT + BT Speaker + Mobile Phone (Battery Status: <50%)                                  Record
   TM3           AC/DC Adapter + EUT + BT Speaker + Mobile Phone (Battery Status: 100%)                                  Record
   Note: All test modes were pre-tested, but we only recorded the worst case in this report.




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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

H-Field Strength at 15 cm from the edges surrounding the EUT and 15cm from the top surface of the EUT
                                            Measured H-Field Strength Values (A/m)                         FCC H-Field       FCC H-Field
Charging      Frequency
                                                                                                            Strength          Strength
 Battery        Range             Test           Test           Test           Test           Test
                                                                                                           50% Limits          Limits
  Level         (MHz)          Position A     Position B     Position C     Position D      Position E
                                                                                                             (A/m)             (A/m)
  1%             0.150           0.101          0.091           0.104          0.114          0.126            0.815             1.63
  50%            0.150           0.098          0.092           0.105          0.098          0.129            0.815             1.63
  99%            0.150           0.083          0.083           0.075          0.070          0.113            0.815             1.63

H-Field Strength at 20cm from the top surface of the EUT
                                                    Measured H-Field Strength                  FCC H-Field               FCC H-Field
Charging Battery       Frequency Range
                                                         Values (A/m)                         Strength 50%             Strength Limits
     Level                  (MHz)
                                                            Test Position E                    Limits (A/m)                (A/m)
        1%                    0.150                              0.092                            0.815                     1.63
       50%                    0.150                              0.093                            0.815                     1.63
       99%                    0.150                              0.085                            0.815                     1.63




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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

   6.1.4     Test Setup Photos

   6.1.4.1 Test Position E-Exposure photo from top surface (20cm)




                                        20cm




                                                                (TM1)

   6.1.4.2     Test Position E-Exposure photo from top surface (15cm)




                                           15cm




                                                                   (TM1)


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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

   6.1.4.3     Test Position A-Exposure photo from side edge surface-Rear




                                                                        15cm




                                                                   (TM1)

   6.1.4.4 Test Position B-Exposure photo from side edge surface-Left




                                                                             15cm




                                                                   (TM1)


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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

   6.1.4.5 Test Position C-Exposure photo from side edge surface-Front




                                                                 15cm




                                                                   (TM1)

   6.1.4.6 Test Position D-Exposure photo from side edge surface-Right




                                                                                    15cm

                                                                   (TM1)


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SHENZHEN LCS COMPLIANCE TESTING LABORATORY LTD.                                                             FCC ID: 2ARWA-BS1301

   7. Conclusion

          The detected emissions with a distance of 20 cm from center of probe to the top surface of EUT and
          15cm from center of probe to edge of EUT are below the limitations according to FCC KDB 680106
          D01 Section 3. RF Exposure Requirement Clause 3.
          The measurement results comply with the FCC Limit per 47 CFR 2.1091 for the uncontrolled RF
          Exposure of mobile exposure conditions.


                                                       Revision History

           Revision                        Issue Date                           Revisions                        Revised By
             000                        February 22, 2019                      Initial Issue                     Gavin Liang




                              .........................END OF REPORT.........................




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Document Created: 2019-05-09 17:13:37
Document Modified: 2019-05-09 17:13:37

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