MPE

FCC ID: 2APU9-391

RF Exposure Info

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FCCID_4234985

                                RF Exposure evaluation


FCC ID: 2APU9-391
According to 447498 D01 General RF Exposure Guidance v06
4.3. General SAR test exclusion guidance
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 calculation31
     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.

30
  This is equivalent to the formula written as: [(max. power of channel, including tune-up tolerance,
mW)/(60/√f(GHz) mW)]·[20 mm/(min. test separation distance, mm)] ≤ 1.0 for 1-g SAR; also see
Appendix A for approximate exclusion threshold numerical values at selected frequencies and
distances.


eirp = pt x gt = (EXd)2/30
where:
 pt = transmitter output power in watts,
 gt = numeric gain of the transmitting antenna (unitless),
E = electric field strength in V/m, ---  10((dBuV/m)/20)/106
d = measurement distance in meters (m)---3m
So pt = (EXd)2/30 x gt




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RF Exposure evaluation
Copied from the FCC test report: clause 9.4 Maximum Peak Output Power


Test Result:
For BLE:
                             Frequency       Reading         Output Power           Limit
     Test Mode
                                  MHz         dBm                mW                 mW
                                  2402         0.80              1.20               1000
    GFSK(BLE)                     2442         0.76              1.19               1000
                                  2480        -2.84              0.52               1000


Note: the antenna gain of 0dB less than 6dBi maximum permission antenna gain value based on

1 watt peak output power limit.


Then we choose Normal mode channel as the worst case of Maximum Peak Output Power:


                             Frequency       Reading         Output Power           Limit
     Test Mode
                                  MHz         dBm                mW                 mW
                                  2402         0.80              1.20               1000
    GFSK(BLE)                     2442         0.76              1.19               1000
                                  2480        -2.84              0.52               1000


EIRP/ dBm= Conducted Max Output Power/ dBm+ Antenna gain /dBi.



General RF Exposure:
(1.20mW )/5.0mm)x √2.402 GHz = 0.37
(1.19mW )/5.0mm)x √2.442 GHz = 0.37
(0.52mW )/5.0mm)x √2.480 GHz = 0.16


SAR requirement: S=3.0
General RF Exposure<3
Then SAR evaluation is not required




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Document Created: 2019-02-25 14:14:02
Document Modified: 2019-02-25 14:14:02

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