RF exposure

FCC ID: 2APT7-YN

RF Exposure Info

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FCCID_3864386

BSL18051432080005Y‐ER‐2




                                     RF Exposure Report

FCC ID:2APT7-YN

RF Exposure Measurement

The limit for Maximum Permissible Exposure (MPE) specified in FCC 1.1310 is followed. The gain of the antennas
used in the product is extracted from the Antenna data sheets provided and also the maximum total power input to
the antenna is measured. Through the Friis transmission formula and the maximum gain of the antenna, we can
calculate the distance, away from the product, where the limit of MPE is reached.
Although the Friis Transmission formula is far field assumption, the calculated result of that is an over-prediction
for near field power density. It is taken as worst case to specify the safety range.


RF Exposure Limit

According to FCC 1.1310: The criteria listed in the following table shall be used to evaluate the
environmental impact of the human exposure to radio-frequency (RF) radiation as specified in 1.1307 (b)

Limits for Maximum Permissible Exposure (MPE)


F= Frequency in MHz




   Frequency Range             Electric Field            Magnetic Field              Power Density
   (MHz)                       Strength (V/m)            Strength (A/m)              (mW/cm²)
   Limits for Occupational / controlled Exposures
   300 - 1500                  --                        --                          F/300
   1500 – 100000               --                        --                          5.0
   Limits for General population / Uncontrolled Exposure
   300 - 1500                  --                        --                          F/1500
   1500 – 100000               --                        --                          1.0




                                                        One


BSL18051432080005Y‐ER‐2



 Friss Formula

 Friss Transmission Formula: Pd = (Pout * G) / (4*pi*r²)

 Where
 Pd = power density in mW/cm²
 Pout = output power to antenna in mW
 G = gain of antenna in linear scale
 Pi = 3.1416
 R = Distance between observation point and the center of radiator in cm

 If we know the maximum gain of the antenna and the total output power to the antenna, through calculation, we
 will know MPE value at distance 20cm.

 EUT Operation condition

 EUT was enabled to transmit and receive at lowest, middle and highest channels.

 Classification

 The antenna of this product, under normal use condition, is at least 20cm away from the body of the user. Warning
 statement to the user for keeping at least 20cm or more separation distance from the antenna should be included
 in the User manual. So, this device is classified as Mobile device.

2.4GHz WIFI

ANT Gain
(G)=0+10log(2)=3.01dBi
Numeric gain:2.0
2412-2462MHz:


                            Channel      Output Power        Output Power
        Protocol           Frequency       to Antenna            to Antenna   Power Density      Limit
                                                                                (mW/cm²)       (mW/cm²)
                             (MHz)            (dBm)                 (mW)
        802.11b               2462            19.48                88.72         0.0353          1.000

        802.11g               2462            18.03                67.61         0.0269          1.000

     802.11n HT20             2462            18.27                67.14                         1.000
                                                                                 0.0267
     802.11n HT40             2422            17.82                60.53         0.0241          1.000


Then SAR evaluation is not required




                                                           Two



Document Created: 2018-05-15 19:10:31
Document Modified: 2018-05-15 19:10:31

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