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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