RF expo evaluation

FCC ID: 2ASH5R2-JW-720P-433

RF Exposure Info

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FCCID_4435966

RF Exposure Report FCC ID: 2ASH5R2-JW-720P-433 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) 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 Limits for Maximum Permissible Exposure (MPE) F= Frequency in MHz

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. 2.4G WIFI Mode 802.11b/g/n20:2412-2462MHz 802.11n40:2422-2452MHz Detector PEAK 802.11b 16±1dBm 802.11g 16±1dBm 802.11n20 15±1dBm 802.11n40 15±1dBm ANT Gain (G) Antenna gain :1.5dBi (gain of antenna in linear scale=1.413) Protocol ANT Channel Output Output Power Density Limit gain(gain of Frequency(MHz) Power to Power to (mW/cm²) (mW/cm²) antenna in Antenna Antenna linear scale) (dBm) (mW) 802.11b 1.413 2412 17 50.119 0.014 1 802.11g 1.413 2412 17 50.119 0.014 1 802.11n20 1.413 2437 16 39.811 0.011 1 802.11n40 1.413 2422 16 39.811 0.011 1


Document Created: 2019-09-09 19:40:23
Document Modified: 2019-09-09 19:40:23
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