RF Exposure

FCC ID: WHBBMWHUS

RF Exposure Info

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FCCID_2480720

Mobile Appliance, Inc. Head-Up Screen BMW Head-Up Screen Appendix 11. RF Exposure Requirement 1.Limits According to FCC 1.1310: The criteria listed in the following table shall be used to evaluate the environment impact of human exposure to radio frequency (RF) radiation as specified in 1.1307(b) LIMITS FOR MAXIMUM PERMISSIBLE EXPOSURE (MPE) Frequency Electric Field Magnetic Field Power Density Average Time Range (MHz) Strength(V/m) Strength (A/m) (mW/cm2) (Minutes) (A) Limits for Occupational/ Control Exposures 300-1500 - - F/300 6 1500-100,000 - - 5 6 (B) Limits for General Population/ Uncontrolled Exposures 300-1500 - - F/1500 6 1500-100,000 - - 1 30 F= Frequency in MHz Friis Formula Friis transmission formula: Pd = (Pout*G)/(4*pi*r2) Where Pd = power density in mW/ cm 2 Pout = output power to antenna in mW G = gain of antenna in linear scale Pi = 3.1416 R = distance between observation point and center of the radiator in cm Pd id the limit of MPE, 1 mW/ cm 2 . If we know the maximum gain of the antenna and the total power input to the antenna, through the calculation, we will know the distance r where the MPE limit is reached. 2.Test Procedure Software provided by client enabled the EUT to transmit and receive data at lowest, middle and highest channel individually. The temperature and related humidity: 20℃and 57％ RH. RF Exposure Report Issue Date : November 13, 2014

Mobile Appliance, Inc. Head-Up Screen BMW Head-Up Screen 3.Test Result of RF Exposure Evaluation Operating mode Frequency RF Output Power(dBm) 802.11b 2412 4.6 802.11b 2437 3.7 802.11b 2462 3.0 802.11g 2412 4.8 802.11g 2437 3.8 802.11g 2462 3.2 802.11n(20MHz) 2412 4.5 802.11n(20MHz) 2437 3.7 802.11n(20MHz) 2462 3.0 Maximum RF Power=4.8dBm+3.5dBi=8.3dBm=6.76mW 6.76/(4*3.14*400)=0.00135 Power Density at R = Frequency Band(MHz) Maximum RF Power(mW) 20cm(mW/ cm 2 ) 2412-2462 6.76 0.00135 Note: The power density Pd (4th column) at a distance of 20 cm calculated from the Friis transmission formula is far below the limit of 1 mW/ cm 2 . RF Exposure Report Issue Date : November 13, 2014


Document Created: 2014-12-17 20:22:28
Document Modified: 2014-12-17 20:22:28
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