RF Exposure Info

FCC ID: H8NWLL220

RF Exposure Info

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FCCID_298573

FCC ID: H8NWLL220 FCC TEST REPORT REPORT NO.: RF911220R07 MODEL NO.: WLL220 ACCORDING: FCC Guidelines for Human Exposure IEEE C95.1 APPLICANT: ASKEY COMPUTER CORP. ADDRESS: 10F, NO. 119, CHIENKANG RD., CHUNG-HO, TAIPEI TAIWAN R.O.C ISSUED BY: Advance Data Technology Corporation LAB LOCATION: 47 14th Lin, Chiapau Tsun, Linko, Taipei, Taiwan, R.O.C. Lab Code: 200102-0 0528 ILAC MRA ADT No.: 911220R07

FCC ID: H8NWLL220 RF Exposure Measurement (Mobile Device) 1. Introduction In this document, we try to prove the safety of radiation harmfulness to the human body for our product. The limit for Maximum Permissible Exposure (MPE) specified in FCC 1.1310 is followed. The Gain of the antenna used in this product is measured in a Fully Anechoic Chamber (FAC) calibrated for antenna measurement in ADT, 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 a far field assumption, the calculated result of that is an over-prediction for near field power density. We will take that as the worst case to specify the safety range. 2. Classification The antenna of the product, under normal use condition, is at least 20 cm away from the body of the user. Warning statement for keeping 20cm separation distance and the prohibition of operating next to a person has been printed on the users manual. So, this product is classified as the Mobile Device. 3. RF Exposure Limit According to FCC 1.1310: The criteria listed in the following table shall be used to evaluate the environmental impact of human exposure to radio-frequency (RF) radiation as specified in 1.1307(b) ADT No.: 911220R07

FCC ID: H8NWLL220 LIMITS FOR MAXIMUM PERMISSIBLE EXPOSURE (MPE) Frequency Electric Field Magnetic Field Power Density Average Time Range Strength (V/m) Strength (A/m) (mW/cm2) (minutes) (MHz) (A)Limits For Occupational / Control Exposures 300-1500 … … F/300 6 1500-100,000 … … 5 6 (B)Limits For General Population / Uncontrolled Exposure 300-1500 … … F/1500 6 1500-100,000 … … 1.0 30 F = Frequency in MHz 4. Friis Formula Friis 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 center of the radiator in cm Pd is the limit of MPE, 1 mW/cm2. 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. Ref. : David K. Cheng, Field and Wave Electromagnetics, Second Edition, Page 640, Eq. (11-133). 5. EUT Operating condition The software provided by Manufacturer enabled the EUT to transmit and receive data at lowest, middle and highest channel individually. 6. Climate Condition The temperature and related humidity: 20 deg. C and 63 % RH ADT No.: 911220R07

FCC ID: H8NWLL220 7. Test Results 7.1 Antenna Gain The maximum Gain measured in Fully Anechoic Chamber are –0.44dBi or 0.9036(numeric) for 5GHz and 0.39dBi or 1.094(numeric) for 2.4GHz. 7.2 Output Power Into Antenna & RF Exposure Distance : For Part 802.11b: MINIMUM ALLOWABLE CHANNEL OUTPUT POWER TO DISTANCE ( r ) FROM CHANNEL FREQUENCY ANTENNA (mW) SKIN (MHz) (Centi-Meter) 1 2412 41.114 1.892 6 2437 45.708 1.994 11 2462 42.402 1.922 For Part 802.11a: Normal Mode: MINIMUM CHANNEL ALLOWABLE OUTPUT POWER TO CHANNEL FREQUENCY DISTANCE ( r ) FROM ANTENNA (mW) (MHz) SKIN (Centi-Meter) 1 5180 42.169 1.741 4 5240 40.832 1.713 5 5260 43.251 1.763 8 5320 44.565 1.790 9 5745 44.977 1.801 12 5805 51.880 1.934 Turbo Mode: MINIMUM CHANNEL ALLOWABLE OUTPUT POWER TO CHANNEL FREQUENCY DISTANCE ( r ) FROM ANTENNA (mW) (MHz) SKIN (Centi-Meter) 1 5210 47.643 1.851 2 5250 46.131 1.821 3 5290 44.668 1.792 4 5760 45.919 1.817 5 5800 26.668 1.384 The minimum allowable distance is very close to the enclosure of the antenna and is very far away from the human being under normal use condition. ADT No.: 911220R07


Document Created: 2003-01-10 15:45:32
Document Modified: 2003-01-10 15:45:32
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