RF Exposure Info

FCC ID: H8NWLF3020

RF Exposure Info

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FCCID_623353

FCC ID: H8NWLF3020 RF EXPOSURE REPORT REPORT NO.: SA941208L13 MODEL NO.: WLF3020 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 ADDRESS: No. 47, 14th Ling, Chia Pau Tsuen, Lin Kou Hsiang 244, Taipei Hsien, Taiwan, R.O.C. TEST LOCATION: No. 19, Hwa Ya 2nd Rd., Wen Hwa Tsuen, Kwei Shan Hsiang, Taoyuan Hsien 333, Taiwan, R.O.C. Report No: SA941208L13 1

FCC ID: H8NWLF3020 RF Exposure Measurement 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. 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) 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 Report No: SA941208L13 2

FCC ID: H8NWLF3020 3. 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 If we know the maximum Gain of the antenna and the total power input to the antenna, through the calculation, we will know the MPE value at distance 20cm. Ref.: David K. Cheng, Field and Wave Electromagnetics, Second Edition, Page 640, Eq. (11-133). 4 EUT Operating condition The software provided by Manufacturer enabled the EUT to transmit and receive data at lowest, middle and highest channel individually. Report No: SA941208L13 3

FCC ID: H8NWLF3020 5 Conclusion No Evaluation Required if power is below this threshold: F(GHz) mW Low 2.402 24.585 High 2.480 Maximum measured transmitter power: Pout (dBm) Pout (mW) Conducted Power 13.08 20.324 EIRP Power 13.55 22.646 *Note: The antenna is PCB antenna with 0.47dBi gain Threshold for no SAR evaluation is 24.585mW Transmitter power is 22.646mW Conclusion: No SAR evaluation required since Transmitter Pout is below FCC threshold Report No: SA941208L13 4


Document Created: 2006-01-25 16:51:00
Document Modified: 2006-01-25 16:51:00
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