RF Exposure Info

FCC ID: U2M-SR97908002

RF Exposure Info

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FCCID_959996

FCC ID: U2M-SR97908002 RF EXPOSURE REPORT REPORT NO.: SA970519L11 MODEL NO.: ESR-9750G ACCORDING: FCC Guidelines for Human Exposure IEEE C95.1 APPLICANT: Senao Networks Inc. ADDRESS: 3F, No. 529, Chung Cheng Rd., Hsintien, Taipei, Taiwan, R.O.C. ISSUED BY: Advance Data Technology Corporation LAB ADDRESS: 47 14th Lin, Chiapau Tsun, Linko, Taipei, Taiwan, R.O.C. TEST LOCATION: No. 19, Hwa Ya 2nd Rd., Kueishan, Taoyuan, Taiwan, R.O.C. Report No: SA970519L11 1

FCC ID: U2M-SR97908002 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. 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 (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 EXPOSURE 300-1500 … … F/1500 30 1500-100,000 … … 1.0 30 F = Frequency in MHz Report No: SA970519L11 2

FCC ID: U2M-SR97908002 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 r. 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. 5. 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 with the antenna should be included in users manual. So, this device is classified as Mobile Device. Report No: SA970519L11 3

FCC ID: U2M-SR97908002 6. TEST RESULTS 6.1 ANTENNA GAIN The maximum Gain measured in Fully Anechoic Chamber is 2dBi or 1.584893(numeric). 6.2 OUTPUT POWER INTO ANTENNA & RF EXPOSURE VALUE AT DISTANCE 20cm: 802.11b DSSS MODULATION PEAK PEAK LIMIT OF CHANNEL POWER POWER POWER POWER CHANNEL FREQUENCY DENSITY OUTPUT OUTPUT DENSITY (MHz) (mW/cm2) (mW) (dBm) (mW/cm2) 1 2412 50.234 17.01 0.016 1.0 6 2437 63.387 18.02 0.020 1.0 11 2462 63.533 18.03 0.020 1.0 802.11g OFDM MODULATION PEAK PEAK LIMIT OF CHANNEL POWER POWER POWER POWER CHANNEL FREQUENCY DENSITY OUTPUT OUTPUT DENSITY (MHz) (mW/cm2) (mW) (dBm) (mW/cm2) 1 2412 79.616 19.01 0.025 1.0 6 2437 80.168 19.04 0.025 1.0 11 2462 79.983 19.03 0.025 1.0 Report No: SA970519L11 4

FCC ID: U2M-SR97908002 DRAFT 802.11n (20MHz) OFDM MODULATION PEAK POWER OUTPUT TOTAL TOTAL LIMIT OF CHANNEL POWER (dBm) PEAK PEAK POWER CHANNEL FREQUENCY DENSITY POWER POWER DENSITY (MHz) (mW/cm2) CHAIN 0 CHAIN 1 (mW) (dBm) (mW/cm2) 1 2412 17.03 17.07 101.399 20.06 0.032 1.0 6 2437 19.08 19.00 160.342 22.05 0.051 1.0 11 2462 15.08 15.03 64.053 18.07 0.020 1.0 DRAFT 802.11n (40MHz) OFDM MODULATION PEAK POWER OUTPUT TOTAL TOTAL LIMIT OF CHANNEL POWER (dBm) PEAK PEAK POWER CHANNEL FREQUENCY DENSITY POWER POWER DENSITY (MHz) (mW/cm2) CHAIN 0 CHAIN 1 (mW) (dBm) (mW/cm2) 1 2422 13.76 12.84 42.999 16.33 0.014 1.0 4 2437 15.04 15.11 64.349 18.09 0.020 1.0 7 2452 13.50 13.13 42.946 16.33 0.014 1.0 Report No: SA970519L11 5


Document Created: 2008-06-24 17:41:20
Document Modified: 2008-06-24 17:41:20
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