RF Exposure Info

FCC ID: C3KMN730

RF Exposure Info

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FCCID_338093

FCC ID: C3KMN730




                        RF EXPOSURE REPORT

                               REPORT NO.: RF920529H01
                                MODEL NO.: MN-730


                               ACCORDING: FCC Guidelines for Human Exposure
                                          IEEE C95.1




                        APPLICANT: Microsoft Corporation

                         ADDRESS: One Microsoft Way, Redmond WA 98052-
                                  6399, U.S.A




                    ISSUED BY: Advance Data Technology Corporation

               LAB LOCATION: No. 81-1, Lu Liao Keng, 9 Ling, Wu Lung Tsuen,
                             Chiung Lin Hsiang, Hsin Chu Hsien,
                             Taiwan, R.O.C.




                                                             Lab Code: 200376-0




Report No.: 920529H01                       1

ADT No. 920529H01


FCC ID: C3KMN730




                        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.: 920529H01                        2

ADT No. 920529H01


FCC ID: C3KMN730




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


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 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.




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.: 920529H01                        3

ADT No. 920529H01


FCC ID: C3KMN730




6. Test Results

6.1 Antenna Gain
The maximum Gain measured in Fully Anechoic Chamber are 2Bi or 1.585 (numeric).


6.2 Output Power Into Antenna & RF Exposure value at distance 20cm:
For DSSS:
                     Channel                                         Limit of
                                Output Power to   Power Density
   Channel          Frequency                                     Power Density
                                 Antenna (mW)       (mW/cm2)
                      (MHz)                                         (mW/cm2)
       1               2412         34.041           0.0107            1.0
       6               2437         31.915           0.0101            1.0
      11               2462         29.923           0.0094            1.0

For OFDM:
                     Channel                                         Limit of
                                Output Power to   Power Density
   Channel          Frequency                                     Power Density
                                 Antenna (mW)       (mW/cm2)
                      (MHz)                                         (mW/cm2)
       1               2412         55.208           0.0174            1.0
       6               2437         86.696           0.0273            1.0
      11               2462         67.920           0.0214            1.0




Report No.: 920529H01                     4

ADT No. 920529H01



Document Created: 2003-07-02 10:10:44
Document Modified: 2003-07-02 10:10:44

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