RF Exposure Calculation

FCC ID: H8NPCICARD54

RF Exposure Info

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FCCID_402744

FCC ID: H8NPCICARD54




                   RF EXPOSURE REPORT


                            REPORT NO.: RF920828R01B
                             MODEL NO.: Gigaset PCI Card 54


                            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.




Report No: RF920828R01B                 1


FCC ID: H8NPCICARD54




          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         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: RF920828R01B                      2


FCC ID: H8NPCICARD54




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.



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: RF920828R01B                      3


FCC ID: H8NPCICARD54




6. Test Results

6.1 Antenna Gain
The maximum Gain measured in Fully Anechoic Chamber is 1.8dBi or 1.51 (numeric).

6.2 Output Power Into Antenna & RF Exposure value at distance 20cm:

For 802.11b:
                    Channel                                              Limit of
                                 Output Power to Power Density
   Channel         Frequency                                          Power Density
                                  Antenna (mW)     (mW/cm2)
                     (MHz)                                              (mW/cm2)
       1              2412              31.62              0.009           1.0
       6              2437              30.90              0.009           1.0
      11              2462              31.62              0.009           1.0

For 802.11g:
                    Channel                                              Limit of
                                 Output Power to Power Density
   Channel         Frequency                                          Power Density
                                  Antenna (mW)     (mW/cm2)
                     (MHz)                                              (mW/cm2)
       1              2412              30.90              0.009           1.0
       6              2437              30.20              0.009           1.0
      11              2462              31.62              0.009           1.0




Report No: RF920828R01B                         4



Document Created: 2004-03-01 22:08:22
Document Modified: 2004-03-01 22:08:22

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