RF Exposure Info

FCC ID: RD7-A5020

RF Exposure Info

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FCCID_582654

FCC ID: RD7-A5020




                    RF EXPOSURE REPORT

                         REPORT NO.: SA940629L08
                          MODEL NO.: A5020



                         ACCORDING: FCC Guidelines for Human Exposure
                                    IEEE C95.1


               APPLICANT: AirMagnet, Inc.

                 ADDRESS: 1325 Chesapeake Terrace, Sunnyvale, CA 94089
                          U.S.A.



                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: SA940629L08                   1


FCC ID: RD7-A5020




          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: SA940629L08                       2


FCC ID: RD7-A5020




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

This device is not fixed inside the host equipment, it is connected with host through wire.
So it is easy to be re-located in the place where at least 20cm far 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: SA940629L08                       3


FCC ID: RD7-A5020




6 Test Results

6.1 Antenna Gain


The maximum Gain measured in Fully Anechoic Chamber is 6dBi or 3.981 (numeric) (for
2.4GHz) 8dBi or 6.310 (numeric)(for 5GHz).

6.2 Output Power into Antenna & RF Exposure at Distance 20cm:

802.11b DSSS modulation
Antenna gain: 5dBi
                      Channel                                             Limit of
                                  Output Power to      Power Density
   Channel           Frequency                                         Power Density
                                   Antenna (mW)          (mW/cm2)
                       (MHz)                                             (mW/cm2)
       1                2412           50.816              0.032            1.0
       6                2437           51.168              0.032            1.0
      11                2462           50.350              0.032            1.0


Antenna gain: 2.05dBi
                      Channel                                             Limit of
                                  Output Power to      Power Density
   Channel           Frequency                                         Power Density
                                   Antenna (mW)          (mW/cm2)
                       (MHz)                                             (mW/cm2)
       1                2412           50.816              0.016            1.0
       6                2437           51.168              0.016            1.0
      11                2462           50.350              0.016            1.0

Antenna gain: 6dBi
                      Channel                                             Limit of
                                  Output Power to      Power Density
   Channel           Frequency                                         Power Density
                                   Antenna (mW)          (mW/cm2)
                       (MHz)                                             (mW/cm2)
       1                2412           50.816              0.040            1.0
       6                2437           51.168              0.041            1.0
      11                2462           50.350              0.040            1.0




Report No: SA940629L08                          4


FCC ID: RD7-A5020




802.11g OFDM modulation
Antenna gain: 5dBi
                      Channel                                         Limit of
                                 Output Power to   Power Density
   Channel           Frequency                                     Power Density
                                  Antenna (mW)       (mW/cm2)
                       (MHz)                                         (mW/cm2)
       1                2412         25.293            0.016            1.0
       6                2437         25.586            0.016            1.0
      11                2462         25.410            0.016            1.0


Antenna gain: 2.05dBi
                      Channel                                         Limit of
                                 Output Power to   Power Density
   Channel           Frequency                                     Power Density
                                  Antenna (mW)       (mW/cm2)
                       (MHz)                                         (mW/cm2)
       1                2412         25.293            0.008            1.0
       6                2437         25.586            0.008            1.0
      11                2462         25.410            0.008            1.0

Antenna gain: 6dBi
                      Channel                                         Limit of
                                 Output Power to   Power Density
   Channel           Frequency                                     Power Density
                                  Antenna (mW)       (mW/cm2)
                       (MHz)                                         (mW/cm2)
       1                2412         25.293            0.020            1.0
       6                2437         25.586            0.020            1.0
      11                2462         25.410            0.020            1.0




Report No: SA940629L08                        5


FCC ID: RD7-A5020




802.11a OFDM modulation
Antenna gain: 7dBi
                      Channel                                         Limit of
                                 Output Power to   Power Density
   Channel           Frequency                                     Power Density
                                  Antenna (mW)       (mW/cm2)
                       (MHz)                                         (mW/cm2)
       1                5180          8.279            0.008            1.0
       4                5240         14.421            0.014            1.0
       5                5260         13.366            0.013            1.0
       8                5320         13.152            0.013            1.0
       9                5745         31.769            0.032            1.0
      11                5785         31.989            0.032            1.0
      13                5820         32.137            0.032            1.0

Antenna gain: 2.27dBi
                      Channel                                         Limit of
                                 Output Power to   Power Density
   Channel           Frequency                                     Power Density
                                  Antenna (mW)       (mW/cm2)
                       (MHz)                                         (mW/cm2)
       1                5180          8.279            0.003            1.0
       4                5240         14.421            0.005            1.0
       5                5260         13.366            0.004            1.0
       8                5320         13.152            0.004            1.0
       9                5745         31.769            0.011            1.0
      11                5785         31.989            0.011            1.0
      13                5820         32.137            0.011            1.0

Antenna gain: 8dBi
                      Channel                                         Limit of
                                 Output Power to   Power Density
   Channel           Frequency                                     Power Density
                                  Antenna (mW)       (mW/cm2)
                       (MHz)                                         (mW/cm2)
       1                5180          8.279            0.010            1.0
       4                5240         14.421            0.018            1.0
       5                5260         13.366            0.017            1.0
       8                5320         13.152            0.017            1.0
       9                5745         31.769            0.040            1.0
      11                5785         31.989            0.040            1.0
      13                5820         32.137            0.040            1.0




Report No: SA940629L08                        6



Document Created: 2005-09-06 09:57:19
Document Modified: 2005-09-06 09:57:19

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