RF Exposure Info

FCC ID: K7SF7D1401V1

RF Exposure Info

Download: PDF
FCCID_1241550

                      RF EXPOSURE REPORT

                REPORT NO.:    SA981204H03A

                 MODEL NO.:    F7D1401 v1



                ACCORDING:     FCC Guidelines for Human Exposure
                               IEEE C95.1


                 APPLICANT:    Belkin International, Inc.

                   ADDRESS:    501 West Walnut Street, Compton, CA 90220-5221,
                               USA




                  ISSUED BY:   Bureau Veritas Consumer Products Services (H.K.)
                               Ltd., Taoyuan Branch
             LAB LOCATION:     No. 81-1, Lu Liao Keng, 9th Ling, Wu Lung Tsuen,
                               Chiung Lin Hsiang, Hsin Chu Hsien 307, Taiwan.




                                            1
Report No.: SA981204H03A                                     Report Format Version 3.0.1
Reference No.:981216H01


                           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 our lab, 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                  30
 1500-100,000               …               …                 1.0                   30
F = Frequency in MHz




                                              2
Report No.: SA981204H03A                                            Report Format Version 3.0.1
Reference No.:981216H01


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




                                              3
Report No.: SA981204H03A                                        Report Format Version 3.0.1
Reference No.:981216H01


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:
                   Channel                                           Limit of
                              Output Power to   Power Density
   Channel        Frequency                                       Power Density
                              Antenna (mW)        (mW/cm2)
                    (MHz)                                           (mW/cm2)
      1              2412          93.3            0.029               1.0
      6              2437          93.3            0.029               1.0
      11             2462          81.3            0.026               1.0

 802.11g:
                   Channel                                           Limit of
                              Output Power to   Power Density
   Channel        Frequency                                       Power Density
                              Antenna (mW)        (mW/cm2)
                    (MHz)                                           (mW/cm2)
      1              2412         380.2            0.120               1.0
      6              2437         389.0            0.123               1.0
      11             2462         363.1            0.114               1.0

 802.11n (20MHz):
                   Channel                                           Limit of
                              Output Power to   Power Density
   Channel        Frequency                                       Power Density
                              Antenna (mW)        (mW/cm2)
                    (MHz)                                           (mW/cm2)
      1              2412         323.6            0.102               1.0
      6              2437         407.4            0.128               1.0
      11             2462         371.5            0.117               1.0

 802.11n (40MHz):
                   Channel                                           Limit of
                              Output Power to   Power Density
   Channel        Frequency                                       Power Density
                              Antenna (mW)        (mW/cm2)
                    (MHz)                                           (mW/cm2)
       1             2422         263.0            0.083               1.0
       4             2437         346.7            0.109               1.0
       7             2452         263.0            0.083               1.0




                                          4
Report No.: SA981204H03A                                   Report Format Version 3.0.1
Reference No.:981216H01



Document Created: 2010-02-11 17:40:49
Document Modified: 2010-02-11 17:40:49

© 2025 FCC.report
This site is not affiliated with or endorsed by the FCC