RF Exposure Info

FCC ID: KA22002060010-2

RF Exposure Info

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FCCID_374034

FCC ID: KA22002060010-2

RF EXPOSURE REPORT

REPORT NO.: RF921106R03
MODEL NO.: DWL-520 v.D2, WPC-B13

ACCORDING: FCC Guidelines for Human Exposure
IEEE C95.1

APPLICANT: D-LINK CORPORATION.

ADDRESS: NO.8, Li Hsing Rd VII, SCIENCE-BASED
INDUSTRIAL PARK, HSINCHU, 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: RF921106R03 1

FCC ID: KA22002060010-2

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: RF921106R03 2

FCC ID: KA22002060010-2

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 the product, under normal use condition, is at least 20cm away from the
body of the user. Warming statement for keeping 20cm separation distance and the
prohibition of operating next to a person has been printed on the user’s manual. So, this
product is classified as the Mobile Device.

Report No: RF921106R03 3

FCC ID: KA22002060010-2

6 Test Results

6.1 Antenna Gain
The maximum Gain measured in Fully Anechoic Chamber is 1.8dBi or 1.514(numeric).

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

Channel Limit of
Output Power to Power Density
Channel Frequency Power Density
Antenna (mW) (mW/cm2)
(MHz) (mW/cm2)
1 2412 20.417 0.006 1.0
6 2437 20.893 0.006 1.0
11 2462 20.417 0.006 1.0

Report No: RF921106R03 4

Document Created: 2003-11-14 15:33:50
Document Modified: 2003-11-14 15:33:50

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