RF Exposure Info

FCC ID: S9ZTEW432BRP

RF Exposure Info

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FCCID_682540

FCC ID: S9ZTEW432BRP

RF EXPOSURE REPORT

REPORT NO.: SA931018L03E
MODEL NO.: TEW-432BRP

ACCORDING: FCC Guidelines for Human Exposure
IEEE C95.1

APPLICANT: TRENDware International Inc.

ADDRESS: 3135 Kashiwa Street, Torrance, CA 90505
United States

ISSUED BY: Advance Data Technology Corporation

TEST LOCATION: 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., Kueishan, Taoyuan,
Taiwan, R.O.C.

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Report No: SA931018L03E

FCC ID: S9ZTEW432BRP

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

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Report No: SA931018L03E

FCC ID: S9ZTEW432BRP

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. Warning 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.

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Report No: SA931018L03E

FCC ID: S9ZTEW432BRP

6 Test Results

6.1 Antenna Gain

The maximum Gain measured in Fully Anechoic Chamber is 2dBi 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 56.234 0.018 1.0
6 2437 56.494 0.018 1.0
11 2462 56.364 0.018 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 40.738 0.013 1.0
6 2437 39.811 0.013 1.0
11 2462 35.481 0.011 1.0

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Report No: SA931018L03E

Document Created: 2006-07-18 07:49:07
Document Modified: 2006-07-18 07:49:07

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