Module Report

FCC ID: HN2ABTM3-3

RF Exposure Info

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FCCID_381341

Exhibit H: RF Exposure

FCC ID: HN22011B

Compliance with 47 CFR 15.247(b)(5)
“Systems operating under the provisions of this section shall be operated in a manner that ensures
that the public is not exposed to radio frequency energy levels in excess of the Commission's
guidelines. See § 1.1307(b)(1) of this chapter.”

The EUT will only be used with a separation distance of 20 centimeters or greater between the antenna and the body of the user or
nearby persons and can therefore be considered a mobile transmitter per 47 CFR 2.1091 (b). No radiating structure will be within
2.5cm of the user’s hands or wrists. The EUT will only be used in the applicant’s Model 700C Hand-held Terminal. There are no
provisions for body worn configurations. The 700C can be configured with the EUT and a Bluetooth radio (FCC ID: HN2ABTM3-
2).

The maximum peak power was measured to be 73.2 mW (ERP) for FCC ID: HN2011B, and 0.61 mW (ERP) for FCC ID:
HN2ABTM3-2. The transmit frequency is greater than 1.5 GHz, therefore the EUT is categorically excluded from routine
environmental evaluation per 47 CFR 2.1091(c).

The MPE estimates are as follows:

Table 1 in 47 CFR 1.1310 defines the maximum permissible exposure (MPE) for the general population as 1mW/cm2. The exposure
level at a 20 cm distance from the EUT’s transmitting antenna is calculated using the general equation:

S = (PG)/4πR2
Where: S = power density (mW/cm2)
P = power input to the antenna (mW)
G = numeric power gain relative to an isotropic radiator
R = distance to the center of the radiation of the antenna (20 cm = limit for MPE estimates)
PG = EIRP

Solving for S, the maximum power densities 20 cm from the transmitting antennas are summarized in the following tables:

MPE Estimates for Self Co-located Device

FCC ID: HN2011B

802.11 (b) Radio

Ratio of
General
Power
Max Peak Minimum Power Population
Antenna Part Transmit Antenna Density to
Antenna Type Conducted Antenna Density @ Exposure
No. Frequency Gain the
Output Power Cable Loss 20 cm Limit from
Exposure
1.1310
Limit
2 2
(MHz) (mW) (dBi) (dB) (mW/cm ) (mW/cm )

External tuned dipole 805-606 2400 89 1.3 0 0.024 1 0.024
Internal folded monopole 805-608 2400 89 -2 0 0.011 1 0.011

Worst Case Ratio of Power Density to the Exposure Limit = 0.024 ( External Tuned Dipole Antenna)

FCC ID: HN2ABTM3-2

Bluetooth Radio

Ratio of
General
Max Peak Minimum Power
Power Population
Transmit Conducted Antenna Antenna Density
Antenna Type Antenna Part No. Density Exposure
Frequency Output Gain Cable to the
@ 20 cm Limit from
Power Loss Exposure
1.1310
Limit
2 2
(MHz) (mW) (dBi) (dB) (mW/cm ) (mW/cm )
Internal Integral Antenna ABTM3 2400 3.78 -5.77 0 0.00020 1 0.00020

Worst Case Ratio of Power Density to the Exposure Limit = 0.00020 (Internal Integral Antenna)

Exposure Scenarios for 700C

Per Note 24 shown below (taken from FCC slides), the Sum of Worst Case Power Ratios cannot exceed 1.0

Sum of
Worst Case
802.11b Radio Bluetooth Radio Ratios FCC Limit
Worst Case Ratio of Power Worst Case Ratio of Power Density (Power for Sum of
Density to the Exposure Limit to the Exposure Limit Density to Worst Case
(FCC ID: HN2011B) (FCC ID: HN2ABTM3-2) the Ratios
Exposure
Limit)
0.02400 0.00020 0.02420 1.0 PASS
no radio 0.00020 0.00020 1.0 PASS
0.02400 no radio 0.02400 1.0 PASS

The results shown in the above table are equivalent to the Sum of the EIRP of the Two Co-located Transmitters (EIRP
TX1 + EIRP TX2) compared to the exposure limit. The benefit of this method, is that it accounts for transmitters operating
at different frequencies against different exposure limits.

Please note that EIRP = ERP x 1.64, so EIRP is worst case. However, because some parties would prefer to see the
calculation as the Sum of the ERP of the Two Co-located Transmitters, the table below shows compliance with ERP TX1
+ ERP TX2

General
802.11b Radio Bluetooth Radio Sum of Power Population
(FCC ID: HN2011B) (FCC ID: HN2ABTM3-2) Worst Case Density @ Exposure
Worst Case ERP Worst Case ERP ERPs 20 cm Limit from
1.1310

2 2
(mW) (mW) (mW) (mW/cm ) (mW/cm )
73.21 0.61 73.82 0.01469 1.0 PASS
no radio 0.61 0.61 0.00012 1.0 PASS
73.21 no radio 73.21 0.01456 1.0 PASS

Excerpts from TCB Training, April 3, 2002, “Mobile Transmitters”, Slide 6:

“Devices operating in multiple frequency bands

When RF exposure evaluation is required for TCB approval
o Separate antennas – estimated minimum separation distances may be considered for the frequency bands
that do not require evaluation or TCB approval, however, the estimated distance should take into account
the effect of co-located transmitters. (Note 24)

Note 24 According to multiple frequency exposure criteria, the ratio of field strength or power density to
the applicable exposure limit at the exposure location should be determined for each transmitter and the
sum of these ratios must not exceed 1.0 for the location to be compliant.”

The sum of the worst-case power ratios in any scenario does not exceed 1.0 (see Note 24 above); therefore, the exposure condition is
compliant with FCC rules.

Document Created: 2003-05-02 10:42:59
Document Modified: 2003-05-02 10:42:59

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