RF Info

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RF Exposure Info

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                                      RF Exposure evaluation

Exposure category: General population/uncontrolled environment
EUT Type: Production Unit
Device Type: Mobile Device
Refer Standard: KDB 447498 D01 General RF Exposure Guidance v06
        FCC Part 2 §2.1091

FCC ID: 2AT6H-GM-02

1. Applicable Standard
According to §1.1307(b)(1), 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 level in excess of the
Commission’s guidelines.
According to §1.1310 and §2.1093 RF exposure requirement
KDB447498 v06: Mobile and Portable Devices RF Exposure Procedures and Equipment Authorization
Policies.

2. Requirement
According to KDB447498 D01 General RF Exposure Guidance v06 Section 4.3.1 Standalone SAR test
exclusion considerations: “Unless specifically required by the published RF exposure KDB procedures,
standalone 1-g head or body and 10-g extremity SAR evaluation for general population exposure conditions,
by measurement or numerical simulation, is not required when the corresponding SAR Test Exclusion
Threshold condition, listed below, is satisfied. These test exclusion conditions are based on source-based
time-averaged maximum conducted output power of the RF channel requiring evaluation, adjusted for tune-up
tolerance, and the minimum test separation distance required for the exposure conditions.22 The minimum
test separation distance is determined by the smallest distance from the antenna and radiating structures or
outer surface of the device, according to the host form factor, exposure conditions and platform requirements,
to any part of the body or extremity of a user or bystander (see 5) of section 4.1). To qualify for SAR test
exclusion, the test separation distances applied must be fully explained and justified by the operating
configurations and exposure conditions of the transmitter and applicable host platform requirements, typically
in the SAR measurement or SAR analysis report, according to the required published RF exposure KDB
procedures. When no other RF exposure testing or reporting is required, a statement of justification and
compliance must be included in the equipment approval, in lieu of the SAR report, to qualify for the SAR test
exclusion. When required, the device specific conditions described in the other published RF exposure KDB
procedures must be satisfied before applying these SAR test exclusion provisions; for example, handheld PTT
two-way radios, handsets, laptops & tablets etc.23 “
[(max. power of channel, including tune-up tolerance, mW)/ (min. test separation distance, mm)] · [√f (GHz)]
≤ 3.0 for 1-g SAR and ≤ 7.5 for 10-g extremity SAR, where:
• f (GHz) is the RF channel transmit frequency in GHz
• Power and distance are rounded to the nearest mW and mm before calculation
• The result is rounded to one decimal place for comparison
• 3.0 and 7.5 are referred to as the numeric thresholds in the step 2 below
The test exclusions are applicable only when the minimum test separation distance is ≤ 50 mm and for
transmission frequencies between 100 MHz and 6 GHz. When the minimum test separation distance is < 5
mm, a distance of 5 mm according to 5) in section 4.1 is applied to determine SAR test exclusion.


3. Limit
Limits for Maximum Permissible Exposure (MPE)/Controlled Exposure
                                                                               Averaging
  Frequency        Electric Field      Magnetic Field    Power Density
                                                                                 Time
 Range(MHz)        Strength(V/m)       Strength(A/m)       (mW/cm²)
                                                                                (minute)
                   Limits for Occupational/Controlled Exposure
   0.3 – 3.0
                     614               1.63             (100) *                    6
   3.0 – 30
                    1842/f            4.89/f           (900/f2)*                   6
   30 – 300
                     61.4             0.163               1.0                      6
  300 – 1500
                       /                 /               f/300                     6
    1500 –
                       /                 /                 5                       6
   100,000
Limits for Maximum Permissible Exposure (MPE)/Uncontrolled Exposure
                                                                               Averaging
  Frequency        Electric Field      Magnetic Field    Power Density
                                                                                 Time
 Range(MHz)        Strength(V/m)       Strength(A/m)       (mW/cm²)
                                                                                (minute)
                      Limits for Occupational/Controlled Exposure
      0.3 – 3.0
                        614                 1.63              (100) *              30
      3.0 – 30
                        824/f              2.19/f            (180/f2)*             30
      30 – 300
                        27.5               0.073                0.2                30
     300 – 1500
                          /                   /               f/1500               30
       1500 –
                          /                   /                 1.0                30
      100,000

F=frequency in MHz
*=Plane-wave equivalent power density

4. MPE Calculation Method
Predication of MPE limit at a given distance
Equation from page 18 of OET Bulletin 65, Edition 97-01

S=PG/4πR²
Where: S=power density
     P=power input to antenna
     G=power gain of the antenna in the direction of interest relative to an isotropic radiator
     R=distance to the center of radiation of the antenna
As declared by the Applicant, the EUT transmits with the maximum soure-baed Duty Cycle of 100%-see the
User manual, and the EUT is a wireless device used in a mobile application, at least 20 cm from any body part
of the user or nearby persons; from the maximum EUT RF output power, the minimum mobile separation
distance, r =20cm, as well as the gain of the used antenna is 4dBi for WLAN, and the power drift from Turn-
up Procedure provide by manufacturer as following states, the RF power density can be obtained.

5.     Antenna Information
use antennas certificated as follows provided by manufacturer;
                                              Antenna type
   Internal       Antenna Identification                           Operate frequency          Maximum
                                              and antenna
 Identification     in Internal photos                                   band                antenna gain
                                                number
      Antenna        2.4G Wifi Chain          FPC Antenna        2.4GHz – 2.4835 GHz             4dBi


6. Evaluation Results for Standalone
6.1 Standalone MPE
As declared by the Applicant, the EUT is a wireless device used in a fix application, at least 20 cm from
any body part of the user or nearby persons; from the maximum EUT RF output power, the minimum
separation distance, r =20cm, as well as the gain of the used antenna refer to antenna information, the
RF power density can be obtained.



                               Max                       Antenna
                  Target                 Max Output
                             tune up                      Gain      Power Density
 Modulation     power W/                  power to                                      Limit
                              power                     (Numeric)    at R=20cm                     Result
   Type         tolerance                 antenna                                     (mW/cm2)
                             toleranc                                (mW/cm2)
                  (dBm)                    (mW)
                              e(dBm)
   802.11b       16±1.0         17         50.119           4          0.02505           1.0       Pass

   802.11g       16±1.0         17         50.119           4          0.02505           1.0       Pass
   802.11n
                 15±1.0         16         39.811           4          0.01989           1.0       Pass
   (HT20)


7. Conclusion
The measurement results comply with the FCC Limit per 47 CFR 2.1091 for the uncontrolled RF
Exposure of mobile device.



Document Created: 2019-08-06 19:47:08
Document Modified: 2019-08-06 19:47:08

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