MPE Estimates 1

FCC ID: KBCIX-MC8775

RF Exposure Info

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FCCID_798872

Applicant: General Dynamics Itronix Corporation FCC ID: KBCIX-MC8775 Compliance with 47 CFR 15.247(i) “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). Calculations are provided for each radio transmitting through its own internal antenna and optional external antenna. The total transmit power is less than 1.5 W (ERP), 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. 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 tables on the following pages: 1

Applicant: General Dynamics Itronix Corporation FCC ID: KBCIX-MC8775 MPE Estimates for Self Located Device FCC ID: KBCIX-MC8775 In the IX605 Host PC GSM, GPRS, EDGE, UMTS, WCDMA, HSDPA Source- based time Ratio of General averaging Power Max Peak Max Power Population Transmit corrected Density to Antenna Type Antenna Part No. EIRP ERP Density @ Exposure Frequency Power the Output Output 20 cm Limit from Density @ Exposure 1.1310 20 cm Limit IX605 Primary 2 WAN (MHz) (mW) (mW) (mW/cm ) (mW/cm2) (mW/cm2) Meander Line Skycross 2-2920 848.8 3872.04 2361 0.770 0.1925 0.56 0.340 Meander Line Skycross 2-2920 1850.2 1589.0 0.316 0.079 1 0.079 Worst Case Ratio of Power Density to the Exposure Limit = 0.340 Source-based time averaging corrected for the GPRS Duty Cycle of 25% “worst case”. 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 ratio(s) (power density to the exposure limit) does not exceed 1.0; therefore, the exposure condition is compliant with FCC rules. 2

Applicant: General Dynamics Itronix Corporation FCC ID: KBCIX-MC8775 MPE Estimates for Self Located Device FCC ID: KBCIX-4965AGN WLAN, IEEE 802.11 (a) (b) (g) & (n) Ratio of General Max Peak Minimum Power Power Antenna Antenna Part Transmit Antenna Population Conducted Antenna Density @ Density to the Type No. Frequency Gain Exposure Limit Output Power Cable Loss 20 cm Exposure from 1.1310 Limit 2 2 (MHz) (mW) (dBi) (dB) (mW/cm ) (mW/cm ) Part 15C Inverted F MAIN EST07-10 5745-5825 303 -2.0 2.0 0.024 1 0.024 Inverted F MAIN EST07-10 2412-2462 463 -3.5 0.9 0.033 1 0.033 External MaxRad MAXC24503 2412-2462 463 3 4.4 0.067 1 0.067 External MaxRad BMAXC24505 2412-2462 463 5 4.4 0.106 1 0.106 Part 15 E Inverted F MAIN EST07-10 5180-5240 50 -2.0 2.0 0.004 1 0.004 Inverted F MAIN EST07-10 5260-5320 123 -2.0 2.0 0.010 1 0.010 Worst Case Ratio of Power Density to the Exposure Limit = 0.106 Worst Case Co-located Exposure Condition FCC ID: KBCIX-MC8775 FCC ID: KBCIX-4965AGN Per Note 24 shown below, the Sum of Worst Case Power Ratios cannot exceed 1.0 * Note: GPRS 25% Duty Cycle “worst case” was taken in to account for GSM radio. 802.11abgn Sum of Worst GSM Radio Radio Worst Case Ratios Worst Case FCC Limit for Case Ratio of (Power Ratio of Power Sum of Worst Power Density Density to the Density to the Case Ratios to the Exposure Exposure Exposure Limit Limit Limit) 0.340 0.106 0.446 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 accounts for transmitters operating at different frequencies against different exposure limits. 3


Document Created: 2007-05-31 09:51:11
Document Modified: 2007-05-31 09:51:11
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