R1400 MPE

FCC ID: 2APK5-R1400

RF Exposure Info

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FCCID_3902010

R1400 (AKA GS1000-04) MPE EXPORT STATEMENT . WARNING - THIS ITEM IS CONTROLLED BY THE U.S. GOVERNMENT. IT MAY NOT BE RESOLD, TRANSFERRED, OR OTHERWISE DISPOSED OF, TO ANY OTHER COUNTRY OR TO ANY PERSON, EITHER IN ITS ORIGINAL FORM OR AFTER BEING INCORPORATED INTO OTHER ITEMS, WITHOUT FIRST OBTAINING APPROVAL FROM THE U.S. GOVERNMENT OR AS OTHERWISE AUTHORIZED BY U.S. LAW AND REGULATIONS. ITAR: XI(d) PROPRIETARY INFORMATION This document contains information proprietary to SRC that shall not be disclosed outside the organization receiving the document, and shall not be . duplicated, used, or disclosed in whole or in part for any purpose other than to evaluate its content. © 2016 SRC

MPE Ranges Worst Case scenario (scenario 1): Staring mode, boresight, 10% duty cycle, maximum output power R1400 Worst Case MPE ranges • Controlled: ~9 meters • Uncontrolled: ~ 22 meters SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 1

Maximum permissible exposure (MPE). The rms and peak electric and magnetic field strength, their squares, or the plane—wave equivalent power densities associated with these fields to which a person may be exposed without harmful effect and with an acceptable safety factor. Occupational/controlled exposure. For FCC purposes, applies to human exposure to RF fields when persons are exposed as a consequence of their employment and in which those persons who are exposed have been made fully aware of the potential for exposure and can exercise control over their exposure. Occupational/controlled exposure limits also apply where exposure is of a transient nature as a result of incidental passage through a location where exposure levels may be above general population/uncontrolled limits (see definition above), as long as the exposed person has been made fully aware of the potential for exposure and can exercise control over his or her exposure by leaving the area or by some other appropriate means. General population/uncontrolled exposure. For FCC purposes, applies to human exposure to RF fields when the general public is exposed or in which persons who are exposed as a consequence of their employment may not be made fully aware of the potential for exposure or cannot exercise control over their exposure. Therefore, members of the general public always fall under this category when exposure is not employment—related. _S)?l Defense » Environment » Intelligence

Table 1. LIMITS FOR MAXIMUM PERMISSIBLE EXPOSURE (MPE) (A) Limits for Occupational/Controlled Exposure Frequency Electric Field Magnetic Field Power Density Averaging Time Range Strength (E) Strength (H) (8) [E]*. [H] or S (MHz) (V/m) (A‘m) (mW/em‘) (minutes) 0.3—3.0 614 1.63 (100)* 6 3.0—30 1842/% 4.89/f (900/2)* 6 30—300 61.4 0.163 1.0 6 300—1500 —— —— £300 6 (B) Limits for General Population/Uncontrolled Exposure Frequency Electric Field Magnetic Field Power Density Averaging Time Range Strength (E) Strength (H) (8) [E]*. [H] or S (MHz) (V/m) (A‘m) (mW/em‘) (minutes) 0.3—1.34 614 1.63 (100)* 30 1.34—30 s24/f 219/f (180/82)* 30 30—300 27.5 0.073 0.2 30 £= frequency in MHz *Plane—wave equivalent power density

Other Standards MPE Limits Occupational General Public (Controlled) (Uncontrolled) [mW/cm2] [mW/cm2] FCC OET Bulletin 65 5 1 IEEE IEEE Std C95.1 10 1 Canada Safety Code 6 5 1 International ICNIRP Guidelines 5 1 Since FCC OET 65 is widely accepted and the minimum of all standards, these will be used for the analysis SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 4

OET Bulletin 65 Equations OET Bulletin 65 has equations on pages 26-30 that apply to aperture antennas. These equations should provide coarse, conservative power estimates, even for a phase array. Simulation techniques (closed form expressions or WIPL) should provided better results in the antenna near field. The OET 65 equations and simulation should be equivalent in the far-field SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 5

Antenna Surface. The maximum power density directly in front of an antenna (e.g., at the antenna surface) can be approximated by the following equation: Near—Field Region. In the near—field. or Fresnel region. ofthe main beam., the power density can reach a maximum before it begins to decrease with distance. The extent ofthe near—field can be described by the following equation (D and A in same units): 2° 41 (12)

Pae ~ ~~~z (13) P=power fed to the antenna Aperture efficiency can be estimated. or a reasonable approximation for circular apertures can be obtained from the ratio of the effective aperture area to the physical area as follows: ca?) in ( nu’] (14) 4 where: n = aperture efficiency for circular G= power gain in the direction ofinterest relative to an isotropic radiator ) =wavelength D= antenna diameter If the antenna gain is not known, it can be calculated from the following equation using the actual or estimated value for aperture efficiency: c 42m S (15) where: n = aperture efficiency G= power gain in the direction ofinterest relative to an isotropic radiator ) =wavelength A=physical area ofthe antenna

Transition Region. Power density in the transition region decreases inversely with distance from the antenna, while power density in the far—field (Fraunhofer region) of the anterna decreases inversely with the sqirare ofthe distance. For purposes ofevaluating RF exposure, the distance to the beginning ofthe far—field region (farthest extent ofthe transition region) can be &6 A (16) Equation (12), to Rg. If the location of interest falls within this transition region. the on—axis * a (17) where: 5, =power density in the transition region 5,, = maximum power density for near—field calculated above R.,= extent of near—field calculated above R. = distance to point ofinterest Far—Field Region. The power density in the far—field or Fraunhofer region ofthe antenna pattem decreases inversely as the square ofthe distance. The power density in the far—field region ofthe Ere = ro axR" (18) where: S, =power density (on axis) P= power fed to the antenna G= power gain ofthe antenma in the direction ofinterest relative to an isotropic radiator R. = distance to the point ofinterest

Transmit Power Variables Several variables can affect the transmitted power The transmitted power from the OET65 equation 18 is an average power. Some, but not all, factors affecting the total output power: • Duty cycle of a pulsed signal • Scan rate of an antenna • Number of elements in an array • Antenna efficiency • Transmit amplifier peak power and post amplifier losses • Antenna pattern and desired location in that antenna pattern (ie. boresight) SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 9

WIPL Simulation WIPL-D is an electromagnetic simulation tool that uses Method of Moments techniques to predict the performance of antenna structures The tool can be used to predict the power density of a phased array antenna at various ranges To get the proper power density, the output of WIPL-D must be scaled by the proper element power with respect to the generator voltages and impedances used in the model SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 10

WIPL-D Results vs. OET65 Prediction Assumptions: • 4W peak amplifier power • 2dB loss post amplifier • 256 total elements (8x32 array) • Duty Cycle: 10% • Located at boresight of antenna Red Line: OET 65 Equations Blue Line: WIPL-D simulation Note: OET and sim are close in the far-field Estimated MPE ranges: – Uncontrolled: 19.2m – Conctrolled: 9.1m SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 11

Power Density Closed Form Expression • Reference: “Analysis of Power Density Levels For Raytheon Prototype Radar Demonstration System (PRDS)” • See Appendix for derivation of this with assumptions SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 12

Closed Form Expression vs. OET65 Prediction: Scenario 1 Assumption: • 4W peak amplifier power – Scanrate: 0Hz, staring mode – Element pattern: Raised Cosine • 2dB loss post amplifier – Element gain: 5.7dBi – Az Beamwidth: λ/(Aperture Size) • 256 total elements (8x32 array) – Antenna efficiency: 100% • Duty Cycle: 10% – Raised cosine exponent: 1 • Boresight – Frequency: 9.8GHz SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 13

Closed Form Expression vs. OET65 Prediction: Scenario 2 Assumption: Changes from Scenario 1 highlighted in red • 4W peak amplifier power – Scanrate: 0Hz, staring mode – Element pattern: Raised Cosine • 2dB loss post amplifier – Element gain: 5.7dBi – Az Beamwidth: λ/(Aperture Size) • 256 total elements (8x32 array) – Antenna efficiency: 100% • Duty Cycle: 5% – Raised cosine exponent: 1 • Boresight – Frequency: 9.8GHz SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 14

Closed Form Expression vs. OET65 Prediction: Scenario 3 Assumption: Changes from Scenario 1 highlighted in red • 4W peak amplifier power – Scanrate: 0.25Hz, rotating mode – Element pattern: Raised Cosine • 2dB loss post amplifier – Element gain: 5.7dBi – Az Beamwidth: λ/(Aperture Size) • 256 total elements (8x32 array) – Antenna efficiency: 100% • Duty Cycle: 5% – Raised cosine exponent: 1 • Boresight – Frequency: 9.8GHz SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 15

Closed Form Expression vs. OET65 Prediction: Scenario 4 Assumption: Changes from Scenario 1 highlighted in red • 4W peak amplifier power – Scanrate: 1Hz, rotating mode – Element pattern: Raised Cosine • 2dB loss post amplifier – Element gain: 5.7dBi – Az Beamwidth: λ/(Aperture Size) • 256 total elements (8x32 array) – Antenna efficiency: 100% • Duty Cycle: 5% – Raised cosine exponent: 1 • Boresight – Frequency: 9.8GHz SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 16

Analysis Findings Summary OET65, WIPL-D, closed form expressions are very close in the far-field of an antenna Closed form expressions can be used in absence of MoM simulation with more assumptions WIPL-D is the best prediction of radiating near-field performance. SRC, Inc. Proprietary/EXPORT CONTROLLED DATA 17


Document Created: 2018-06-06 10:02:02
Document Modified: 2018-06-06 10:02:02
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