Exhibit B

0047-EX-ML-2003 Text Documents

ViaSat, Inc.

2003-07-28

             EXHIBIT B




RADIATION HAZARD ANALYSIS AND REPORT


This exhibit contains a report of the analysis of the radio frequency (RF) hazard present
during the operation of the proposed radio and antenna system.

The test hub facility will utilize a SeaTel Model 4003 1.0 m earth station antenna and a 4
watt power amplifier.

Note that while for the purposes of this radiation hazard analysis the full 4 watt power
output of the transmitter has been considered, when transmitting, the 1.0 m antenna will
operate in a burst mode with a duty cycle typically less than 10%.


Analysis of Non-Ionizing Radiation for a 1.0 m Earth Station System

This report analyzes the non-ionizing radiation levels for a 1.0 m earth station system.
The analysis and calculations performed in this report are in compliance with the
methods described in the FCC Office of Engineering and Technology Bulletin No. 65.

Bulletin No. 65 specifies that there are two separate tiers of exposure limits that are
dependant upon the situation in which the exposure takes place and/or the status of the
individuals who are subject to the exposure. The two tiers are General Population /
Uncontrolled environment, and an Occupational / Controlled environment.

The applicable exposure limit for the General Population / Uncontrolled environment at
this frequency of operation is 1 mW/cm^2.

The applicable exposure limit for the Occupational / Controlled environment at this
frequency of operation is 5 mW/cm^2.

Definition of terms

The terms are used in the formulas here are defined as follows:

Ssurface = maximum power density at the antenna surface
Snf = maximum near-field power density
St = power density in the transition region
Sff = power density (on axis)
Rnf = extent of near-field
Rff = distance to the beginning of the far-field
R = distance to point of interest
P=4W                           power fed to the antenna in Watts
A = 0.785 m2                   physical area of the aperture antenna
                 4
G = 1.4494 x 10                power gain relative to an isotropic radiator
D = 1.0 m                      diameter of antenna in meters
F = 14,250                     frequency in MHz
λ = 0.021 m                    wavelength in meters (300/FMHz)
η = 0.65                       aperture efficiency


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:

Ssurface = (4 * P) / A

        = (4 * 4) / 0.785 m2

        = 20.372 W/m2

        = 2.037 mW/cm2


Near Field Region. In the near-field or Fresnel region, of the main beam, the power
density can reach a maximum before it begins to decrease with distance. The extent of
the near field can be described by the following equation (D and λ in same units):

Rnf     = D2 / (4 * λ)

        = 1.02 / (4 * 0.021)

        = 11.883 m


The magnitude of the on-axis (main beam) power density varies according to location in
the near field. However, the maximum value of the near-field, on-axis, power density
can be expressed by the following equation:

Snf     = (16 * η * P) / (π * D2)

        = (16 * 0.65 * 4) / (π * 1.02)

        = 13.242 W/m2

        = 1.324 mW/cm2


Far-Field Region. The power density in the far-field or Fraunhofer region of the
antenna pattern decreases inversely as the square of the distance. The distance to the start
of the far field can be calculated by the following equation:

Rff     = (0.6 * D2) / λ

        = (0.6 * 1.02) / 0.021

        = 28.52 m


The power density at the start of the far-field region of the radiation pattern can be
estimated by the equation:

Sff    = (P * G) / (4 * π * Rff2)

       = (4 * 1.4494 x 104) / (4 * π * 28.522)

       = 5.672 W/m2

       = 0.567 mW/cm2


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
antenna decreases inversely with the square of the distance. The transition region will
then be the region extending from Rnf to Rff. If the location of interest falls within this
transition region, the on-axis power density can be determined from the following
equation:

St     = (Snf * Rnf) / R

       = (1.324 * 11.883) / R

       = (15.735 m * mW/cm2) / R              where R is the location of interest in meters


Summary of expected radiation levels for an Uncontrolled environment


Region                        Maximum Power Density                Hazard Assessment

Far field (Rff) = 28.52 m            0.567 mW/cm2                  Satisfies FCC MPE

Near field (Rnf) = 11.883 m          1.324 mW/cm2                  Potential Hazard

Transition region (Rt)
(Rt) = Rnf < Rt < Rff                1.324 mW/cm2                  Potential Hazard

Main Reflector Surface (Ssurface)    2.037 mW/cm2                  Potential Hazard



Summary of expected radiation levels for a Controlled environment


Region                        Maximum Power Density                Hazard Assessment

Far field (Rff) = 28.52 m            0.567 mW/cm2                  Satisfies FCC MPE

Near field (Rnf) = 11.883 m          1.324 mW/cm2                  Satisfies FCC MPE

Transition region (Rt)
(Rt) = Rnf < Rt < Rff                1.324 mW/cm2                  Satisfies FCC MPE

Main Reflector Surface (Ssurface)    2.037 mW/cm2                  Satisfies FCC MPE



Conclusions

The antenna will be mounted in a shipboard location in an area above normal foot traffic
and only accessible by authorized maintenance personal. Based on the above analysis it
is concluded that harmful radiation levels will not exist in regions normally occupied by
the public.



Document Created: 2003-07-28 18:12:01
Document Modified: 2003-07-28 18:12:01

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