Wavecom EasySatSystem (W-PCIe, W-PCI) V1.1.00 - Manual (Page 6)

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Hardware WAVECOM EasySat System for W-PCI/e V1.1.00 User Manual
The configuration interface, i.e., the text file EasySATSystemWP.ini, stored in same predefined directory.
Hardware
The monitoring system consists of three main components:
 An antenna, including a low noise amplifier (LNA)
 A down converter
 One or more W-PCI or W-PCIe card(s) with decoder SAT options on host computers
These components are connected with coax cable. If more than one W-PCI or W-PCIe is to be fed from the
same source, a splitter must be used to correctly match the input impedance of the 70-MHz input (input
IF70#1a, Zo = 50 Ohm).
Antenna/LNA
The antenna system must have a figure of merit G/T > 0 dB/K. This can be easily achieved with a parabol-
ic dish with a diameter of at least 2 m and a low noise amplifier (LNA) with a noise figure smaller than 0.8
dB. The polarization of the L-Band signal is RHCP (Right-Hand Circular polarization), so if a parabolic re-
flector is used, the feed must pick up the mirrored left-hand (LHCP) component.
Tracking of the satellite for this diameter of the dish is not necessary, and if so desired the antenna can be
of a fixed type, which is installed and aligned to the satellite only once.
The power of Inmarsat spot beams allow antennas for terminals to be quite small, but for monitoring pur-
poses larger antennas are required in order to also capture neighboring spot beams.
WAVECOM recommends a dish of at least 2.4 m diameter.
Down Converter
The down converter is a commercially available product, converting L-band to 70 MHz IF with a bandwidth
of +/- 20 MHz.
Required SNR before decoder: >15 dB (20 dB recommended).
PC(s) with W-PCI/e Cards
These are state of the art computers, running under Microsoft Windows XP, Windows 7 or Server 2008
with the same number of PCI slots as the number of W-PCI or W-PCIe cards to be installed.
We recommend 4 cards per PC if cooling and power supply are appropriate.
Check our application note “AN-INMARSAT Setup”.