User Guide to ST8050
ST8050UG001 – User Guide
17
Revision 2.0
3
Antenna setup
3.1
Antenna recommendations
3.1.1
GPS
The GPS antenna should be 3.3 VDC active. The recommended active antenna gain should be in the
range of 17dB to 42 dB in the Low Noise Amplifier (LNA). Ensure that the GPS antenna is located
where it has an unobstructed view of the sky. Active antennas are usually low-profile patch types.
3.1.2
Iridium
Iridium antennas must be approved by Iridium before being used on the Iridium network. A list of
approved antennas can be found on Iridium’s home page at
www.iridium.com
.
When selecting an Iridium antenna, make sure it is 50 ohm, Gain 3dBi maximum, polarization Right
Hand Circular Polarized (RHCP) and VSWR 1.5:1 or better (in both receive and transmit bands) for
optimal messaging. Make sure that the Iridium antenna is located where it has an unobstructed
view of the sky.
There cannot be more than a 3 dB loss between the antenna and the modem.
The antenna must be placed greater than 20cm from a person. If antenna is placed within 20cm of a
person, the system integrator needs to assess the final product against SAR regulation.
3.1.3
GSM/GPRS
The GSM/GPRS antenna does not require an unobstructed view of the sky. However, for optimal
performance, an unobstructed view is preferable.
GSM antenna requirements
Gain must be less than 3dBi.
Must be placed greater than 20cm from a person. If antenna is placed within 20cm of a person,
the system integrator needs to assess the final product against SAR regulation.
If the antenna is co-located and transmitting simultaneously with another antenna, additional
FCC/IC testing may be required.
Antenna cannot be placed within a metal shield and must be installed with care to avoid any
interference with other electronic devices.
3.2
Grounding
Grounding may be done in several ways:
Fixed Site: Grounding Rods should be connected to the antenna shield. Keep grounding
systems as short as possible.
Mobile: Chassis Ground should be connected to the negative side of the battery. Make sure
all connections are corrosion free.
Marine Grounding Systems: Skilled marine electricians should be consulted when adding an
ORBCOMM solution.
