INSTALLATION
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3-7
COM-00-21-05 OCTOBER 2021
Version No.: A
3.7.4 GPS Antenna
The optional antenna recommended for use with the Airlink Mars is a Trimble Bullet III GPS
antenna (or equivalent) as shown below. This antenna requires 5 VDC which is supplied
through the Airlink Mars GPS connector.
The Trimble antenna has a TNC female connector. The cable from the Airlink Mars should be a
single run TNC-male to SMA-male RG-8X cable (without additional connectors or adapters) and
no longer than 75 feet as the antenna is an active 5 VDC device with power supplied over this
interface. Lower loss cable such as RG-8 can be used for extended length if needed.
The antenna should be installed with a clear view of the sky. The base of the unit is threaded to
allow it to be mounted on a hollow conduit.
Feature
3.3V
5.0V
Prime Power
3.3V DV (±10%)
5.0V DV (±10%)
Power Consumption
<20mA
<30mA
Gain
28dB ± 3dB
30dB ± 3dB
Output Impedance
50Ω
Frequency
GPS L1 1575.42 ±1.023MHz
VSWR
2.0 maximum
Axial ratio
90°: 4dB maximum;
10°: 6 dB maximum
Noise
3.0dB (typical)
Bandwidth (10dB RL)
50MHz (min)
Out of Band rejection
fo=1575.42MHz
fo ±20 MHz: 7dB min
fo ±30 MHz: 12dB min fo
±50 MHz: 20 dB min fo
±100MHz: 30dB min
Azimuth coverage
360° (omnidirectional)
Elevation coverage
0°-90° elevation
(hemispherical)
0°-90° elevation
(hemispherical)
ESD
IEC 61000-4-2
Figure 3-6 Trimble Bullet III GPS Antenna
NOTE
RF cabling should be installed by properly trained and qualified
personnel.