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Iridium Communications Inc.
9602 SBD Transceiver Product Developers Guide
Revision 5`
4.2.1 Antenna Characteristics
The 9602/9602N should be connected to an Iridium-band antenna with the following antenna connector
characteristics as described in Table 11.
Note:
•
Existing qualified Iridium antennas may be used. (i.e. antennas designed for the 9601, 9522, 9522A and
9522B)
•
Existing antennas will require different RF connector types to than those for the 9601, 9522, 9522A and
9522B
4.3 GPS Connector
The second RF connector, labeled "GPS" in the board silkscreen, is a pass-through connection from the
antenna path and is provided for GPS receivers that wish to share the main antenna. An overview of this
circuit is provided in Figure 7. The following operational points should be noted when using GPS receivers
connected to this point.
The GPS pass-through path is activated by detecting the presence of a DC voltage on the center-pin of
o
the GPS connector. The 9602/9602N uses the voltage from the GPS center pin to switch on the RX
path and requires minimal current (<100uA). The GPS path activated when this center-pin voltage is
higher than 1.2V (9602) / 1.6V (9602N).
There is a gain of approximately -3dB (9602) / +5.0dB (9602N) in the receive direction from ANT to
o
GPS.
The GPS receive path is temporarily switched off during transmissions from the 9602/9602N.
o
As long as the 5V supply to the 9602/9602N is connected and the DC voltage on the GPS connector is
o
present, the GPS pass-through path is made available. The GPS path is available even when the
9602/9602N module has been turned off using its ON/OFF control signal.
If the GPS port is not used it may be left un-terminated with no adverse affect.
o
The GPS receiver must present 50 ohm impedance across the Iridium band or SBD performance could
o
be degraded.
The output return loss is typically -8 dB.
o
Proprietary & Confidential Information
Distribution of guide restricted to product developers only. • Information contained in this guide is subject to change without notice.
Table 11: Antenna Characteristics
Parameter
Impedance
Gain
Polarization
VSWR (maximum operational)
Value
50 Ohms nominal
3dBi
RHCP
1.5 : 1
30
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