User Guide

Iridium Communications Inc. Information Contained in this Guide
9602 SBD Transceiver Product Developers Guide is Subject to Change Without Notice
Revision 1.2 (DRAFT 2)
Iridium Communications Inc. Distribution of Guide Restricted
Proprietary & Confidential Information 29 to Product Developers Only
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.
Table 11: Antenna Characteristics
Parameter Value
Impedance 50 Ohms nominal
Gain 3dBi
Polarization RHCP
VSWR (maximum operational) 1.5 : 1
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.
o The GPS pass-through path is activated by detecting the presence of a DC voltage on the center-
pin of 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).
o There is a gain of approximately -3dB (9602) / +5.0dB (9602N) in the receive direction from ANT
to GPS.
o 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 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.
o 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 be degraded.
o The output return loss is typically -8 dB.