User's Manual

GE/GC864-QUAD V2 and GE864-GPS Hardware User Guide
1vv0300915 Rev.2 – 2011-06-15
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights
Reserved. Page 51 of 97
7.2.3. GSM Antenna – Installation Guidelines
• Install the antenna in a place covered by the GSM
signal.
• The Antenna must be installed to provide a separation
distance of at least 20 cm from all persons and must
not be co-located or operating in conjunction with any
other antenna or transmitter;
• Antenna shall not be installed inside metal cases
• Antenna shall be installed also according Antenna
manufacturer instructions.
7.3. GPS Antenna (GE864-GPS only)
7.3.1. GPS Antenna Requirements
The GE864-GPS module is provided with an internal LNA
amplifier with two selectable gain level. By default the
GE864-GPS is configured in high gain mode (18dB with 2dB of
noise figure).
If the external antenna is connected to the DUT with a long
coax cable, the use of an external LNA close to the antenna
feed point is recommended. In this case the module must be
configured in low gain mode (8dB with 10dB of noise figure)
through a specific AT command (refer to AT$GPSAT on AT
Commands Reference Guide, 80000ST10025a). The module provides
a digital output signal (GPS_LNA_EN) used for RF power control
that can be used to enable the external LNA.
NOTE: when the internal LNA is in high gain mode, the
GPS_LNA_EN output is tied low (external LNA unused).
NOTE: The typical external gain range is 20 dB (when in low
gain mode, not recommended in high gain mode)