Rainbow Electronics GE863-PY - Manual (Page 31)

GE863 Hardware User Guide
1vv0300783 Rev.0 - 10/06/08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 31 of 80
5.3 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.
5.4 GPS Antenna Requirements
The GE863-GPS module is not provided with an internal LNA amplifier. The use of an active antenna
is important to achieve a good performance.
The module is provided of an Antenna supply circuit with the following characteristics:
• Supply voltage referred to VBATT (Must accept values from 3.4 to 4.2 V DC)
• Supply enable controlled internally by the BB
• Current measurement circuit (readable also with AT commands)
• Voltage measurement circuit (readable also with AT commands)
• HW Protection for Antenna Short Circuit (if consumption exceeds 40mA)
5.4.1 Combined GPS Antenna
The use of combined GPS antennas is NOT recommended; this solution could generate an extremely
poor GPS reception and also the combination antenna requires additional diplexer and adds a loss in
the RF route.
5.4.2 Linear and Patch GPS Antenna
Using this type of antenna introduces at least 3 dB of loss if compared to a circularly polarized (CP)
antenna. Having a spherical gain response instead of a hemispherical gain response could aggravate
the multipath behaviour & create poor position accuracy.