Rainbow Electronics GM862-GPS - Manual (Page 15)

GM862-GPS Hardware User Guide
1vv0300728 Rev. 8 - 20/09/07
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 15 of 73
4.2 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.
4.3 GPS Antenna Requirements
The GM862-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 (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)
The external active antenna for a Telit GM862-GPS device shall fulfill the following requirements:
ANTENNA REQUIREMENTS
Frequency range 1575.42 MHz (GPS L1)
Bandwidth +- 1.023 MHz
Gain 1.5 dBi < Gain < 4.5 dBi
Impedance 50 ohm
Amplification Typical 25dB (max 27dB)
Supply voltage Must accept from 3 to 5 V DC
Current
consumption Typical 20 mA (40 mA max)
Furthermore if the device is developed for the US market and/or Canada market, it shall comply to the
FCC and/or IC approval requirements:
This device is to be used only for mobile and fixed application.