User's Manual

GE865 Hardware User Guide

1vv0300799 Rev.6 - 04/06/09

This line of transmission shall fulfill the following requirements:

ANTENNA LINE ON PCB REQUIREMENTS

Impedance

50 ohm

Max Attenuation

0,3 dB

o coupling with other signals allowed

Cold End (Ground Plane) of antenna shall be equipotential to

the GE865 ground pins

Furthermore if the device is developed for the US market and/or Canada market, it shall comply with

the FCC and/or IC approval requirements:

This device is to be used only for mobile and fixed application. In order to re-use the Telit FCC/IC

approvals the antenna(s) used for this transmitter 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. If antenna is installed with a separation distance of less than 20 cm from all

persons or is co-located or operating in conjunction with any other antenna or transmitter then

additional FCC/IC testing may be required. End-Users must be provided with transmitter operation

conditions for satisfying RF exposure compliance.

Antennas used for this OEM module must not exceed 3dBi gain for mobile and fixed operating

configurations.

6.2 GSM Antenna - PCB line Guidelines

• Ensure that the antenna line impedance is 50 ohm;

• Keep the antenna line on the PCB as short as possible, since the antenna line loss shall be less

than 0,3 dB;

• Antenna line must have uniform characteristics, constant cross section, avoid meanders and

abrupt curves;

• Keep, if possible, one layer of the PCB used only for the Ground plane;

• Surround (on the sides, over and under) the antenna line on PCB with Ground, avoid having other

signal tracks facing directly the antenna line track;

• The ground around the antenna line on PCB has to be strictly connected to the Ground Plane by

placing vias once per 2mm at least;

• Place EM noisy devices as far as possible from GE865 antenna line;

• Keep the antenna line far away from the GE865 power supply lines;

• If you have EM noisy devices around the PCB hosting the GE865, such as fast switching ICs, take

care of the shielding of the antenna line by burying it inside the layers of PCB and surround it with

Ground planes, or shield it with a metal frame cover.

• If you don't have EM noisy devices around the PCB of GE865, by using a strip-line on the

superficial copper layer for the antenna line, the line attenuation will be lower than a buried one;