GE865 Hardware User Guide
1vv0300799 Rev.9 – 27-07-2009
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page 33 of 70
This line of transmission shall fulfill the following requirements:
ANTENNA LINE ON PCB REQUIREMENTS
Impedance
50
Ω
Max Attenuation
0,3 dB
No 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.
7.2 GSM Antenna - PCB line Guidelines
•
Ensure that the antenna line impedance is 50
Ω
;
•
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;