User's Manual

7. Antenna
The antenna connection and board layout design are the most important aspect in the full
product design as they strongly affect the product overall performances, hence read carefully
and follow the requirements and the guidelines for a proper design.
7.1. GSM Antenna Requirements
As suggested on the Product Description the antenna and antenna transmission line on PCB for a
Telit GE865 device shall fulfil the following requirements:
ANTENNA REQUIREMENTS
Frequency range
Depending by frequency band(s) provided by the network
operator, the customer shall use the most suitable antenna
for that/those band(s)
Bandwidth
70 MHz in GSM850, 80 MHz in GSM900, 170 MHz in
DCS & 140 MHz PCS band
Gain
1.4dBi @900 and 3dBi @1800
1.4dBi @850 and 3dBi @1900
Impedance
50Ω
Input power
> 2 W
VSWR absolute max
≤ 10:1 (limit to avoid permanent damage)
VSWR recommended
≤ 2:1 (limit to fulfil all regulatory requirements)
When using the GE865, since there's no antenna connector on the module, the antenna must be
connected to the GE865 antenna pad (BGA Ball H5) by means of a transmission line
implemented on the PCB.
In the case the antenna is not directly connected at the antenna pad of the GE865, then a PCB
line is needed in order to connect with it or with its connector.
This transmission line shall fulfill the following requirements:
ANTENNA LINE ON PCB REQUIREMENTS
Characteristic Impedance
50Ω
Max Attenuation
0,3 dB
Coupling with other signals shall be avoided
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