2 gsm antenna - pcb line guidelines – Rainbow Electronics GE863-PY User Manual

Page 30

GE863 Hardware User Guide

1vv0300783 Rev.0 - 10/06/08

page 30 of 80

This line of transmission shall fulfil the following requirements:

ANTENNA LINE ON PCB REQUIREMENTS

Impedance

50 ohm

Max Attenuation

0,3 dB

No coupling with other signals allowed
Cold End (Ground Plane) of antenna shall be equipotential to
the GE863 ground pins

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. 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. End-Users must be
provided with transmitter operation conditions for satisfying RF exposure compliance. OEM integrators
must ensure that the end user has no manual instructions to remove or install the GE863 module.
Antennas used for this OEM module must not exceed 3dBi gain for mobile and fixed operating
configurations.

5.2 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 GE863 antenna line;

• Keep the antenna line far away from the GE863 power supply lines;

• If you have EM noisy devices around the PCB hosting the GE863, 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 GE863, by using a strip-line on the

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