Hardware Guide

Table Of Contents

GE865 Hardware User Guide

1vv0300799 Rev.15– 2012-04-23

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

• Make sure that the transmission line’s characteristic impedance is 50Ω ;

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

around 0,3 dB;

• Line geometry should have uniform characteristics, constant cross section, avoid

meanders and abrupt curves;

• Any kind of suitable geometry / structure (Microstrip, Stripline, Coplanar, Grounded

Coplanar Waveguide...) can be used for implementing the printed transmission line

afferent the antenna;

• If a Ground plane is required in line geometry, that plane has to be continuous and

sufficiently extended, so the geometry can be as similar as possible to the related

canonical model;

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

possible, use this layer as reference Ground plane for the transmission line;

• It is wise to surround (on both sides) the PCB transmission line with Ground, avoid

having other signal tracks facing directly the antenna line track.

• Avoid crossing any un-shielded transmission line footprint with other signal tracks on

different layers;

• The ground surrounding the antenna line on PCB has to be strictly connected to the main

Ground Plane by means of via holes (once per 2mm at least), placed close to the ground

edges facing line track;

• 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 EM noisy devices are present on 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 EM noisy devices are not present around the line, the use of geometries like Microstrip

or Grounded Coplanar Waveguide has to be preferred, since they typically ensure less

attenuation if compared to a Stripline having same length;