Installation Manual

The transmission line should be designed according to the following guidelines:

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

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

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

• If EM noisy devices (such as fast switching ICs, LCD and so on) are present on the PCB hosting the

module, take care of the shielding of the antenna line by burying it in an inner layer 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;

The following image is showing the suggested layout for the Antenna pad connection:

PCB Guidelines in case of FCC Certification

In the case FCC certification is required for an application using the module, according to FCC KDB

996369 for modular approval requirements, the transmission line has to be similar to that implemented

on the module interface board and described in the following chapter.

Transmission line design

During the design of the module interface board, the placement of components has been chosen

properly, in order to keep the line length as short as possible, thus leading to lowest power losses

possible. A Grounded Coplanar Waveguide (G-CPW) line has been chosen, since this kind of