User's Manual

LE940B6 Hardware User Guide

1VV0301331 Rev. 1.8 - 2017-03-15

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• If a ground plane is required in the line geometry, this plane must 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.

• Surround the PCB transmission line with ground (on both sides). Avoid having other signal

tracks facing the antenna line track directly.

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

layers.

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

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

edges facing the line track.

• Place EM-noisy devices as far as possible from LE940B6 antenna line.

• Keep the antenna line far away from the LE940B6 power supply lines.

• If EM-noisy devices are present on the PCB hosting the LE940B6, such as fast switching ICs,

take care to shield them with a metal frame cover.

• If EM-noisy devices are not present around the line, geometries like Micro strip or Grounded

Coplanar Waveguide are preferred because they typically ensure less attenuation compared

to a Strip line having the same length.

This transmission line must meet the following requirements:

Table 23: Antenna Line on PCB Requirements

Characteristic impedance 50 Ohm

Max attenuation 0.3 dB

Avoid coupling with other signals.

Cold End (Ground Plane) of the antenna must be equipotential to the LE940B6 ground pads.

Furthermore if the device is developed for the US and/or Canada market, it must comply with 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

LE940B6 module. Antennas used for this OEM module must not exceed 3dBi gain for mobile and

fixed operating configurations.