LE940B6 HW User Guide
Rev. 2.02
Page 67 of 111
2020-01-10
•
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 22: 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.
GSM/WCDMA/TD-SCDMA/LTE Antenna
– Installation Guidelines
•
Install the antenna in a location with access to the network radio signal.
•
The antenna must be installed such that it provides 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.
•
The antenna must not be installed inside metal cases.
•
The antenna must be installed according to
the antenna manufacturer’s
instructions.
Provided
to
Dekra
under
NDA
Distribution
is
Prohibited
except
for
Dekra
employees
with
a Need
to
know
