Справочник Пользователя для Gemalto M2M GmbH ALS3-USR4
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ALS3-US R4 Hardware Interface Overview
5.1 GSM/UMTS/LTE Antenna Interface
34
ALS3-USR4_HIO_v03.915
2017-03-27
Confidential / Preliminary
Page 29 of 44
5.1.1
Antenna Installation
The antenna is connected by soldering the antenna pads (ANT_MAIN; ANT_DRX_MIMO) and
their neighboring ground pads directly to the application’s PCB.
their neighboring ground pads directly to the application’s PCB.
The distance between the antenna pads and their neighboring GND pads has been optimized
for best possible impedance. To prevent mismatch, special attention should be paid to these
pads on the application’ PCB.
for best possible impedance. To prevent mismatch, special attention should be paid to these
pads on the application’ PCB.
The wiring of the antenna connection, starting from the antenna pad to the application’s anten-
na should result in a 50
na should result in a 50
line impedance. Line width and distance to the GND plane need to
be optimized with regard to the PCB’s layer stack.
To prevent receiver desensitization due to interferences generated by fast transients like high
speed clocks on the external application PCB, it is recommended to realize the antenna con-
nection line using embedded Stripline rather than Micro-Stripline technology. Please see
speed clocks on the external application PCB, it is recommended to realize the antenna con-
nection line using embedded Stripline rather than Micro-Stripline technology. Please see
for examples of how to design the antenna connection in order to achieve the
required 50
line impedance.
For type approval purposes, the use of a 50
coaxial antenna connector (U.FL-R-SMT) might
be necessary. In this case the U.FL-R-SMT connector should be placed as close as possible
to ALS3-US R4‘s antenna pad.
to ALS3-US R4‘s antenna pad.