Gemalto M2M GmbH ALS1-US Manual Do Utilizador

®

4.1 GSM/UMTS/LTE Antenna Interface

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ALS1-US_HIO_v01.000

2013-08-14

Confidential / Preliminary

Page 25 of 34

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.

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.

The wiring of the antenna connection, starting from the antenna pad to the application’s anten-

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.

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 ALS1-US‘s antenna pad.