Specifications

Cinterion
®
ALAS66A Hardware Interface Overview
2.2 GSM/UMTS/LTE Antenna Interface
33
 ALAS66A_HIO_v01.000a 2019-02-26
Confidential / Released
Page 25 of 51
2.2.1 Antenna Installation
The antennas are connected by soldering the antenna pads (ANT_TRX1, ANT_TRX2,
ANT_RX3, ANT_RX4; ANT_GNSS) and their neighboring ground pads directly to the applica-
tion’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 must 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 Sec-
tion 2.2.2 for instructions of how to design the antenna connection in order to achieve the
required 50
 line impedance.
For type approval purposes(i.e., FCC KDB 996369 related to modular approval requirements),
an external application must connect the RF signal in one of the following ways:
•Via 50
 coaxial antenna connector (common connectors are U-FL or SMA) placed as close
as possible to the module's antenna pad.
• By soldering the antenna to the antenna connection line on the application’s PCB (without
the use of any connector) as close as possible to the module’s antenna pad.
• By routing the application PCB’s antenna to the module’s antenna pad in the shortest pos-
sible way.