User's Manual

Cinterion
®
ALAS6A-US Hardware Interface Overview
2.2 GSM/UMTS/LTE Antenna Interface
22
 ALAS6A-US_HIO_v00.130a 2016-09-28
Confidential / Preliminary
Page 19 of 40
2.2.2.2 Routing Examples
Interface to RF Connector
Figure 7 shows a sample connection of a module‘s antenna pad at the bottom layer of the mod-
ule PCB with an application PCB‘s coaxial antenna connector. Line impedance depends on line
width, but also on other PCB characteristics like dielectric, height and layer gap. The sample
stripline width of 0.40mm is recommended for an application with a PCB layer stack resembling
the one of the ALAS6A-US evaluation board. For different layer stacks the stripline width will
have to follow stripline routing rules, avoiding 90 degree corners and using the shortest dis-
tance to the PCB’s coaxial antenna connector.
Figure 7: Routing to application‘s RF connector
e.g.
ANT_
MAIN
G N D
G N D
Edge of module PCB
Stripline (50 ohms) on top
layer of evaluation board from
antenna pad to module edge
Width = 0.40 mm
E.g., U.FL antenna
connector
50 ohms microstrip line
G N D G N D
Ground connection
G N D G N D