Specifications

Cinterion
®
EXS82-W Hardware Interface Overview
2.2 RF Antenna Interface
25
 EXS82-W_HIO_v00.038 2019-12-27
Public / Preliminary
Page 17 of 44
2.2.1 Antenna Installation
The antennas is connected by soldering the antenna pads (RF_OUT, ANT_GNSS) and its
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. On the application PCB, special attention should be paid to these
pads, in order to prevent mismatch.
The wiring of the antenna connection line, starting from the antenna pad to the application an-
tenna should result in a 50
Ω line impedance. Line width and distance to the GND plane needs
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 application PCB, it is recommended to realize the antenna connection line
using embedded Stripline rather than Micro-Stripline technology.
For type approval purposes, the use of a 50
Ω 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 EXS82-W‘s antenna pad.
2.2.2 RF Line Routing Design
2.2.2.1 Line Arrangement Examples
Several dedicated tools are available to calculate line arrangements for specific applications
and PCB materials - for example from http://www.polarinstruments.com/ (commercial software)
or from http://web.awrcorp.com/Usa/Products/Optional-Products/TX-Line/ (free software).
Embedded Stripline
This figure below shows a line arrangement example for embedded stripline with 65µm FR4
prepreg (type: 1080) and 710µm FR4 core (4-layer PCB).
Figure 6: Embedded Stripline with 65µm prepreg (1080) and 710µm core