LN920 HW Design Guide
1VV0301730 Rev. 1
Page 57 of 81
2021-08-11
Not Subject to NDA
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If there are noisy EM devices around the PCB hosting the module, such as fast
switching ICs, shield antenna line by burying it inside the layers of PCB and
surrounding it with ground planes, or shielding it with a metal frame cover.
•
If there are no noisy EM devices around the PCB hosting the module, use a strip-
line on the superficial copper layer for the antenna line. The line attenuation will
be lower than a buried one.
8.2.2.
Hardware-Based Solution for GNSS and LTE Coexistence
When a stand-alone GNSS receiver is present in the user application, the transmitted LTE
signal may desensitize the GNSS receiver, especially if decoupling between the LTE and
GNSS antennas is low. A SAW filter can be added on LTE side to protect the GNSS receiver
from LTE out-of-band emissions, as described in the schematic below.
When the GNSS receiver embedded in the LN920 module is used, the LTE transmitter
and the GNSS receiver are never simultaneously active, thus filtering on the LTE side is
not needed.
Figure 6: Reference schematic
