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6.3.1. Passive Antenna Reference Design
GNSS antenna interface supports passive ceramic antennas and other types of passive antennas. A
reference circuit design is given below.
LNA
Passive
Antenna
Module
ANT_GNSS
NM
C1
C2
L1
U1
C3
C4
NM
Figure 32: Reference Circuit Design for GNSS Passive Antenna
When the passive antenna is placed far away from the module (that is, the antenna trace is long) and the
external loss is more than 2 dB, it is recommended to add an external LNA circuit for better GNSS
receiving performance, and place the LNA close to the antenna.
6.3.2. Active Antenna Reference Design
In any case, it is recommended to use a passive antenna. If active antenna is indeed needed in your
application, it is recommended to reserve a π-type attenuation circuit provision and use high-performance
LDO as the power supply. The active antenna is powered by a 56 nH inductor through the antenna's
signal path. The common power supply voltage ranges from 3.3 V to 5.0 V. Despite its low power
consumption, the active antenna still requires stable and clean power supplies. Therefore, it is
recommended to use high-performance LDO as the power supply. A reference design for GNSS active
antenna is shown below.
NOTE
