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6.3.1. Reference Circuit Design for Passive Antenna
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
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. Reference Circuit Design for Active Antenna
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. Although featuring low power consumption, the active
antenna still requires stable and clean power supplies. It is recommended to use high-performance LDO
as the power supply. A reference design of GNSS active antenna is shown below.
Active Antenna
3V3
Module
ANT_GNSS
56nH
10R
1uF
100pF
NM
NM
C4
C1
R1
L1
R2
0R
C5
C3
C2
100pF
Figure 33: Reference Circuit Design for GNSS Active Antenna
NOTE