Product Info

Smart LTE Module Series
SC20 Hardware Design
SC20_Hardware_Design 82 / 130
Table 39: GNSS Frequency
Type
Frequency
Unit
GPS
1575.42±1.023
MHz
GLONASS
1597.5~1605.8
MHz
BeiDou
1561.098±2.046
MHz
6.3.1. Recommended Circuit 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
L1
U1
C3
C4
NM
Figure 37: 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), it is
recommended to add an external LNA circuit for better GNSS receiving performance, and the LNA should
be placed close to the antenna.
6.3.2. Recommended Circuit for Active Antenna
The active antenna is powered by VCC power supply through the R1 and L1 power paths shown in the
following figure. The common power supply voltage ranges from 3.3V to 5.0V. 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.
NOTE