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FIBOCOM SC138-
NA
Series Hardware Guide
68/88
Table 3-24 GNSS band
Mode
Frequency Band
Unit
GPS
1575.42±1.023
MHz
GLONASS
1597.42-1605.8
MHz
BeiDou
1561.098±2.046
MHz
3.22.2
Circuit Reference Design
The LNA is built into the SC138 series module, and the passive antenna is selected in the whole
machine design. Microstrip line is recommended for the GNSS RF routing, the insertion loss is controlled
within 0.2 dB, and the impedance is controlled within 50 Ω. The connection reference circuit is shown in
the following figure:
Figure 3-27-1 Reference circuit of GNSS passive antenna
The reference circuit of active antenna is shown in the following figure:
M odule
A N T_G N S S
G N S S _A ntenna
N C
0R
N C