5G Module Series
RM505Q-AE Hardware Design
RM505Q-AE_Hardware_Design 54 / 79
Table 27: GNSS Frequency
VDD 1.7 V
GNSS Antenna
47 nH
56 pF
ESD Protector
ANT4_GNSS
18R
GPS matching
Figure 28: Reference Circuit of GNSS Antenna
1. Keep the characteristic impedance for the trace of GNSS antenna (
ANT4_GNSS)
to 50
Ω.
2. Place the
π-type
matching components as close to the antenna as possible.
3. Keep the digital circuits, such as that of (U)SIM card, USB interface, camera module, display
connector and SD card, away from the antenna traces.
4. Keep 75 dB isolation between each two antenna traces.
5. Keep 15 dB isolation between each two antenna to improve the receiving sensitivity.
Type
Frequency
Unit
GPS/Galileo/QZSS
1575.42±1.023 (GPS L1)
1176.45±10.23 (GPS L5)
MHz
Galileo
1575.42 ±2.046 (E1)
MHz
QZSS
1575.42 (L1)
MHz
GLONASS
1597.5
–1605.8
MHz
BeiDou
1561.098 ±2.046
MHz
NOTES