Reference Design Of Rf Layout - Quectel RM502Q-GL Hardware Design

Table 26: GNSS Frequency
Type
GPS/Galileo/QZSS
Galileo
QZSS
GLONASS
BeiDou
NOTES
Keep the characteristic impedance for ANT_GNSS trace as 50 Ω.
1.
π-type
2. Place the matching components as close to the antenna as possible.
3. Digital circuits such as (U)SIM card, USB interface, camera module, display connector and SD card
should be kept away from the antenna traces.
4. Keep 75 dB isolation between two antenna traces.
5. Keep 15 dB isolation between each antenna to improve the receiving sensitivity.

5.3. Reference Design of RF Layout

For user's PCB, the characteristic impedance of all RF traces should be controlled as 50 Ω. The
impedance of the RF traces is usually determined by the trace width (W), the materials' dielectric constant,
the height from the signal layer to reference ground (H),
Microstrip or coplanar waveguide is typically used in RF layout for characteristic impedance control. The
following are reference designs of microstrip or coplanar waveguide with different PCB structures.
RM502Q-GL_Hardware_Design
Frequency
1575.42 ± 1.023 (L1)
1575.42 ± 2.046 (E1)
1575.42 (L1)
1597.5–1605.8
1561.098 ± 2.046
and the space between RF trace and ground
5G Module Series
RM502Q-GL Hardware Design
Unit
MHz
MHz
MHz
MHz
MHz
(S).
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