5G Module Series
RM502Q-GL Hardware Design
RM502Q-GL_Hardware_Design 52 / 77
5.1.4. Reference Design of RF Antenna Interface
A reference design of antenna interface is shown as below. A
π-type matching circuit should be reserved
for better RF performance. The capacitors are not mounted by default.
Module
ANT3
ANT0
R1 0
Ω
R4 0
Ω
C1
NM
C2
NM
C8
NM
C7
NM
Figure 30: Reference Circuit of RF Antenna
1.
Keep the characteristic impedance for antenna trace as 50
Ω.
2. Place the
π-type
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 PCB isolation between two antenna traces.
5. Keep 15 dB isolation between
each
antenna to improve the receiving sensitivity.
6. It is suggested to keep 20 dB isolation between 5G NR UL MIMO Tx0 and Tx1 antennas.
5.2. GNSS Antenna Interface
The following table shows frequency specification of GNSS antenna connector.
n78
3300
–
3800
3300
–
3800
–
–
–
n78
NOTES