Neoway N720 - 3 RF Interface; 3.1 2 G;3 G;4 G RF Design and PCB Layout

N720 Hardware User Guide
Copyright © Neoway Technology Co., Ltd 36
3 RF Interface
Name
Pin
I/O
Function
Remarks
ANT_MAIN
76
AI/O
2G/3G/4G main antenna
50 Ω characteristic impedance
ANT_GNSS
92
AI
GNSS antenna
ANT_AUX
94
AI
4G diversity aerial
3.1 2G/3G/4G RF Design and PCB Layout
ANT_MAIN and ANT_AUX are the antenna pins of N720. A 50 Ω antenna is required. VSWR ranges
from 1.1 to 1.5. The antenna should be well matched to achieve best performance. It should be installed
far away from high-speed logic circuits, DC/DC power or any other strong disturbing sources.
A 50 Ω antenna is required. VSWR ranges from 1.1 to 1.5. The antenna should be well matched to
achieve best performance.
For multiple-layer PCB, the trace between the antenna pad of module and the antenna connector, should
have a 50 Ω characteristic impedance, and be as short as possible. The trace should be surrounded by
ground copper. Place plenty of via holes to connect this ground copper to main ground plane, at the copper
edge.
For dual-layer PCB, the width of recommended impedance trace is 0.8 mm to 1 mm and the grounding
copper should away from the trace for 1 to 1.5 time of the trace width.
If the trace between the module and connector has to be longer, or built-in antenna is used, add a π-type
matching as shown in Figure 3-1.
Figure 3-1 Reference of antenna matching design