Smart Module Series
SC606T Series Hardware Design
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Figure 34: Coplanar Waveguide Design on a 4-layer PCB (Layer 4 as Reference Ground)
To ensure RF performance and reliability, the following principles should be complied with in RF layout
design:
⚫
Use an impedance simulation tool to accurately control the characteristic impedance of RF traces to
50
Ω.
⚫
The GND pins adjacent to RF pins should not be designed as thermal relief pins and should be fully
connected to ground.
⚫
The distance between the RF pins and the RF connector should be as short as possible, and all the
right-angle traces should be changed to curve ones.
⚫
There should be clearance under the signal pin of the antenna connector or solder joint.
⚫
The reference ground of RF traces should be complete. Meanwhile, adding some ground vias around
RF traces and the reference ground could help to improve RF performance. The distance between
the ground vias and RF traces should be no less than two times as wide as RF signal traces (2 × W).
For more details about the RF layout, see
document [3].
6.2. Wi-Fi/BT and FM Antenna Interfaces
The pin definition of Wi-Fi/BT and FM antenna interfaces and operating frequencies are shown below.
Table 34: Pin Definition of Wi-Fi/BT and FM Antenna Interfaces
Pin Name
Pin No.
I/O
Description
Comment
ANT_WIFI/BT
129
AIO
Wi-Fi/BT antenna interface
50
Ω impedance
ANT_FM
244
AI
FM antenna interface
50
Ω impedance