Smart Module Series
SC200E_Series_Hardware_Design 82 / 115
In order to ensure RF performance and reliability, follow the principles below 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 pads, 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 curved ones. The recommended trace angle is 135°.
⚫
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 the width of RF signal
traces (2 × W).
⚫
Keep RF traces away from interference sources, and avoid intersection and paralleling between
traces on adjacent layers.
For more details about RF layout, see
document [3]
6.5. Antenna Installation
6.5.1. Antenna Requirements
The following table shows the requirements for the main antenna, Rx-diversity antenna, Wi-Fi/Bluetooth
antenna, and GNSS antenna.
Table 41: Antenna Requirements
Type
Requirements
GSM/WCDMA/LTE
VSWR: ≤ 2
Gain: 1 dBi
Max Input Power: 50 W
Input Impedance: 50
Ω
Polarization Type: Vertical
Cable insertion loss:
⚫
< 1 dB: LB (< 1 GHz)
⚫
< 1.5 dB: MB (1
–2.3 GHz)
⚫
< 2 dB: HB (> 2.3 GHz)
Wi-Fi/Bluetooth
VSWR:
≤ 2
Gain: 1 dBi
Max Input Power: 50 W
Input Impedance: 50
Ω
