Smart Module Series
SC262R_Series_Hardware_Design 85 / 115
⚫
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 not less than twice 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 Design Requirements
The following table shows the requirement on the main antenna, Rx-diversity antenna, Wi-Fi/Bluetooth
antenna and GNSS antenna.
Table 38: Antenna Design 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
Polarization Type: Vertical
Cable Insertion Loss: < 1 dB
