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Smart Module Series
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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.
 Design the GND pins adjacent to RF pins as thermal relief pads, and fully connect them to ground.
 Keep the distance between the RF pins and the RF connector as short as possible. Change all the
right-angle traces to curved ones and the recommended trace angle is 135°.
 Reserve clearance under the signal pin of the antenna connector or solder joint.
 Keep the reference ground of RF traces complete. Meanwhile, add some ground vias around RF
traces and the reference ground 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 requirement on the main antenna, RX-diversity antenna, Wi-Fi/Bluetooth
antenna and a GNSS antenna.
Table 45: Antenna Requirements
Type Requirements
GSM/WCDMA/TD-SCDMA/
LTE
VSWR: ≤ 2
Gain:
GSM900: 2.38dBi
GSM1800: 1.33dBi
WCDMA Band 1/LTE Band 1: 1.53dBi
WCDMA Band 8/LTE Band 8: 2.98dBi
LTE Band 3: 2.0dBi
LTE Band 7: 3.0dBi
LTE Band 20: 2.64dBi
LTE Band 38: 2.3dBi
LTE Band 40: 1.88dBi
LTE Band 41: 3.6dBi
Max Input Power: 50 W
Input Impedance: 50 Ω
Polarization Type: Vertical