Wi-Fi&Bluetooth Module Series
AF20_Hardware_Design
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To ensure better RF performance and reliability, the following conditions 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.
GND pins adjacent to RF pins should not be designed as thermal relief pads, and should be fully
connected to ground.
Clearance between RF pins and RF connector should be as short as possible, and all right-angle
(90°) traces should be changed to the ones with the angle of 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, ground vias around RF traces
and the reference ground can improve RF performance. The clearance between ground vias and RF
traces should be at least twice the width of RF signal traces (2 × W).
Keep RF traces away from interference sources, and avoid intersection and paralleling between any
traces on adjacent layers.
For more details about RF layout, see
document [3]
.
3.9.5. Requirements for Antenna Design
Table 15: Antenna Requirements
Type
Requirements
Frequency Range
2.412 GHz–2.472GHz (cable Insertion Loss: < 1 dB)
5.180 GHz–5.825GHz (cable Insertion Loss: < 1 dB)
VSWR
≤
2
Gain (dBi)
1 (typ.)
Max Input Power (W)
50
Input Impedance (Ω)
50
Polarization Type
Vertical
3.9.6. RF Connector Recommendation
If RF connector is used for antenna connection, it is recommended to use the U.FL-R-SMT connector
provided by Hirose.