Regulatory Information - SimCom SIM900E User Manual

SIM900E Document
Fill the area around the RF traces with ground and ground vias to connect inner ground layers
for isolation.
Cut out ground under RF signal pads to reduce stray capacitance losses.
Avoid routing RF traces with sharp corners. A smooth radius is recommended.
The ground reference plane should be a solid continuous plane under the trace.
The coplanar clearance (G, below) from the trace to the ground should be at least the trace width (W) and at
least twice the height (H). This reduces the parasitic capacitance, which potentially alters the trace impedance
and increases the losses. Note the figure below shows several internal ground layers cutout, which may not
be necessary for every application.

6. Regulatory Information

Important notice
Because of the nature of wireless communications, transmission and reception of data can never be guaranteed.
Data may be delayed, corrupted (i.e., have errors) or be total y lost.
Figure 6: RF routing examples
Figure 7: Coplanar clearance example
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