Data Sheet

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1. GENERAL RF GUIDELINES
Follow these steps for optimal WLAN performance.
1. Control WLAN 50 ohm RF traces by doing the following:
• Route traces on the top layer as much as possible and use a continuous reference ground
plane underneath them.
• Verify trace distance from ground flooding. At a minimum, there should be a gap equal to the
width of one trace between the trace and ground flooding. Also keep RF signal lines away from
metal shields. This will ensure that the shield does not detune the signals or allow for spurious
signals to be coupled in.
• Keep all trace routing inside the ground plane area by at least the width of a trace.
• Check for RF trace stubs, particularly when bypassing a circuit.
2. Keep RF traces properly isolated by doing the following:
• Do not route any digital or analog signal traces between the RF traces and the reference
ground.
• Keep the balls and traces associated with RF inputs away from RF outputs. If two RF traces
are close each other, then make sure there is enough room between them to provide isolation
with ground fill.
• Verify that there are plenty of ground vias in the shield attachment area. Also verify that there
are no non-ground vias in the shield attachment area. Avoid traces crossing into the shield
area on the shield layer.
3. Consider the following RF design practices:
• Confirm antenna ground keep-outs.
• Verify that the RF path is short, smooth, and neat. Use curved traces or microwave corners
for all turns; never use 90-degree turns. Avoid width discontinuities over pads. If trace widths
differ significantly from component pad widths, then the width change should be mitered.
Verify there are no stubs.
• Do not use thermals on RF traces because of their high loss.
• The RF traces between AW-AM510 RF_ANT pin and antenna must be made using 50Ω
controlled-impedance transmission line.