Q: What are the key considerations for RF and antenna PCB layout (BLE WiFi LoRa)?
Answer
For BLE/WiFi/LoRa modules on PCB: keep RF trace short (<10 mm) and use a 50 Ohm coplanar waveguide with ground reference. For chip antennas follow the vendor keep-out zone precisely - no copper traces or components within the specified clearance. Ground plane clearance around antenna: typically 5-10 mm for chip antennas. Use a matching network (inductor/capacitor) to tune antenna impedance - measured with a VNA. For external whip antennas use a 50 Ohm coax (U.FL/SMA) connector. LoRa nodes benefit from a proper ground plane (at least lambda/10 in diameter). Avoid routing USB or switching regulator traces near the antenna.
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