Most common causes
- Antenna is blocked by metal, battery or enclosure.
- Device is operating near noisy power electronics.
- 2.4 GHz channel is crowded.
- PCB antenna clearance is not respected.
- Transmit power, orientation or placement is poor.
How to test
Start with antenna placement, cable loss, power supply noise and final enclosure testing. Then compare RSSI, SNR, packet loss or return loss before and after each change.
What to verify
Check antenna frequency, matching network, connector type, ground plane, cable routing, supply ripple and nearby sources of interference.