Near Field Notes

Families2 notes

RF

A radio’s range comes up short.

Find your problem

What is the board doing wrong?

  1. aShort radio rangeAntenna ground
  2. bAntenna far from the radioTrace or U.FL jumper

Notes

2 notes
Four boards
Fig. 3c110 mm22%220 mm44%340 mm85%460 mm73%Fig. 3c110 mm22%220 mm44%340 mm85%460 mm73%Fig. 3c110 mm22%220 mm44%340 mm85%460 mm73%

Note 3Antenna ground

How much ground does a 2.4 GHz PCB antenna need?

85%radiated with 40 mm of ground

TI AN043 · CC2511 · CC2511 dongle

Loss against length
Fig. 25dLoss, dB0.511.522.500246810 cmTraceJumper2.0 cmFig. 25dLoss, dB0.511.522.500246810 cmTraceJumper2.0 cmFig. 25dLoss, dB0.511.522.500246810 cmTraceJumper2.0 cm
  • Trace
  • Jumper
  • Linx, 100 mm

Note 25Trace or U.FL jumper

When does a U.FL jumper beat a trace to the antenna?

83% vs 60%jumper vs trace, 10 cm at 5.5 GHz

U.FL · MHF I · 1.13 mm coax