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Calculates antenna directivity and gain compared to isotropic radiator. Shows how antenna concentrates power in preferred direction.

Formel

Gain (dBi) = 10 × log10(power density vs. isotropic)

Trin-for-trin guide

  1. 1Gain (dBi) = 10 × log10(power density vs. isotropic)
  2. 2Omnidirectional antennas 0-3 dBi
  3. 3Directional antennas 5-20+ dBi
  4. 4Gain trade-off: narrower pattern = higher gain
  5. 5Efficiency factor: practical gain < theoretical

Løste eksempler

Input
Dipole antenna
Resultat
2.15 dBi

Almindelige fejl at undgå

  • Confusing antenna gain with amplifier gain
  • Not accounting for free space path loss

Ofte stillede spørgsmål

What's the difference between dBi and dBd?

dBi: vs. isotropic point source; dBd: vs. dipole; dBi = dBd + 2.15.

How does antenna gain improve range?

6 dB gain = 2× power (doubles range); 10 dB = 10× power (3.16× range).

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