Understanding Antennas

0dB 為Antenna最強可達位

Antenna gain 即是集中RF能力

理論天線為一點, Gain為0 dBi, 沒RF集中能力

Beamwidth: 在-3dBm畫線, 計角度

Polarization: Tx 及 Rx 要parallel傳接

• Omnidirectional Antennas (Dipole)
  • Distributes all direction -> low gain
  • Dipole
  • Gain +2 to +5 dBi

• Omnidirectional Antenna (Monopole)

• Directional Antenna (Patch)
  • Gain 6 to 8 dBi in 2.4GHz
  • Gain 7 to 10 dBi in 5GHz

• Directional Antennas (Yagi)
  • Gain 10 to 14 dBi in 2.4GHz

• Directional Antennas (Parabolic Dish)

• Amplifier

• Attenuator

• Lightning Arrestor