Antennas

Polarization

• Vertical
• Horizontal
• Circular
• Point-to-point - antennas must have the same polarization

Radiation Patterns

• Radiation pattern chart -  describes the signal sent by an antenna
• There are two fields that antennas radiate their power
• E-Plane
  • The elevation plane, or elevation chart - side view
  • Composes the electric field vector
• H-Plane
• The horizontal plane, or azimuth chart - top view
• Composes the magnetic field vector

Beamwidth - area where most of the energy is being radiated

Types

• Omnidirectional - usually radiate equally in all directions in the H-plane, but not on the E-plane
• Most common is Dipole (2.2 dBi)

• Directional - usually designed to cover both planes in one direction
• Most common Patch (10 dBi) and Yagi (13 dBi)

Accessories

• Connectors
  • Cisco Aps
    •  reverse-polarity threaded Neill-Concelman connector (RP-TNC)
    • N connector - for outdoor use
  • Others common connectors
    • Subminiature Version A (SMA)
    • Reverse-polarity SMA (RP-SMA)
    • Multipoint controller (MC)
    •  Multimedia communication exchange (MMCX)
• Cables
  • Decrease the amplitude
• Amplifiers
  • Increase the amplitude
• Lightning arrestor
  • Circuit breaker that dissipate static electricity

Effective Isotropic Radiated Power (EIRP)

• Total power radiated fro the antenna

EIRP (dBm) = Radio Transmitted power (dBm) + antenna gain (dBi) – cable loss (dB)