Antennas

Half Wave Antenna (1)

  • The fundamental antenna is a length of wire which is an electrical half wavelength long
  • The antenna is said to be resonant at the frequency at which it is an electrical half wavelength long;  at the resonant frequency it will present a resistive load
  • The voltage and current distribution on a half wave antenna is shown above
  • Note that the voltage is highest (greatest danger of RF burns!!) at the ends of a half wave dipole
  • At the centre of a half wave dipole, the current will be highest and the voltage low
  • Similarly, at the base of a quarter wave antenna, the current will be highest and the voltage low