Antennas

Half Wave Antenna (3)

  • An antenna that is shorter than a half wavelength at the frequency of operation will have capacitive reactance as well as resistance at its feed point
  • An antenna that is longer than a half wavelength at the frequency of operation will have inductive reactance as well as resistance at its feed point
  • An aerial tuning unit would generally be used to “tune out” the capacitive or inductive reactance and present a resistive load to the 50Ω output of the transmitter (Tx)
  • The antenna system and Tx are then said to be “matched