Full-Wave Dipole Antenna

If the length of the dipole, i.e. the total wire, equals the full wavelength λ, then it is called as full wave dipole. If a full wavelength dipole is used either for transmission or for reception, let us see how the radiation will be.

The full-wave dipole with its voltage and current distribution is shown here. Both the positive and negative peaks of the wave induce positive and negative voltages respectively. However, as the induced voltages cancel out each other, there is no question of radiation.

The above figure shows the voltage distribution of full-wave dipole whose length is λ. It is seen that two half-wave dipoles are joined to make a full-wave dipole.

The voltage pattern when induces its positive charges and negative charges at the same time, cancel out each other as shown in the figure. The induced charges make no further attempt of radiation since they are cancelled. The output radiation will be zero for a fullwave transmission dipole.

As there is no radiation, there is no question of radiation pattern for this full-wave dipole.

The following are the disadvantages of full-wave dipole antenna.

• Heat dissipation
• Wastage of power
• No radiation pattern
• No directivity and no gain

Due to these drawbacks, the full-wave dipole is seldom used.