Monopole Vertical Antennas

A monopole vertical antenna is actually a dipole antenna which is created by taking one-half of the dipole as the vertical resonator while the ground plane is at right angle to it. Believe it or not a monopole will actually have a directive gain somewhere in the neighborhood of 5+db. Monopole antennas are used for more than just amateur radio, they are also found in navigation beacons as well as the more well-known broadcast stations.



Monopole antennas are generally a quarter wavelength in size but can be either shorter or longer. The monopole vertical antenna depends upon the ground radial system to be effective and you will normally see 120 radials in place. So you see that the debate about whether to use radials or not does not pertain to monopoles as they simply will not work without them.