Introduction
A monopole antenna is a vertical antenna with a quarter wavelength. The antenna is mounted on a ground plane, which may be the actual ground or an artificial ground plane such as a vehicle body. The feeding of the monopole antenna is performed using a coaxial cable at the lower end, and the grounding conductor of the feeder is connected to the platform. In free space, the radiation pattern of a quarter-wave monopole antenna in a vertical plane is similar to that of a half-wave dipole antenna in a vertical plane, but without underground radiation. On a horizontal plane, the vertical monopole antenna is omnidirectional.
