Using Elevated Radials in Conjunction with Deteriorated Buried-Radial Ground Systems

In the US, medium-wave broadcast stations utilize ground-mounted vertical monopole antennas with extensive buried-radial ground systems. Over a period of time, these radials may deteriorate, leading to a decrease in the radiated field strength of the antenna. Computer modeling studies indicate that, in such a situation, the addition of four elevated radials can restore performance to a level which is equal to or better than the original installation. Several different configurations for the elevated radials were investigated, including variations in their orientation, length, and height above ground. The computer software used for this work was the Numerical Electromagnetics Code (NEC) [1].