Impedance stability and bandwidth considerations for elevated-radial antenna systems

An examination is made of the variations in feed-point impedance that occur in an elevated antenna system due to changes in the electrical characteristics of the underlying soil. The bandwidth of such antennas is also investigated by looking at deviations in the input impedance as the operating frequency is varied about its nominal value. In all cases, results for the elevated antenna are compared with those of the conventional ground-mounted system. The computer program used for this work was NEC (Numerical Electromagnetics Code), a method-of-moments software package.<
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