An Overview of the Natural Frequencies of a Straight Wire by Various Methods

There are a number of different methods for computing the natural frequencies of a straight wire antenna or scatterer. The most accurate method is that derived from a numerical solution to the integral equation for the wire current. Due to the relative difficulty in obtaining this solution, however, several different approximations to natural frequencies have been developed and used in the past. Most recently, a paper by Meyers, has described a variational approach for computing these natural frequencies. This paper provides a brief description of each of these methods for determining the natural frequencies of a straight wire, and then presents a comparison of the result of each method for a wire of diameter to length ratio (
d
/
L
) ranging from 0 to 0.1.