Admittance of thin, coaxially-driven, infinite monopole antennas

The apparent admittance of an infinite monopole antenna, driven by coaxial line of inner radius a and outer radius b , is determined for the limit of small values of a/b , where kb « 1 Previous analytical work has determined the apparent admittance for the limit a/b → 1. These two results bracket and demonstrate the validity of earlier numerical work which determined the apparent admittance for 0 < a/b < 1 . The determination of the apparent admittance for a/b → 0 requires the asymptotic solution of an integral equation. In the derivation of the asymptotic solution to the original integral equation, new and very curious integral equation results. This new integral equation is examined analytically and finally is solved numerically.